1VI(1P) POSIX Programmer's Manual VI(1P)
2
6 This manual page is part of the POSIX Programmer's Manual. The Linux
7 implementation of this interface may differ (consult the corresponding
8 Linux manual page for details of Linux behavior), or the interface may
9 not be implemented on Linux.
10
13 vi — screen-oriented (visual) display editor
14
16 vi [−rR] [−c command] [−t tagstring] [−w size] [file...]
17
19 This utility shall be provided on systems that both support the User
20 Portability Utilities option and define the POSIX2_CHAR_TERM symbol.
21 On other systems it is optional.
22 The vi (visual) utility is a screen-oriented text editor. Only the open
24 and visual modes of the editor are described in POSIX.1‐2008; see the
25 line editor ex for additional editing capabilities used in vi. The
26 user can switch back and forth between vi and ex and execute ex com‐
27 mands from within vi.
28 This reference page uses the term edit buffer to describe the current
30 working text. No specific implementation is implied by this term. All
31 editing changes are performed on the edit buffer, and no changes to it
32 shall affect any file until an editor command writes the file.
33 When using vi, the terminal screen acts as a window into the editing
35 buffer. Changes made to the editing buffer shall be reflected in the
36 screen display; the position of the cursor on the screen shall indicate
37 the position within the editing buffer.
38 Certain terminals do not have all the capabilities necessary to support
40 the complete vi definition. When these commands cannot be supported on
41 such terminals, this condition shall not produce an error message such
42 as ``not an editor command'' or report a syntax error. The implementa‐
43 tion may either accept the commands and produce results on the screen
44 that are the result of an unsuccessful attempt to meet the requirements
45 of this volume of POSIX.1‐2008 or report an error describing the termi‐
46 nal-related deficiency.
47
49 The vi utility shall conform to the Base Definitions volume of
50 POSIX.1‐2008, Section 12.2, Utility Syntax Guidelines, except that '+'
51 may be recognized as an option delimiter as well as '−'.
52 The following options shall be supported:
54 −c command
56 See the ex command description of the −c option.
57 −r See the ex command description of the −r option.
59 −R See the ex command description of the −R option.
61 −t tagstring
63 See the ex command description of the −t option.
64 −w size See the ex command description of the −w option.
66
68 See the OPERANDS section of the ex command for a description of the op‐
69 erands supported by the vi command.
70
72 If standard input is not a terminal device, the results are undefined.
73 The standard input consists of a series of commands and input text, as
74 described in the EXTENDED DESCRIPTION section.
75 If a read from the standard input returns an error, or if the editor
77 detects an end-of-file condition from the standard input, it shall be
78 equivalent to a SIGHUP asynchronous event.
79
81 See the INPUT FILES section of the ex command for a description of the
82 input files supported by the vi command.
83
85 See the ENVIRONMENT VARIABLES section of the ex command for the envi‐
86 ronment variables that affect the execution of the vi command.
87
89 See the ASYNCHRONOUS EVENTS section of the ex for the asynchronous
90 events that affect the execution of the vi command.
91
93 If standard output is not a terminal device, undefined results occur.
94 Standard output may be used for writing prompts to the user, for infor‐
96 mational messages, and for writing lines from the file.
97
99 If standard output is not a terminal device, undefined results occur.
100 The standard error shall be used only for diagnostic messages.
102
104 See the OUTPUT FILES section of the ex command for a description of the
105 output files supported by the vi command.
106
108 If the terminal does not have the capabilities necessary to support an
109 unspecified portion of the vi definition, implementations shall start
110 initially in ex mode or open mode. Otherwise, after initialization, vi
111 shall be in command mode; text input mode can be entered by one of sev‐
112 eral commands used to insert or change text. In text input mode, <ESC>
113 can be used to return to command mode; other uses of <ESC> are
114 described later in this section; see Terminate Command or Input Mode.
115 Initialization in ex and vi
117 See Initialization in ex and vi for a description of ex and vi initial‐
118 ization for the vi utility.
119 Command Descriptions in vi
121 The following symbols are used in this reference page to represent
122 arguments to commands.
123 buffer See the description of buffer in the EXTENDED DESCRIPTION sec‐
125 tion of the ex utility; see Command Descriptions in ex.
126 In open and visual mode, when a command synopsis shows both
128 [buffer] and [count] preceding the command name, they can be
129 specified in either order.
130 count A positive integer used as an optional argument to most com‐
132 mands, either to give a repeat count or as a size. This argu‐
133 ment is optional and shall default to 1 unless otherwise speci‐
134 fied.
135 The Synopsis lines for the vi commands <control>‐G, <con‐
137 trol>‐L, <control>‐R, <control>‐], %, &, ^, D, m, M, Q, u, U,
138 and ZZ do not have count as an optional argument. Regardless,
139 it shall not be an error to specify a count to these commands,
140 and any specified count shall be ignored.
141 motion An optional trailing argument used by the !, <, >, c, d, and y
143 commands, which is used to indicate the region of text that
144 shall be affected by the command. The motion can be either one
145 of the command characters repeated or one of several other vi
146 commands (listed in the following table). Each of the applica‐
147 ble commands specifies the region of text matched by repeating
148 the command; each command that can be used as a motion command
149 specifies the region of text it affects.
150 Commands that take motion arguments operate on either lines or
152 characters, depending on the circumstances. When operating on
153 lines, all lines that fall partially or wholly within the text
154 region specified for the command shall be affected. When oper‐
155 ating on characters, only the exact characters in the specified
156 text region shall be affected. Each motion command specifies
157 this individually.
158 When commands that may be motion commands are not used as
160 motion commands, they shall set the current position to the
161 current line and column as specified.
162 The following commands shall be valid cursor motion commands:
164 <apostrophe> ( - j H
166 <carriage-return> ) $ k L
167 <comma> [[ % l M
168 <control>-H ]] _ n N
169 <control>-N { ; t T
170 <control>-P } ? w W
171 <grave-accent> ^ b B
172 <newline> + e E
173 <space> | f F
174 <zero> / h G
175 Any count that is specified to a command that has an associated
177 motion command shall be applied to the motion command. If a
178 count is applied to both the command and its associated motion
179 command, the effect shall be multiplicative.
180 The following symbols are used in this section to specify locations in
182 the edit buffer:
183 current character
185 The character that is currently indicated by the cursor.
186 end of a line
188 The point located between the last non-<newline> (if any) and
189 the terminating <newline> of a line. For an empty line, this
190 location coincides with the beginning of the line.
191 end of the edit buffer
193 The location corresponding to the end of the last line in the
194 edit buffer.
195 The following symbols are used in this section to specify command
197 actions:
198 bigword In the POSIX locale, vi shall recognize four kinds of bigwords:
200 1. A maximal sequence of non-<blank> characters preceded and
202 followed by <blank> characters or the beginning or end of a
203 line or the edit buffer
204 2. One or more sequential blank lines
206 3. The first character in the edit buffer
208 4. The last non-<newline> in the edit buffer
210 word In the POSIX locale, vi shall recognize five kinds of words:
212 1. A maximal sequence of letters, digits, and underscores,
214 delimited at both ends by:
215 -- Characters other than letters, digits, or underscores
217 -- The beginning or end of a line
219 -- The beginning or end of the edit buffer
221 2. A maximal sequence of characters other than letters, dig‐
223 its, underscores, or <blank> characters, delimited at both
224 ends by:
225 -- A letter, digit, underscore
227 -- <blank> characters
229 -- The beginning or end of a line
231 -- The beginning or end of the edit buffer
233 3. One or more sequential blank lines
235 4. The first character in the edit buffer
237 5. The last non-<newline> in the edit buffer
239 section boundary
241 A section boundary is one of the following:
242 1. A line whose first character is a <form-feed>
244 2. A line whose first character is an open curly brace ('{')
246 3. A line whose first character is a <period> and whose second
248 and third characters match a two-character pair in the sec‐
249 tions edit option (see ed)
250 4. A line whose first character is a <period> and whose only
252 other character matches the first character of a two-char‐
253 acter pair in the sections edit option, where the second
254 character of the two-character pair is a <space>
255 5. The first line of the edit buffer
257 6. The last line of the edit buffer if the last line of the
259 edit buffer is empty or if it is a ]] or } command; other‐
260 wise, the last non-<newline> of the last line of the edit
261 buffer
262 paragraph boundary
264 A paragraph boundary is one of the following:
265 1. A section boundary
267 2. A line whose first character is a <period> and whose second
269 and third characters match a two-character pair in the
270 paragraphs edit option (see ed)
271 3. A line whose first character is a <period> and whose only
273 other character matches the first character of a two-char‐
274 acter pair in the paragraphs edit option, where the second
275 character of the two-character pair is a <space>
276 4. One or more sequential blank lines
278 remembered search direction
280 See the description of remembered search direction in ed.
281 sentence boundary
283 A sentence boundary is one of the following:
284 1. A paragraph boundary
286 2. The first non-<blank> that occurs after a paragraph bound‐
288 ary
289 3. The first non-<blank> that occurs after a <period> ('.'),
291 <exclamation-mark> ('!'), or <question-mark> ('?'), fol‐
292 lowed by two <space> characters or the end of a line; any
293 number of closing parenthesis (')'), closing brackets
294 (']'), double-quote ('"'), or single-quote (<apostrophe>)
295 characters can appear between the punctuation mark and the
296 two <space> characters or end-of-line
297 In the remainder of the description of the vi utility, the term ``buf‐
299 fer line'' refers to a line in the edit buffer and the term ``display
300 line'' refers to the line or lines on the display screen used to dis‐
301 play one buffer line. The term ``current line'' refers to a specific
302 ``buffer line''.
303 If there are display lines on the screen for which there are no corre‐
305 sponding buffer lines because they correspond to lines that would be
306 after the end of the file, they shall be displayed as a single <tilde>
307 ('~') character, plus the terminating <newline>.
308 The last line of the screen shall be used to report errors or display
310 informational messages. It shall also be used to display the input for
311 ``line-oriented commands'' (/, ?, :, and !). When a line-oriented com‐
312 mand is executed, the editor shall enter text input mode on the last
313 line on the screen, using the respective command characters as prompt
314 characters. (In the case of the ! command, the associated motion shall
315 be entered by the user before the editor enters text input mode.) The
316 line entered by the user shall be terminated by a <newline>, a
317 non-<control>‐V-escaped <carriage-return>, or unescaped <ESC>. It is
318 unspecified if more characters than require a display width minus one
319 column number of screen columns can be entered.
320 If any command is executed that overwrites a portion of the screen
322 other than the last line of the screen (for example, the ex suspend or
323 ! commands), other than the ex shell command, the user shall be
324 prompted for a character before the screen is refreshed and the edit
325 session continued.
326 <tab> characters shall take up the number of columns on the screen set
328 by the tabstop edit option (see ed), unless there are less than that
329 number of columns before the display margin that will cause the dis‐
330 played line to be folded; in this case, they shall only take up the
331 number of columns up to that boundary.
332 The cursor shall be placed on the current line and relative to the cur‐
334 rent column as specified by each command described in the following
335 sections.
336 In open mode, if the current line is not already displayed, then it
338 shall be displayed.
339 In visual mode, if the current line is not displayed, then the lines
341 that are displayed shall be expanded, scrolled, or redrawn to cause an
342 unspecified portion of the current line to be displayed. If the screen
343 is redrawn, no more than the number of display lines specified by the
344 value of the window edit option shall be displayed (unless the current
345 line cannot be completely displayed in the number of display lines
346 specified by the window edit option) and the current line shall be
347 positioned as close to the center of the displayed lines as possible
348 (within the constraints imposed by the distance of the line from the
349 beginning or end of the edit buffer). If the current line is before the
350 first line in the display and the screen is scrolled, an unspecified
351 portion of the current line shall be placed on the first line of the
352 display. If the current line is after the last line in the display and
353 the screen is scrolled, an unspecified portion of the current line
354 shall be placed on the last line of the display.
355 In visual mode, if a line from the edit buffer (other than the current
357 line) does not entirely fit into the lines at the bottom of the display
358 that are available for its presentation, the editor may choose not to
359 display any portion of the line. The lines of the display that do not
360 contain text from the edit buffer for this reason shall each consist of
361 a single '@' character.
362 In visual mode, the editor may choose for unspecified reasons to not
364 update lines in the display to correspond to the underlying edit buffer
365 text. The lines of the display that do not correctly correspond to text
366 from the edit buffer for this reason shall consist of a single '@'
367 character (plus the terminating <newline>), and the <control>‐R command
368 shall cause the editor to update the screen to correctly represent the
369 edit buffer.
370 Open and visual mode commands that set the current column set it to a
372 column position in the display, and not a character position in the
373 line. In this case, however, the column position in the display shall
374 be calculated for an infinite width display; for example, the column
375 related to a character that is part of a line that has been folded onto
376 additional screen lines will be offset from the display line column
377 where the buffer line begins, not from the beginning of a particular
378 display line.
379 The display cursor column in the display is based on the value of the
381 current column, as follows, with each rule applied in turn:
382 1. If the current column is after the last display line column used by
384 the displayed line, the display cursor column shall be set to the
385 last display line column occupied by the last non-<newline> in the
386 current line; otherwise, the display cursor column shall be set to
387 the current column.
388 2. If the character of which some portion is displayed in the display
390 line column specified by the display cursor column requires more
391 than a single display line column:
392 a. If in text input mode, the display cursor column shall be
394 adjusted to the first display line column in which any portion
395 of that character is displayed.
396 b. Otherwise, the display cursor column shall be adjusted to the
398 last display line column in which any portion of that character
399 is displayed.
400 The current column shall not be changed by these adjustments to the
402 display cursor column.
403 If an error occurs during the parsing or execution of a vi command:
405 * The terminal shall be alerted. Execution of the vi command shall
407 stop, and the cursor (for example, the current line and column)
408 shall not be further modified.
409 * Unless otherwise specified by the following command sections, it is
411 unspecified whether an informational message shall be displayed.
412 * Any partially entered vi command shall be discarded.
414 * If the vi command resulted from a map expansion, all characters
416 from that map expansion shall be discarded, except as otherwise
417 specified by the map command (see ed).
418 * If the vi command resulted from the execution of a buffer, no fur‐
420 ther commands caused by the execution of the buffer shall be exe‐
421 cuted.
422 Page Backwards
424 Synopsis:
425 [count] <control>-B
426 If in open mode, the <control>‐B command shall behave identically to
428 the z command. Otherwise, if the current line is the first line of the
429 edit buffer, it shall be an error.
430 If the window edit option is less than 3, display a screen where the
432 last line of the display shall be some portion of:
433 (current first line) −1
435 otherwise, display a screen where the first line of the display shall
437 be some portion of:
438 (current first line) − count x ((window edit option) −2)
440 If this calculation would result in a line that is before the first
442 line of the edit buffer, the first line of the display shall display
443 some portion of the first line of the edit buffer.
444 Current line: If no lines from the previous display remain on the
446 screen, set to the last line of the display; otherwise, set to (line −
447 the number of new lines displayed on this screen).
448 Current column: Set to non-<blank>.
450 Scroll Forward
452 Synopsis:
453 [count] <control>-D
454 If the current line is the last line of the edit buffer, it shall be an
456 error.
457 If no count is specified, count shall default to the count associated
459 with the previous <control>‐D or <control>‐U command. If there was no
460 previous <control>‐D or <control>‐U command, count shall default to the
461 value of the scroll edit option.
462 If in open mode, write lines starting with the line after the current
464 line, until count lines or the last line of the file have been written.
465 Current line: If the current line + count is past the last line of the
467 edit buffer, set to the last line of the edit buffer; otherwise, set to
468 the current line + count.
469 Current column: Set to non-<blank>.
471 Scroll Forward by Line
473 Synopsis:
474 [count] <control>-E
475 Display the line count lines after the last line currently displayed.
477 If the last line of the edit buffer is displayed, it shall be an error.
479 If there is no line count lines after the last line currently dis‐
480 played, the last line of the display shall display some portion of the
481 last line of the edit buffer.
482 Current line: Unchanged if the previous current character is displayed;
484 otherwise, set to the first line displayed.
485 Current column: Unchanged.
487 Page Forward
489 Synopsis:
490 [count] <control>-F
491 If in open mode, the <control>‐F command shall behave identically to
493 the z command. Otherwise, if the current line is the last line of the
494 edit buffer, it shall be an error.
495 If the window edit option is less than 3, display a screen where the
497 first line of the display shall be some portion of:
498 (current last line) +1
500 otherwise, display a screen where the first line of the display shall
502 be some portion of:
503 (current first line) + count x ((window edit option) −2)
505 If this calculation would result in a line that is after the last line
507 of the edit buffer, the last line of the display shall display some
508 portion of the last line of the edit buffer.
509 Current line: If no lines from the previous display remain on the
511 screen, set to the first line of the display; otherwise, set to (line +
512 the number of new lines displayed on this screen).
513 Current column: Set to non-<blank>.
515 Display Information
517 Synopsis:
518 <control>-G
519 This command shall be equivalent to the ex file command.
521 Move Cursor Backwards
523 Synopsis:
524 [count] <control>-H
525 [count] h
526 the current erase character (see stty)
527 If there are no characters before the current character on the current
529 line, it shall be an error. If there are less than count previous char‐
530 acters on the current line, count shall be adjusted to the number of
531 previous characters on the line.
532 If used as a motion command:
534 1. The text region shall be from the character before the starting
536 cursor up to and including the countth character before the start‐
537 ing cursor.
538 2. Any text copied to a buffer shall be in character mode.
540 If not used as a motion command:
542 Current line: Unchanged.
544 Current column: Set to (column − the number of columns occupied by
546 count characters ending with the previous current column).
547 Move Down
549 Synopsis:
550 [count] <newline>
551 [count] <control>-J
552 [count] <control>-M
553 [count] <control>-N
554 [count] j
555 [count] <carriage-return>
556 [count] +
557 If there are less than count lines after the current line in the edit
559 buffer, it shall be an error.
560 If used as a motion command:
562 1. The text region shall include the starting line and the next count
564 − 1 lines.
565 2. Any text copied to a buffer shall be in line mode.
567 If not used as a motion command:
569 Current line: Set to current line+ count.
571 Current column: Set to non-<blank> for the <carriage-return>, <con‐
573 trol>‐M, and + commands; otherwise, unchanged.
574 Clear and Redisplay
576 Synopsis:
577 <control>-L
578 If in open mode, clear the screen and redisplay the current line. Oth‐
580 erwise, clear and redisplay the screen.
581 Current line: Unchanged.
583 Current column: Unchanged.
585 Move Up
587 Synopsis:
588 [count] <control>-P
589 [count] k
590 [count] −
591 If there are less than count lines before the current line in the edit
593 buffer, it shall be an error.
594 If used as a motion command:
596 1. The text region shall include the starting line and the previous
598 count lines.
599 2. Any text copied to a buffer shall be in line mode.
601 If not used as a motion command:
603 Current line: Set to current line − count.
605 Current column: Set to non-<blank> for the − command; otherwise,
607 unchanged.
608 Redraw Screen
610 Synopsis:
611 <control>-R
612 If any lines have been deleted from the display screen and flagged as
614 deleted on the terminal using the @ convention (see the beginning of
615 the EXTENDED DESCRIPTION section), they shall be redisplayed to match
616 the contents of the edit buffer.
617 It is unspecified whether lines flagged with @ because they do not fit
619 on the terminal display shall be affected.
620 Current line: Unchanged.
622 Current column: Unchanged.
624 Scroll Backward
626 Synopsis:
627 [count] <control>-U
628 If the current line is the first line of the edit buffer, it shall be
630 an error.
631 If no count is specified, count shall default to the count associated
633 with the previous <control>‐D or <control>‐U command. If there was no
634 previous <control>‐D or <control>‐U command, count shall default to the
635 value of the scroll edit option.
636 Current line: If count is greater than the current line, set to 1; oth‐
638 erwise, set to the current line − count.
639 Current column: Set to non-<blank>.
641 Scroll Backward by Line
643 Synopsis:
644 [count] <control>-Y
645 Display the line count lines before the first line currently displayed.
647 If the current line is the first line of the edit buffer, it shall be
649 an error. If this calculation would result in a line that is before the
650 first line of the edit buffer, the first line of the display shall dis‐
651 play some portion of the first line of the edit buffer.
652 Current line: Unchanged if the previous current character is displayed;
654 otherwise, set to the first line displayed.
655 Current column: Unchanged.
657 Edit the Alternate File
659 Synopsis:
660 <control>-^
661 This command shall be equivalent to the ex edit command, with the
663 alternate pathname as its argument.
664 Terminate Command or Input Mode
666 Synopsis:
667 <ESC>
668 If a partial vi command (as defined by at least one, non-count charac‐
670 ter) has been entered, discard the count and the command character(s).
671 Otherwise, if no command characters have been entered, and the <ESC>
673 was the result of a map expansion, the terminal shall be alerted and
674 the <ESC> character shall be discarded, but it shall not be an error.
675 Otherwise, it shall be an error.
677 Current line: Unchanged.
679 Current column: Unchanged.
681 Search for tagstring
683 Synopsis:
684 <control>-]
685 If the current character is not a word or <blank>, it shall be an
687 error.
688 This command shall be equivalent to the ex tag command, with the argu‐
690 ment to that command defined as follows.
691 If the current character is a <blank>:
693 1. Skip all <blank> characters after the cursor up to the end of the
695 line.
696 2. If the end of the line is reached, it shall be an error.
698 Then, the argument to the ex tag command shall be the current character
700 and all subsequent characters, up to the first non-word character or
701 the end of the line.
702 Move Cursor Forward
704 Synopsis:
705 [count] <space>
706 [count] l (ell)
707 If there are less than count non-<newline> characters after the cursor
709 on the current line, count shall be adjusted to the number of non-<new‐
710 line> characters after the cursor on the line.
711 If used as a motion command:
713 1. If the current or countth character after the cursor is the last
715 non-<newline> in the line, the text region shall be comprised of
716 the current character up to and including the last non-<newline> in
717 the line. Otherwise, the text region shall be from the current
718 character up to, but not including, the countth character after the
719 cursor.
720 2. Any text copied to a buffer shall be in character mode.
722 If not used as a motion command:
724 If there are no non-<newline> characters after the current character on
726 the current line, it shall be an error.
727 Current line: Unchanged.
729 Current column: Set to the last column that displays any portion of the
731 countth character after the current character.
732 Replace Text with Results from Shell Command
734 Synopsis:
735 [count] ! motion shell-commands <newline>
736 If the motion command is the ! command repeated:
738 1. If the edit buffer is empty and no count was supplied, the command
740 shall be the equivalent of the ex :read ! command, with the text
741 input, and no text shall be copied to any buffer.
742 2. Otherwise:
744 a. If there are less than count −1 lines after the current line in
746 the edit buffer, it shall be an error.
747 b. The text region shall be from the current line up to and
749 including the next count −1 lines.
750 Otherwise, the text region shall be the lines in which any character of
752 the text region specified by the motion command appear.
753 Any text copied to a buffer shall be in line mode.
755 This command shall be equivalent to the ex ! command for the specified
757 lines.
758 Move Cursor to End-of-Line
760 Synopsis:
761 [count] $
762 It shall be an error if there are less than (count −1) lines after the
764 current line in the edit buffer.
765 If used as a motion command:
767 1. If count is 1:
769 a. It shall be an error if the line is empty.
771 b. Otherwise, the text region shall consist of all characters from
773 the starting cursor to the last non-<newline> in the line,
774 inclusive, and any text copied to a buffer shall be in charac‐
775 ter mode.
776 2. Otherwise, if the starting cursor position is at or before the
778 first non-<blank> in the line, the text region shall consist of the
779 current and the next count −1 lines, and any text saved to a buffer
780 shall be in line mode.
781 3. Otherwise, the text region shall consist of all characters from the
783 starting cursor to the last non-<newline> in the line that is count
784 −1 lines forward from the current line, and any text copied to a
785 buffer shall be in character mode.
786 If not used as a motion command:
788 Current line: Set to the current line + count−1.
790 Current column: The current column is set to the last display line col‐
792 umn of the last non-<newline> in the line, or column position 1 if the
793 line is empty.
794 The current column shall be adjusted to be on the last display line
796 column of the last non-<newline> of the current line as subsequent com‐
797 mands change the current line, until a command changes the current col‐
798 umn.
799 Move to Matching Character
801 Synopsis:
802 %
803 If the character at the current position is not a parenthesis, bracket,
805 or curly brace, search forward in the line to the first one of those
806 characters. If no such character is found, it shall be an error.
807 The matching character shall be the parenthesis, bracket, or curly
809 brace matching the parenthesis, bracket, or curly brace, respectively,
810 that was at the current position or that was found on the current line.
811 Matching shall be determined as follows, for an open parenthesis:
813 1. Set a counter to 1.
815 2. Search forwards until a parenthesis is found or the end of the edit
817 buffer is reached.
818 3. If the end of the edit buffer is reached, it shall be an error.
820 4. If an open parenthesis is found, increment the counter by 1.
822 5. If a close parenthesis is found, decrement the counter by 1.
824 6. If the counter is zero, the current character is the matching char‐
826 acter.
827 Matching for a close parenthesis shall be equivalent, except that the
829 search shall be backwards, from the starting character to the beginning
830 of the buffer, a close parenthesis shall increment the counter by 1,
831 and an open parenthesis shall decrement the counter by 1.
832 Matching for brackets and curly braces shall be equivalent, except that
834 searching shall be done for open and close brackets or open and close
835 curly braces. It is implementation-defined whether other characters are
836 searched for and matched as well.
837 If used as a motion command:
839 1. If the matching cursor was after the starting cursor in the edit
841 buffer, and the starting cursor position was at or before the first
842 non-<blank> non-<newline> in the starting line, and the matching
843 cursor position was at or after the last non-<blank> non-<newline>
844 in the matching line, the text region shall consist of the current
845 line to the matching line, inclusive, and any text copied to a buf‐
846 fer shall be in line mode.
847 2. If the matching cursor was before the starting cursor in the edit
849 buffer, and the starting cursor position was at or after the last
850 non-<blank> non-<newline> in the starting line, and the matching
851 cursor position was at or before the first non-<blank> non-<new‐
852 line> in the matching line, the text region shall consist of the
853 current line to the matching line, inclusive, and any text copied
854 to a buffer shall be in line mode.
855 3. Otherwise, the text region shall consist of the starting character
857 to the matching character, inclusive, and any text copied to a buf‐
858 fer shall be in character mode.
859 If not used as a motion command:
861 Current line: Set to the line where the matching character is located.
863 Current column: Set to the last column where any portion of the match‐
865 ing character is displayed.
866 Repeat Substitution
868 Synopsis:
869 &
870 Repeat the previous substitution command. This command shall be equiva‐
872 lent to the ex & command with the current line as its addresses, and
873 without options, count, or flags.
874 Return to Previous Context at Beginning of Line
876 Synopsis:
877 ' character
878 It shall be an error if there is no line in the edit buffer marked by
880 character.
881 If used as a motion command:
883 1. If the starting cursor is after the marked cursor, then the loca‐
885 tions of the starting cursor and the marked cursor in the edit buf‐
886 fer shall be logically swapped.
887 2. The text region shall consist of the starting line up to and
889 including the marked line, and any text copied to a buffer shall be
890 in line mode.
891 If not used as a motion command:
893 Current line: Set to the line referenced by the mark.
895 Current column: Set to non-<blank>.
897 Return to Previous Context
899 Synopsis:
900 ` character
901 It shall be an error if the marked line is no longer in the edit buf‐
903 fer. If the marked line no longer contains a character in the saved
904 numbered character position, it shall be as if the marked position is
905 the first non-<blank>.
906 If used as a motion command:
908 1. It shall be an error if the marked cursor references the same char‐
910 acter in the edit buffer as the starting cursor.
911 2. If the starting cursor is after the marked cursor, then the loca‐
913 tions of the starting cursor and the marked cursor in the edit buf‐
914 fer shall be logically swapped.
915 3. If the starting line is empty or the starting cursor is at or
917 before the first non-<blank> non-<newline> of the starting line,
918 and the marked cursor line is empty or the marked cursor references
919 the first character of the marked cursor line, the text region
920 shall consist of all lines containing characters from the starting
921 cursor to the line before the marked cursor line, inclusive, and
922 any text copied to a buffer shall be in line mode.
923 4. Otherwise, if the marked cursor line is empty or the marked cursor
925 references a character at or before the first non-<blank> non-<new‐
926 line> of the marked cursor line, the region of text shall be from
927 the starting cursor to the last non-<newline> of the line before
928 the marked cursor line, inclusive, and any text copied to a buffer
929 shall be in character mode.
930 5. Otherwise, the region of text shall be from the starting cursor
932 (inclusive), to the marked cursor (exclusive), and any text copied
933 to a buffer shall be in character mode.
934 If not used as a motion command:
936 Current line: Set to the line referenced by the mark.
938 Current column: Set to the last column in which any portion of the
940 character referenced by the mark is displayed.
941 Return to Previous Section
943 Synopsis:
944 [count] [[
945 Move the cursor backward through the edit buffer to the first character
947 of the previous section boundary, count times.
948 If used as a motion command:
950 1. If the starting cursor was at the first character of the starting
952 line or the starting line was empty, and the first character of the
953 boundary was the first character of the boundary line, the text
954 region shall consist of the current line up to and including the
955 line where the countth next boundary starts, and any text copied to
956 a buffer shall be in line mode.
957 2. If the boundary was the last line of the edit buffer or the last
959 non-<newline> of the last line of the edit buffer, the text region
960 shall consist of the last character in the edit buffer up to and
961 including the starting character, and any text saved to a buffer
962 shall be in character mode.
963 3. Otherwise, the text region shall consist of the starting character
965 up to but not including the first character in the countth next
966 boundary, and any text copied to a buffer shall be in character
967 mode.
968 If not used as a motion command:
970 Current line: Set to the line where the countth next boundary in the
972 edit buffer starts.
973 Current column: Set to the last column in which any portion of the
975 first character of the countth next boundary is displayed, or column
976 position 1 if the line is empty.
977 Move to Next Section
979 Synopsis:
980 [count] ]]
981 Move the cursor forward through the edit buffer to the first character
983 of the next section boundary, count times.
984 If used as a motion command:
986 1. If the starting cursor was at the first character of the starting
988 line or the starting line was empty, and the first character of the
989 boundary was the first character of the boundary line, the text
990 region shall consist of the current line up to and including the
991 line where the countth previous boundary starts, and any text
992 copied to a buffer shall be in line mode.
993 2. If the boundary was the first line of the edit buffer, the text
995 region shall consist of the first character in the edit buffer up
996 to but not including the starting character, and any text copied to
997 a buffer shall be in character mode.
998 3. Otherwise, the text region shall consist of the first character in
1000 the countth previous section boundary up to but not including the
1001 starting character, and any text copied to a buffer shall be in
1002 character mode.
1003 If not used as a motion command:
1005 Current line: Set to the line where the countth previous boundary in
1007 the edit buffer starts.
1008 Current column: Set to the last column in which any portion of the
1010 first character of the countth previous boundary is displayed, or col‐
1011 umn position 1 if the line is empty.
1012 Move to First Non-<blank> Position on Current Line
1014 Synopsis:
1015 ^
1016 If used as a motion command:
1018 1. If the line has no non-<blank> non-<newline> characters, or if the
1020 cursor is at the first non-<blank> non-<newline> of the line, it
1021 shall be an error.
1022 2. If the cursor is before the first non-<blank> non-<newline> of the
1024 line, the text region shall be comprised of the current character,
1025 up to, but not including, the first non-<blank> non-<newline> of
1026 the line.
1027 3. If the cursor is after the first non-<blank> non-<newline> of the
1029 line, the text region shall be from the character before the start‐
1030 ing cursor up to and including the first non-<blank> non-<newline>
1031 of the line.
1032 4. Any text copied to a buffer shall be in character mode.
1034 If not used as a motion command:
1036 Current line: Unchanged.
1038 Current column: Set to non-<blank>.
1040 Current and Line Above
1042 Synopsis:
1043 [count] _
1044 If there are less than count −1 lines after the current line in the
1046 edit buffer, it shall be an error.
1047 If used as a motion command:
1049 1. If count is less than 2, the text region shall be the current line.
1051 2. Otherwise, the text region shall include the starting line and the
1053 next count −1 lines.
1054 3. Any text copied to a buffer shall be in line mode.
1056 If not used as a motion command:
1058 Current line: Set to current line + count −1.
1060 Current column: Set to non-<blank>.
1062 Move Back to Beginning of Sentence
1064 Synopsis:
1065 [count] (
1066 Move backward to the beginning of a sentence. This command shall be
1068 equivalent to the [[ command, with the exception that sentence bound‐
1069 aries shall be used instead of section boundaries.
1070 Move Forward to Beginning of Sentence
1072 Synopsis:
1073 [count] )
1074 Move forward to the beginning of a sentence. This command shall be
1076 equivalent to the ]] command, with the exception that sentence bound‐
1077 aries shall be used instead of section boundaries.
1078 Move Back to Preceding Paragraph
1080 Synopsis:
1081 [count] {
1082 Move back to the beginning of the preceding paragraph. This command
1084 shall be equivalent to the [[ command, with the exception that para‐
1085 graph boundaries shall be used instead of section boundaries.
1086 Move Forward to Next Paragraph
1088 Synopsis:
1089 [count] }
1090 Move forward to the beginning of the next paragraph. This command shall
1092 be equivalent to the ]] command, with the exception that paragraph
1093 boundaries shall be used instead of section boundaries.
1094 Move to Specific Column Position
1096 Synopsis:
1097 [count] |
1098 For the purposes of this command, lines that are too long for the cur‐
1100 rent display and that have been folded shall be treated as having a
1101 single, 1−based, number of columns.
1102 If there are less than count columns in which characters from the cur‐
1104 rent line are displayed on the screen, count shall be adjusted to be
1105 the last column in which any portion of the line is displayed on the
1106 screen.
1107 If used as a motion command:
1109 1. If the line is empty, or the cursor character is the same as the
1111 character on the countth column of the line, it shall be an error.
1112 2. If the cursor is before the countth column of the line, the text
1114 region shall be comprised of the current character, up to but not
1115 including the character on the countth column of the line.
1116 3. If the cursor is after the countth column of the line, the text
1118 region shall be from the character before the starting cursor up to
1119 and including the character on the countth column of the line.
1120 4. Any text copied to a buffer shall be in character mode.
1122 If not used as a motion command:
1124 Current line: Unchanged.
1126 Current column: Set to the last column in which any portion of the
1128 character that is displayed in the count column of the line is dis‐
1129 played.
1130 Reverse Find Character
1132 Synopsis:
1133 [count] ,
1134 If the last F, f, T, or t command was F, f, T, or t, this command shall
1136 be equivalent to an f, F, t, or T command, respectively, with the spec‐
1137 ified count and the same search character.
1138 If there was no previous F, f, T, or t command, it shall be an error.
1140 Repeat
1142 Synopsis:
1143 [count] .
1144 Repeat the last !, <, >, A, C, D, I, J, O, P, R, S, X, Y, a, c, d, i,
1146 o, p, r, s, x, y, or ~ command. It shall be an error if none of these
1147 commands have been executed. Commands (other than commands that enter
1148 text input mode) executed as a result of map expansions, shall not
1149 change the value of the last repeatable command.
1150 Repeated commands with associated motion commands shall repeat the
1152 motion command as well; however, any specified count shall replace the
1153 count(s) that were originally specified to the repeated command or its
1154 associated motion command.
1155 If the motion component of the repeated command is f, F, t, or T, the
1157 repeated command shall not set the remembered search character for the
1158 ; and , commands.
1159 If the repeated command is p or P, and the buffer associated with that
1161 command was a numeric buffer named with a number less than 9, the buf‐
1162 fer associated with the repeated command shall be set to be the buffer
1163 named by the name of the previous buffer logically incremented by 1.
1164 If the repeated character is a text input command, the input text asso‐
1166 ciated with that command is repeated literally:
1167 * Input characters are neither macro or abbreviation-expanded.
1169 * Input characters are not interpreted in any special way with the
1171 exception that <newline>, <carriage-return>, and <control>‐T behave
1172 as described in Input Mode Commands in vi.
1173 Current line: Set as described for the repeated command.
1175 Current column: Set as described for the repeated command.
1177 Find Regular Expression
1179 Synopsis:
1180 /
1181 If the input line contains no non-<newline> characters, it shall be
1183 equivalent to a line containing only the last regular expression
1184 encountered. The enhanced regular expressions supported by vi are
1185 described in Regular Expressions in ex.
1186 Otherwise, the line shall be interpreted as one or more regular expres‐
1188 sions, optionally followed by an address offset or a vi z command.
1189 If the regular expression is not the last regular expression on the
1191 line, or if a line offset or z command is specified, the regular
1192 expression shall be terminated by an unescaped '/' character, which
1193 shall not be used as part of the regular expression. If the regular
1194 expression is not the first regular expression on the line, it shall be
1195 preceded by zero or more <blank> characters, a <semicolon>, zero or
1196 more <blank> characters, and a leading '/' character, which shall not
1197 be interpreted as part of the regular expression. It shall be an error
1198 to precede any regular expression with any characters other than these.
1199 Each search shall begin from the character after the first character of
1201 the last match (or, if it is the first search, after the cursor). If
1202 the wrapscan edit option is set, the search shall continue to the char‐
1203 acter before the starting cursor character; otherwise, to the end of
1204 the edit buffer. It shall be an error if any search fails to find a
1205 match, and an informational message to this effect shall be displayed.
1206 An optional address offset (see Addressing in ex) can be specified
1208 after the last regular expression by including a trailing '/' character
1209 after the regular expression and specifying the address offset. This
1210 offset will be from the line containing the match for the last regular
1211 expression specified. It shall be an error if the line offset would
1212 indicate a line address less than 1 or greater than the last line in
1213 the edit buffer. An address offset of zero shall be supported. It shall
1214 be an error to follow the address offset with any other characters than
1215 <blank> characters.
1216 If not used as a motion command, an optional z command (see Redraw Win‐
1218 dow) can be specified after the last regular expression by including a
1219 trailing '/' character after the regular expression, zero or more
1220 <blank> characters, a 'z', zero or more <blank> characters, an optional
1221 new window edit option value, zero or more <blank> characters, and a
1222 location character. The effect shall be as if the z command was exe‐
1223 cuted after the / command. It shall be an error to follow the z command
1224 with any other characters than <blank> characters.
1225 The remembered search direction shall be set to forward.
1227 If used as a motion command:
1229 1. It shall be an error if the last match references the same charac‐
1231 ter in the edit buffer as the starting cursor.
1232 2. If any address offset is specified, the last match shall be
1234 adjusted by the specified offset as described previously.
1235 3. If the starting cursor is after the last match, then the locations
1237 of the starting cursor and the last match in the edit buffer shall
1238 be logically swapped.
1239 4. If any address offset is specified, the text region shall consist
1241 of all lines containing characters from the starting cursor to the
1242 last match line, inclusive, and any text copied to a buffer shall
1243 be in line mode.
1244 5. Otherwise, if the starting line is empty or the starting cursor is
1246 at or before the first non-<blank> non-<newline> of the starting
1247 line, and the last match line is empty or the last match starts at
1248 the first character of the last match line, the text region shall
1249 consist of all lines containing characters from the starting cursor
1250 to the line before the last match line, inclusive, and any text
1251 copied to a buffer shall be in line mode.
1252 6. Otherwise, if the last match line is empty or the last match begins
1254 at a character at or before the first non-<blank> non-<newline> of
1255 the last match line, the region of text shall be from the current
1256 cursor to the last non-<newline> of the line before the last match
1257 line, inclusive, and any text copied to a buffer shall be in char‐
1258 acter mode.
1259 7. Otherwise, the region of text shall be from the current cursor
1261 (inclusive), to the first character of the last match (exclusive),
1262 and any text copied to a buffer shall be in character mode.
1263 If not used as a motion command:
1265 Current line: If a match is found, set to the last matched line plus
1267 the address offset, if any; otherwise, unchanged.
1268 Current column: Set to the last column on which any portion of the
1270 first character in the last matched string is displayed, if a match is
1271 found; otherwise, unchanged.
1272 Move to First Character in Line
1274 Synopsis:
1275 0 (zero)
1276 Move to the first character on the current line. The character '0'
1278 shall not be interpreted as a command if it is immediately preceded by
1279 a digit.
1280 If used as a motion command:
1282 1. If the cursor character is the first character in the line, it
1284 shall be an error.
1285 2. The text region shall be from the character before the cursor char‐
1287 acter up to and including the first character in the line.
1288 3. Any text copied to a buffer shall be in character mode.
1290 If not used as a motion command:
1292 Current line: Unchanged.
1294 Current column: The last column in which any portion of the first char‐
1296 acter in the line is displayed, or if the line is empty, unchanged.
1297 Execute an ex Command
1299 Synopsis:
1300 :
1301 Execute one or more ex commands.
1303 If any portion of the screen other than the last line of the screen was
1305 overwritten by any ex command (except shell), vi shall display a mes‐
1306 sage indicating that it is waiting for an input from the user, and
1307 shall then read a character. This action may also be taken for other,
1308 unspecified reasons.
1309 If the next character entered is a ':', another ex command shall be
1311 accepted and executed. Any other character shall cause the screen to be
1312 refreshed and vi shall return to command mode.
1313 Current line: As specified for the ex command.
1315 Current column: As specified for the ex command.
1317 Repeat Find
1319 Synopsis:
1320 [count] ;
1321 This command shall be equivalent to the last F, f, T, or t command,
1323 with the specified count, and with the same search character used for
1324 the last F, f, T, or t command. If there was no previous F, f, T, or t
1325 command, it shall be an error.
1326 Shift Left
1328 Synopsis:
1329 [count] < motion
1330 If the motion command is the < command repeated:
1332 1. If there are less than count −1 lines after the current line in the
1334 edit buffer, it shall be an error.
1335 2. The text region shall be from the current line, up to and including
1337 the next count −1 lines.
1338 Shift any line in the text region specified by the count and motion
1340 command one shiftwidth (see the ex shiftwidth option) toward the start
1341 of the line, as described by the ex < command. The unshifted lines
1342 shall be copied to the unnamed buffer in line mode.
1343 Current line: If the motion was from the current cursor position toward
1345 the end of the edit buffer, unchanged. Otherwise, set to the first line
1346 in the edit buffer that is part of the text region specified by the
1347 motion command.
1348 Current column: Set to non-<blank>.
1350 Shift Right
1352 Synopsis:
1353 [count] > motion
1354 If the motion command is the > command repeated:
1356 1. If there are less than count −1 lines after the current line in the
1358 edit buffer, it shall be an error.
1359 2. The text region shall be from the current line, up to and including
1361 the next count −1 lines.
1362 Shift any line with characters in the text region specified by the
1364 count and motion command one shiftwidth (see the ex shiftwidth option)
1365 away from the start of the line, as described by the ex > command. The
1366 unshifted lines shall be copied into the unnamed buffer in line mode.
1367 Current line: If the motion was from the current cursor position toward
1369 the end of the edit buffer, unchanged. Otherwise, set to the first line
1370 in the edit buffer that is part of the text region specified by the
1371 motion command.
1372 Current column: Set to non-<blank>.
1374 Scan Backwards for Regular Expression
1376 Synopsis:
1377 ?
1378 Scan backwards; the ? command shall be equivalent to the / command
1380 (see Find Regular Expression) with the following exceptions:
1381 1. The input prompt shall be a '?'.
1383 2. Each search shall begin from the character before the first charac‐
1385 ter of the last match (or, if it is the first search, the character
1386 before the cursor character).
1387 3. The search direction shall be from the cursor toward the beginning
1389 of the edit buffer, and the wrapscan edit option shall affect
1390 whether the search wraps to the end of the edit buffer and contin‐
1391 ues.
1392 4. The remembered search direction shall be set to backward.
1394 Execute
1396 Synopsis:
1397 @buffer
1398 If the buffer is specified as @, the last buffer executed shall be
1400 used. If no previous buffer has been executed, it shall be an error.
1401 Behave as if the contents of the named buffer were entered as standard
1403 input. After each line of a line-mode buffer, and all but the last line
1404 of a character mode buffer, behave as if a <newline> were entered as
1405 standard input.
1406 If an error occurs during this process, an error message shall be writ‐
1408 ten, and no more characters resulting from the execution of this com‐
1409 mand shall be processed.
1410 If a count is specified, behave as if that count were entered as user
1412 input before the characters from the @ buffer were entered.
1413 Current line: As specified for the individual commands.
1415 Current column: As specified for the individual commands.
1417 Reverse Case
1419 Synopsis:
1420 [count] ~
1421 Reverse the case of the current character and the next count −1 charac‐
1423 ters, such that lowercase characters that have uppercase counterparts
1424 shall be changed to uppercase characters, and uppercase characters that
1425 have lowercase counterparts shall be changed to lowercase characters,
1426 as prescribed by the current locale. No other characters shall be
1427 affected by this command.
1428 If there are less than count −1 characters after the cursor in the edit
1430 buffer, count shall be adjusted to the number of characters after the
1431 cursor in the edit buffer minus 1.
1432 For the purposes of this command, the next character after the last
1434 non-<newline> on the line shall be the next character in the edit buf‐
1435 fer.
1436 Current line: Set to the line including the (count−1)th character after
1438 the cursor.
1439 Current column: Set to the last column in which any portion of the
1441 (count−1)th character after the cursor is displayed.
1442 Append
1444 Synopsis:
1445 [count] a
1446 Enter text input mode after the current cursor position. No characters
1448 already in the edit buffer shall be affected by this command. A count
1449 shall cause the input text to be appended count −1 more times to the
1450 end of the input.
1451 Current line/column: As specified for the text input commands (see
1453 Input Mode Commands in vi).
1454 Append at End-of-Line
1456 Synopsis:
1457 [count] A
1458 This command shall be equivalent to the vi command:
1460 $ [ count ] a
1462 (see Append).
1464 Move Backward to Preceding Word
1466 Synopsis:
1467 [count] b
1468 With the exception that words are used as the delimiter instead of big‐
1470 words, this command shall be equivalent to the B command.
1471 Move Backward to Preceding Bigword
1473 Synopsis:
1474 [count] B
1475 If the edit buffer is empty or the cursor is on the first character of
1477 the edit buffer, it shall be an error. If less than count bigwords
1478 begin between the cursor and the start of the edit buffer, count shall
1479 be adjusted to the number of bigword beginnings between the cursor and
1480 the start of the edit buffer.
1481 If used as a motion command:
1483 1. The text region shall be from the first character of the countth
1485 previous bigword beginning up to but not including the cursor char‐
1486 acter.
1487 2. Any text copied to a buffer shall be in character mode.
1489 If not used as a motion command:
1491 Current line: Set to the line containing the current column.
1493 Current column: Set to the last column upon which any part of the first
1495 character of the countth previous bigword is displayed.
1496 Change
1498 Synopsis:
1499 [buffer][count] c motion
1500 If the motion command is the c command repeated:
1502 1. The buffer text shall be in line mode.
1504 2. If there are less than count −1 lines after the current line in the
1506 edit buffer, it shall be an error.
1507 3. The text region shall be from the current line up to and including
1509 the next count −1 lines.
1510 Otherwise, the buffer text mode and text region shall be as specified
1512 by the motion command.
1513 The replaced text shall be copied into buffer, if specified, and into
1515 the unnamed buffer. If the text to be replaced contains characters from
1516 more than a single line, or the buffer text is in line mode, the
1517 replaced text shall be copied into the numeric buffers as well.
1518 If the buffer text is in line mode:
1520 1. Any lines that contain characters in the region shall be deleted,
1522 and the editor shall enter text input mode at the beginning of a
1523 new line which shall replace the first line deleted.
1524 2. If the autoindent edit option is set, autoindent characters equal
1526 to the autoindent characters on the first line deleted shall be
1527 inserted as if entered by the user.
1528 Otherwise, if characters from more than one line are in the region of
1530 text:
1531 1. The text shall be deleted.
1533 2. Any text remaining in the last line in the text region shall be
1535 appended to the first line in the region, and the last line in the
1536 region shall be deleted.
1537 3. The editor shall enter text input mode after the last character not
1539 deleted from the first line in the text region, if any; otherwise,
1540 on the first column of the first line in the region.
1541 Otherwise:
1543 1. If the glyph for '$' is smaller than the region, the end of the
1545 region shall be marked with a '$'.
1546 2. The editor shall enter text input mode, overwriting the region of
1548 text.
1549 Current line/column: As specified for the text input commands (see
1551 Input Mode Commands in vi).
1552 Change to End-of-Line
1554 Synopsis:
1555 [buffer][count] C
1556 This command shall be equivalent to the vi command:
1558 [buffer][count] c$
1560 See the c command.
1562 Delete
1564 Synopsis:
1565 [buffer][count] d motion
1566 If the motion command is the d command repeated:
1568 1. The buffer text shall be in line mode.
1570 2. If there are less than count −1 lines after the current line in the
1572 edit buffer, it shall be an error.
1573 3. The text region shall be from the current line up to and including
1575 the next count −1 lines.
1576 Otherwise, the buffer text mode and text region shall be as specified
1578 by the motion command.
1579 If in open mode, and the current line is deleted, and the line remains
1581 on the display, an '@' character shall be displayed as the first glyph
1582 of that line.
1583 Delete the region of text into buffer, if specified, and into the
1585 unnamed buffer. If the text to be deleted contains characters from more
1586 than a single line, or the buffer text is in line mode, the deleted
1587 text shall be copied into the numeric buffers, as well.
1588 Current line: Set to the first text region line that appears in the
1590 edit buffer, unless that line has been deleted, in which case it shall
1591 be set to the last line in the edit buffer, or line 1 if the edit buf‐
1592 fer is empty.
1593 Current column:
1595 1. If the line is empty, set to column position 1.
1597 2. Otherwise, if the buffer text is in line mode or the motion was
1599 from the cursor toward the end of the edit buffer:
1600 a. If a character from the current line is displayed in the cur‐
1602 rent column, set to the last column that displays any portion
1603 of that character.
1604 b. Otherwise, set to the last column in which any portion of any
1606 character in the line is displayed.
1607 3. Otherwise, if a character is displayed in the column that began the
1609 text region, set to the last column that displays any portion of
1610 that character.
1611 4. Otherwise, set to the last column in which any portion of any char‐
1613 acter in the line is displayed.
1614 Delete to End-of-Line
1616 Synopsis:
1617 [buffer] D
1618 Delete the text from the current position to the end of the current
1620 line; equivalent to the vi command:
1621 [buffer] d$
1623 Move to End-of-Word
1625 Synopsis:
1626 [count] e
1627 With the exception that words are used instead of bigwords as the
1629 delimiter, this command shall be equivalent to the E command.
1630 Move to End-of-Bigword
1632 Synopsis:
1633 [count] E
1634 If the edit buffer is empty it shall be an error. If less than count
1636 bigwords end between the cursor and the end of the edit buffer, count
1637 shall be adjusted to the number of bigword endings between the cursor
1638 and the end of the edit buffer.
1639 If used as a motion command:
1641 1. The text region shall be from the last character of the countth
1643 next bigword up to and including the cursor character.
1644 2. Any text copied to a buffer shall be in character mode.
1646 If not used as a motion command:
1648 Current line: Set to the line containing the current column.
1650 Current column: Set to the last column upon which any part of the last
1652 character of the countth next bigword is displayed.
1653 Find Character in Current Line (Forward)
1655 Synopsis:
1656 [count] f character
1657 It shall be an error if count occurrences of the character do not occur
1659 after the cursor in the line.
1660 If used as a motion command:
1662 1. The text range shall be from the cursor character up to and includ‐
1664 ing the countth occurrence of the specified character after the
1665 cursor.
1666 2. Any text copied to a buffer shall be in character mode.
1668 If not used as a motion command:
1670 Current line: Unchanged.
1672 Current column: Set to the last column in which any portion of the
1674 countth occurrence of the specified character after the cursor appears
1675 in the line.
1676 Find Character in Current Line (Reverse)
1678 Synopsis:
1679 [count] F character
1680 It shall be an error if count occurrences of the character do not occur
1682 before the cursor in the line.
1683 If used as a motion command:
1685 1. The text region shall be from the countth occurrence of the speci‐
1687 fied character before the cursor, up to, but not including the cur‐
1688 sor character.
1689 2. Any text copied to a buffer shall be in character mode.
1691 If not used as a motion command:
1693 Current line: Unchanged.
1695 Current column: Set to the last column in which any portion of the
1697 countth occurrence of the specified character before the cursor appears
1698 in the line.
1699 Move to Line
1701 Synopsis:
1702 [count] G
1703 If count is not specified, it shall default to the last line of the
1705 edit buffer. If count is greater than the last line of the edit buf‐
1706 fer, it shall be an error.
1707 If used as a motion command:
1709 1. The text region shall be from the cursor line up to and including
1711 the specified line.
1712 2. Any text copied to a buffer shall be in line mode.
1714 If not used as a motion command:
1716 Current line: Set to count if count is specified; otherwise, the last
1718 line.
1719 Current column: Set to non-<blank>.
1721 Move to Top of Screen
1723 Synopsis:
1724 [count] H
1725 If the beginning of the line count greater than the first line of which
1727 any portion appears on the display does not exist, it shall be an
1728 error.
1729 If used as a motion command:
1731 1. If in open mode, the text region shall be the current line.
1733 2. Otherwise, the text region shall be from the starting line up to
1735 and including (the first line of the display + count −1).
1736 3. Any text copied to a buffer shall be in line mode.
1738 If not used as a motion command:
1740 If in open mode, this command shall set the current column to
1742 non-<blank> and do nothing else.
1743 Otherwise, it shall set the current line and current column as follows.
1745 Current line: Set to (the first line of the display + count −1).
1747 Current column: Set to non-<blank>.
1749 Insert Before Cursor
1751 Synopsis:
1752 [count] i
1753 Enter text input mode before the current cursor position. No characters
1755 already in the edit buffer shall be affected by this command. A count
1756 shall cause the input text to be appended count −1 more times to the
1757 end of the input.
1758 Current line/column: As specified for the text input commands (see
1760 Input Mode Commands in vi).
1761 Insert at Beginning of Line
1763 Synopsis:
1764 [count] I
1765 This command shall be equivalent to the vi command ^[count]i.
1767 Join
1769 Synopsis:
1770 [count] J
1771 If the current line is the last line in the edit buffer, it shall be an
1773 error.
1774 This command shall be equivalent to the ex join command with no
1776 addresses, and an ex command count value of 1 if count was not speci‐
1777 fied or if a count of 1 was specified, and an ex command count value of
1778 count −1 for any other value of count, except that the current line and
1779 column shall be set as follows.
1780 Current line: Unchanged.
1782 Current column: The last column in which any portion of the character
1784 following the last character in the initial line is displayed, or the
1785 last non-<newline> in the line if no characters were appended.
1786 Move to Bottom of Screen
1788 Synopsis:
1789 [count] L
1790 If the beginning of the line count less than the last line of which any
1792 portion appears on the display does not exist, it shall be an error.
1793 If used as a motion command:
1795 1. If in open mode, the text region shall be the current line.
1797 2. Otherwise, the text region shall include all lines from the start‐
1799 ing cursor line to (the last line of the display −(count −1)).
1800 3. Any text copied to a buffer shall be in line mode.
1802 If not used as a motion command:
1804 1. If in open mode, this command shall set the current column to
1806 non-<blank> and do nothing else.
1807 2. Otherwise, it shall set the current line and current column as fol‐
1809 lows.
1810 Current line: Set to (the last line of the display −(count −1)).
1812 Current column: Set to non-<blank>.
1814 Mark Position
1816 Synopsis:
1817 m letter
1818 This command shall be equivalent to the ex mark command with the speci‐
1820 fied character as an argument.
1821 Move to Middle of Screen
1823 Synopsis:
1824 M
1825 The middle line of the display shall be calculated as follows:
1827 (the top line of the display) + (((number of lines displayed) +1) /2) −1
1829 If used as a motion command:
1831 1. If in open mode, the text region shall be the current line.
1833 2. Otherwise, the text region shall include all lines from the start‐
1835 ing cursor line up to and including the middle line of the display.
1836 3. Any text copied to a buffer shall be in line mode.
1838 If not used as a motion command:
1840 If in open mode, this command shall set the current column to
1842 non-<blank> and do nothing else.
1843 Otherwise, it shall set the current line and current column as follows.
1845 Current line: Set to the middle line of the display.
1847 Current column: Set to non-<blank>.
1849 Repeat Regular Expression Find (Forward)
1851 Synopsis:
1852 n
1853 If the remembered search direction was forward, the n command shall be
1855 equivalent to the vi / command with no characters entered by the user.
1856 Otherwise, it shall be equivalent to the vi ? command with no charac‐
1857 ters entered by the user.
1858 If the n command is used as a motion command for the ! command, the
1860 editor shall not enter text input mode on the last line on the screen,
1861 and shall behave as if the user entered a single '!' character as the
1862 text input.
1863 Repeat Regular Expression Find (Reverse)
1865 Synopsis:
1866 N
1867 Scan for the next match of the last pattern given to / or ?, but in the
1869 reverse direction; this is the reverse of n.
1870 If the remembered search direction was forward, the N command shall be
1872 equivalent to the vi ? command with no characters entered by the user.
1873 Otherwise, it shall be equivalent to the vi / command with no charac‐
1874 ters entered by the user. If the N command is used as a motion command
1875 for the ! command, the editor shall not enter text input mode on the
1876 last line on the screen, and shall behave as if the user entered a sin‐
1877 gle ! character as the text input.
1878 Insert Empty Line Below
1880 Synopsis:
1881 o
1882 Enter text input mode in a new line appended after the current line. A
1884 count shall cause the input text to be appended count −1 more times to
1885 the end of the already added text, each time starting on a new,
1886 appended line.
1887 Current line/column: As specified for the text input commands (see
1889 Input Mode Commands in vi).
1890 Insert Empty Line Above
1892 Synopsis:
1893 O
1894 Enter text input mode in a new line inserted before the current line. A
1896 count shall cause the input text to be appended count −1 more times to
1897 the end of the already added text, each time starting on a new,
1898 appended line.
1899 Current line/column: As specified for the text input commands (see
1901 Input Mode Commands in vi).
1902 Put from Buffer Following
1904 Synopsis:
1905 [buffer] p
1906 If no buffer is specified, the unnamed buffer shall be used.
1908 If the buffer text is in line mode, the text shall be appended below
1910 the current line, and each line of the buffer shall become a new line
1911 in the edit buffer. A count shall cause the buffer text to be appended
1912 count −1 more times to the end of the already added text, each time
1913 starting on a new, appended line.
1914 If the buffer text is in character mode, the text shall be appended
1916 into the current line after the cursor, and each line of the buffer
1917 other than the first and last shall become a new line in the edit buf‐
1918 fer. A count shall cause the buffer text to be appended count −1 more
1919 times to the end of the already added text, each time starting after
1920 the last added character.
1921 Current line: If the buffer text is in line mode, set the line to line
1923 +1; otherwise, unchanged.
1924 Current column: If the buffer text is in line mode:
1926 1. If there is a non-<blank> in the first line of the buffer, set to
1928 the last column on which any portion of the first non-<blank> in
1929 the line is displayed.
1930 2. If there is no non-<blank> in the first line of the buffer, set to
1932 the last column on which any portion of the last non-<newline> in
1933 the first line of the buffer is displayed.
1934 If the buffer text is in character mode:
1936 1. If the text in the buffer is from more than a single line, then set
1938 to the last column on which any portion of the first character from
1939 the buffer is displayed.
1940 2. Otherwise, if the buffer is the unnamed buffer, set to the last
1942 column on which any portion of the last character from the buffer
1943 is displayed.
1944 3. Otherwise, set to the first column on which any portion of the
1946 first character from the buffer is displayed.
1947 Put from Buffer Before
1949 Synopsis:
1950 [buffer] P
1951 If no buffer is specified, the unnamed buffer shall be used.
1953 If the buffer text is in line mode, the text shall be inserted above
1955 the current line, and each line of the buffer shall become a new line
1956 in the edit buffer. A count shall cause the buffer text to be appended
1957 count −1 more times to the end of the already added text, each time
1958 starting on a new, appended line.
1959 If the buffer text is in character mode, the text shall be inserted
1961 into the current line before the cursor, and each line of the buffer
1962 other than the first and last shall become a new line in the edit buf‐
1963 fer. A count shall cause the buffer text to be appended count −1 more
1964 times to the end of the already added text, each time starting after
1965 the last added character.
1966 Current line: Unchanged.
1968 Current column: If the buffer text is in line mode:
1970 1. If there is a non-<blank> in the first line of the buffer, set to
1972 the last column on which any portion of that character is dis‐
1973 played.
1974 2. If there is no non-<blank> in the first line of the buffer, set to
1976 the last column on which any portion of the last non-<newline> in
1977 the first line of the buffer is displayed.
1978 If the buffer text is in character mode:
1980 1. If the text in the buffer is from more than a single line, then set
1982 to the last column on which any portion of the first character from
1983 the buffer is displayed.
1984 2. Otherwise, if the buffer is the unnamed buffer, set to the last
1986 column on which any portion of the last character from the buffer
1987 is displayed.
1988 3. Otherwise, set to the first column on which any portion of the
1990 first character from the buffer is displayed.
1991 Enter ex Mode
1993 Synopsis:
1994 Q
1995 Leave visual or open mode and enter ex command mode.
1997 Current line: Unchanged.
1999 Current column: Unchanged.
2001 Replace Character
2003 Synopsis:
2004 [count] r character
2005 Replace the count characters at and after the cursor with the specified
2007 character. If there are less than count non-<newline> characters at and
2008 after the cursor on the line, it shall be an error.
2009 If character is <control>‐V, any next character other than the <new‐
2011 line> shall be stripped of any special meaning and used as a literal
2012 character.
2013 If character is <ESC>, no replacement shall be made and the current
2015 line and current column shall be unchanged.
2016 If character is <carriage-return> or <newline>, count new lines shall
2018 be appended to the current line. All but the last of these lines shall
2019 be empty. count characters at and after the cursor shall be discarded,
2020 and any remaining characters after the cursor in the current line shall
2021 be moved to the last of the new lines. If the autoindent edit option is
2022 set, they shall be preceded by the same number of autoindent characters
2023 found on the line from which the command was executed.
2024 Current line: Unchanged unless the replacement character is a <car‐
2026 riage-return> or <newline>, in which case it shall be set to line +
2027 count.
2028 Current column: Set to the last column position on which a portion of
2030 the last replaced character is displayed, or if the replacement charac‐
2031 ter caused new lines to be created, set to non-<blank>.
2032 Replace Characters
2034 Synopsis:
2035 R
2036 Enter text input mode at the current cursor position possibly replacing
2038 text on the current line. A count shall cause the input text to be
2039 appended count −1 more times to the end of the input.
2040 Current line/column: As specified for the text input commands (see
2042 Input Mode Commands in vi).
2043 Substitute Character
2045 Synopsis:
2046 [buffer][count] s
2047 This command shall be equivalent to the vi command:
2049 [buffer][count] c<space>
2051 Substitute Lines
2053 Synopsis:
2054 [buffer][count] S
2055 This command shall be equivalent to the vi command:
2057 [buffer][count] c_
2059 Move Cursor to Before Character (Forward)
2061 Synopsis:
2062 [count] t character
2063 It shall be an error if count occurrences of the character do not occur
2065 after the cursor in the line.
2066 If used as a motion command:
2068 1. The text region shall be from the cursor up to but not including
2070 the countth occurrence of the specified character after the cursor.
2071 2. Any text copied to a buffer shall be in character mode.
2073 If not used as a motion command:
2075 Current line: Unchanged.
2077 Current column: Set to the last column in which any portion of the
2079 character before the countth occurrence of the specified character
2080 after the cursor appears in the line.
2081 Move Cursor to After Character (Reverse)
2083 Synopsis:
2084 [count] T character
2085 It shall be an error if count occurrences of the character do not occur
2087 before the cursor in the line.
2088 If used as a motion command:
2090 1. If the character before the cursor is the specified character, it
2092 shall be an error.
2093 2. The text region shall be from the character before the cursor up to
2095 but not including the countth occurrence of the specified character
2096 before the cursor.
2097 3. Any text copied to a buffer shall be in character mode.
2099 If not used as a motion command:
2101 Current line: Unchanged.
2103 Current column: Set to the last column in which any portion of the
2105 character after the countth occurrence of the specified character
2106 before the cursor appears in the line.
2107 Undo
2109 Synopsis:
2110 u
2111 This command shall be equivalent to the ex undo command except that the
2113 current line and current column shall be set as follows:
2114 Current line: Set to the first line added or changed if any; otherwise,
2116 move to the line preceding any deleted text if one exists; otherwise,
2117 move to line 1.
2118 Current column: If undoing an ex command, set to the first non-<blank>.
2120 Otherwise, if undoing a text input command:
2122 1. If the command was a C, c, O, o, R, S, or s command, the current
2124 column shall be set to the value it held when the text input com‐
2125 mand was entered.
2126 2. Otherwise, set to the last column in which any portion of the first
2128 character after the deleted text is displayed, or, if no non-<new‐
2129 line> characters follow the text deleted from this line, set to the
2130 last column in which any portion of the last non-<newline> in the
2131 line is displayed, or 1 if the line is empty.
2132 Otherwise, if a single line was modified (that is, not added or
2134 deleted) by the u command:
2135 1. If text was added or changed, set to the last column in which any
2137 portion of the first character added or changed is displayed.
2138 2. If text was deleted, set to the last column in which any portion of
2140 the first character after the deleted text is displayed, or, if no
2141 non-<newline> characters follow the deleted text, set to the last
2142 column in which any portion of the last non-<newline> in the line
2143 is displayed, or 1 if the line is empty.
2144 Otherwise, set to non-<blank>.
2146 Undo Current Line
2148 Synopsis:
2149 U
2150 Restore the current line to its state immediately before the most
2152 recent time that it became the current line.
2153 Current line: Unchanged.
2155 Current column: Set to the first column in the line in which any por‐
2157 tion of the first character in the line is displayed.
2158 Move to Beginning of Word
2160 Synopsis:
2161 [count] w
2162 With the exception that words are used as the delimiter instead of big‐
2164 words, this command shall be equivalent to the W command.
2165 Move to Beginning of Bigword
2167 Synopsis:
2168 [count] W
2169 If the edit buffer is empty, it shall be an error. If there are less
2171 than count bigwords between the cursor and the end of the edit buffer,
2172 count shall be adjusted to move the cursor to the last bigword in the
2173 edit buffer.
2174 If used as a motion command:
2176 1. If the associated command is c, count is 1, and the cursor is on a
2178 <blank>, the region of text shall be the current character and no
2179 further action shall be taken.
2180 2. If there are less than count bigwords between the cursor and the
2182 end of the edit buffer, then the command shall succeed, and the
2183 region of text shall include the last character of the edit buffer.
2184 3. If there are <blank> characters or an end-of-line that precede the
2186 countth bigword, and the associated command is c, the region of
2187 text shall be up to and including the last character before the
2188 preceding <blank> characters or end-of-line.
2189 4. If there are <blank> characters or an end-of-line that precede the
2191 bigword, and the associated command is d or y, the region of text
2192 shall be up to and including the last <blank> before the start of
2193 the bigword or end-of-line.
2194 5. Any text copied to a buffer shall be in character mode.
2196 If not used as a motion command:
2198 1. If the cursor is on the last character of the edit buffer, it shall
2200 be an error.
2201 Current line: Set to the line containing the current column.
2203 Current column: Set to the last column in which any part of the first
2205 character of the countth next bigword is displayed.
2206 Delete Character at Cursor
2208 Synopsis:
2209 [buffer][count] x
2210 Delete the count characters at and after the current character into
2212 buffer, if specified, and into the unnamed buffer.
2213 If the line is empty, it shall be an error. If there are less than
2215 count non-<newline> characters at and after the cursor on the current
2216 line, count shall be adjusted to the number of non-<newline> characters
2217 at and after the cursor.
2218 Current line: Unchanged.
2220 Current column: If the line is empty, set to column position 1. Other‐
2222 wise, if there were count or less non-<newline> characters at and after
2223 the cursor on the current line, set to the last column that displays
2224 any part of the last non-<newline> of the line. Otherwise, unchanged.
2225 Delete Character Before Cursor
2227 Synopsis:
2228 [buffer][count] X
2229 Delete the count characters before the current character into buffer,
2231 if specified, and into the unnamed buffer.
2232 If there are no characters before the current character on the current
2234 line, it shall be an error. If there are less than count previous char‐
2235 acters on the current line, count shall be adjusted to the number of
2236 previous characters on the line.
2237 Current line: Unchanged.
2239 Current column: Set to (current column − the width of the deleted char‐
2241 acters).
2242 Yank
2244 Synopsis:
2245 [buffer][count] y motion
2246 Copy (yank) the region of text into buffer, if specified, and into the
2248 unnamed buffer.
2249 If the motion command is the y command repeated:
2251 1. The buffer shall be in line mode.
2253 2. If there are less than count −1 lines after the current line in the
2255 edit buffer, it shall be an error.
2256 3. The text region shall be from the current line up to and including
2258 the next count −1 lines.
2259 Otherwise, the buffer text mode and text region shall be as specified
2261 by the motion command.
2262 Current line: If the motion was from the current cursor position toward
2264 the end of the edit buffer, unchanged. Otherwise, set to the first line
2265 in the edit buffer that is part of the text region specified by the
2266 motion command.
2267 Current column:
2269 1. If the motion was from the current cursor position toward the end
2271 of the edit buffer, unchanged.
2272 2. Otherwise, if the current line is empty, set to column position 1.
2274 3. Otherwise, set to the last column that displays any part of the
2276 first character in the file that is part of the text region speci‐
2277 fied by the motion command.
2278 Yank Current Line
2280 Synopsis:
2281 [buffer][count] Y
2282 This command shall be equivalent to the vi command:
2284 [buffer][count] y_
2286 Redraw Window
2288 If in open mode, the z command shall have the Synopsis:
2289 Synopsis:
2291 [count] z
2292 If count is not specified, it shall default to the window edit option
2294 −1. The z command shall be equivalent to the ex z command, with a type
2295 character of = and a count of count −2, except that the current line
2296 and current column shall be set as follows, and the window edit option
2297 shall not be affected. If the calculation for the count argument would
2298 result in a negative number, the count argument to the ex z command
2299 shall be zero. A blank line shall be written after the last line is
2300 written.
2301 Current line: Unchanged.
2303 Current column: Unchanged.
2305 If not in open mode, the z command shall have the following Synopsis:
2307 Synopsis:
2309 [line] z [count] character
2310 If line is not specified, it shall default to the current line. If line
2312 is specified, but is greater than the number of lines in the edit buf‐
2313 fer, it shall default to the number of lines in the edit buffer.
2314 If count is specified, the value of the window edit option shall be set
2316 to count (as described in the ex window command), and the screen shall
2317 be redrawn.
2318 line shall be placed as specified by the following characters:
2320 <newline>, <carriage-return>
2322 Place the beginning of the line on the first line of the display.
2323 . Place the beginning of the line in the center of the display. The
2325 middle line of the display shall be calculated as described for
2326 the M command.
2327 − Place an unspecified portion of the line on the last line of the
2329 display.
2330 + If line was specified, equivalent to the <newline> case. If line
2332 was not specified, display a screen where the first line of the
2333 display shall be (current last line) +1. If there are no lines
2334 after the last line in the display, it shall be an error.
2335 ^ If line was specified, display a screen where the last line of
2337 the display shall contain an unspecified portion of the first
2338 line of a display that had an unspecified portion of the speci‐
2339 fied line on the last line of the display. If this calculation
2340 results in a line before the beginning of the edit buffer, dis‐
2341 play the first screen of the edit buffer.
2342 Otherwise, display a screen where the last line of the display
2344 shall contain an unspecified portion of (current first line −1).
2345 If this calculation results in a line before the beginning of the
2346 edit buffer, it shall be an error.
2347 Current line: If line and the '^' character were specified:
2349 1. If the first screen was displayed as a result of the command
2351 attempting to display lines before the beginning of the edit buf‐
2352 fer: if the first screen was already displayed, unchanged; other‐
2353 wise, set to (current first line −1).
2354 2. Otherwise, set to the last line of the display.
2356 If line and the '+' character were specified, set to the first line of
2358 the display.
2359 Otherwise, if line was specified, set to line.
2361 Otherwise, unchanged.
2363 Current column: Set to non-<blank>.
2365 Exit
2367 Synopsis:
2368 ZZ
2369 This command shall be equivalent to the ex xit command with no
2371 addresses, trailing !, or filename (see the ex xit command).
2372 Input Mode Commands in vi
2374 In text input mode, the current line shall consist of zero or more of
2375 the following categories, plus the terminating <newline>:
2376 1. Characters preceding the text input entry point
2378 Characters in this category shall not be modified during text input
2380 mode.
2381 2. autoindent characters
2383 autoindent characters shall be automatically inserted into each
2385 line that is created in text input mode, either as a result of
2386 entering a <newline> or <carriage-return> while in text input mode,
2387 or as an effect of the command itself; for example, O or o (see the
2388 ex autoindent command), as if entered by the user.
2389 It shall be possible to erase autoindent characters with the <con‐
2391 trol>‐D command; it is unspecified whether they can be erased by
2392 <control>‐H, <control>‐U, and <control>‐W characters. Erasing any
2393 autoindent character turns the glyph into erase-columns and deletes
2394 the character from the edit buffer, but does not change its repre‐
2395 sentation on the screen.
2396 3. Text input characters
2398 Text input characters are the characters entered by the user. Eras‐
2400 ing any text input character turns the glyph into erase-columns and
2401 deletes the character from the edit buffer, but does not change its
2402 representation on the screen.
2403 Each text input character entered by the user (that does not have a
2405 special meaning) shall be treated as follows:
2406 a. The text input character shall be appended to the last charac‐
2408 ter in the edit buffer from the first, second, or third cate‐
2409 gories.
2410 b. If there are no erase-columns on the screen, the text input
2412 command was the R command, and characters in the fifth category
2413 from the original line follow the cursor, the next such charac‐
2414 ter shall be deleted from the edit buffer. If the slowopen edit
2415 option is not set, the corresponding glyph on the screen shall
2416 become erase-columns.
2417 c. If there are erase-columns on the screen, as many columns as
2419 they occupy, or as are necessary, shall be overwritten to dis‐
2420 play the text input character. (If only part of a multi-column
2421 glyph is overwritten, the remainder shall be left on the
2422 screen, and continue to be treated as erase-columns; it is
2423 unspecified whether the remainder of the glyph is modified in
2424 any way.)
2425 d. If additional display line columns are needed to display the
2427 text input character:
2428 i. If the slowopen edit option is set, the text input charac‐
2430 ters shall be displayed on subsequent display line col‐
2431 umns, overwriting any characters displayed in those col‐
2432 umns.
2433 ii. Otherwise, any characters currently displayed on or after
2435 the column on the display line where the text input char‐
2436 acter is to be displayed shall be pushed ahead the number
2437 of display line columns necessary to display the rest of
2438 the text input character.
2439 4. Erase-columns
2441 Erase-columns are not logically part of the edit buffer, appearing
2443 only on the screen, and may be overwritten on the screen by subse‐
2444 quent text input characters. When text input mode ends, all erase-
2445 columns shall no longer appear on the screen.
2446 Erase-columns are initially the region of text specified by the c
2448 command (see Change); however, erasing autoindent or text input
2449 characters causes the glyphs of the erased characters to be treated
2450 as erase-columns.
2451 5. Characters following the text region for the c command, or the text
2453 input entry point for all other commands
2454 Characters in this category shall not be modified during text input
2456 mode, except as specified in category 3.b. for the R text input
2457 command, or as <blank> characters deleted when a <newline> or <car‐
2458 riage-return> is entered.
2459 It is unspecified whether it is an error to attempt to erase past the
2461 beginning of a line that was created by the entry of a <newline> or
2462 <carriage-return> during text input mode. If it is not an error, the
2463 editor shall behave as if the erasing character was entered immediately
2464 after the last text input character entered on the previous line, and
2465 all of the non-<newline> characters on the current line shall be
2466 treated as erase-columns.
2467 When text input mode is entered, or after a text input mode character
2469 is entered (except as specified for the special characters below), the
2470 cursor shall be positioned as follows:
2471 1. On the first column that displays any part of the first erase-col‐
2473 umn, if one exists
2474 2. Otherwise, if the slowopen edit option is set, on the first display
2476 line column after the last character in the first, second, or third
2477 categories, if one exists
2478 3. Otherwise, the first column that displays any part of the first
2480 character in the fifth category, if one exists
2481 4. Otherwise, the display line column after the last character in the
2483 first, second, or third categories, if one exists
2484 5. Otherwise, on column position 1
2486 The characters that are updated on the screen during text input mode
2488 are unspecified, other than that the last text input character shall
2489 always be updated, and, if the slowopen edit option is not set, the
2490 current cursor character shall always be updated.
2491 The following specifications are for command characters entered during
2493 text input mode.
2494 NUL
2496 Synopsis:
2497 NUL
2498 If the first character of the text input is a NUL, the most recently
2500 input text shall be input as if entered by the user, and then text
2501 input mode shall be exited. The text shall be input literally; that is,
2502 characters are neither macro or abbreviation expanded, nor are any
2503 characters interpreted in any special manner. It is unspecified whether
2504 implementations shall support more than 256 bytes of remembered input
2505 text.
2506 <control>-D
2508 Synopsis:
2509 <control>-D
2510 The <control>‐D character shall have no special meaning when in text
2512 input mode for a line-oriented command (see Command Descriptions in
2513 vi).
2514 This command need not be supported on block-mode terminals.
2516 If the cursor does not follow an autoindent character, or an autoindent
2518 character and a '0' or '^' character:
2519 1. If the cursor is in column position 1, the <control>‐D character
2521 shall be discarded and no further action taken.
2522 2. Otherwise, the <control>‐D character shall have no special meaning.
2524 If the last input character was a '0', the cursor shall be moved to
2526 column position 1.
2527 Otherwise, if the last input character was a '^', the cursor shall be
2529 moved to column position 1. In addition, the autoindent level for the
2530 next input line shall be derived from the same line from which the
2531 autoindent level for the current input line was derived.
2532 Otherwise, the cursor shall be moved back to the column after the pre‐
2534 vious shiftwidth (see the ex shiftwidth command) boundary.
2535 All of the glyphs on columns between the starting cursor position and
2537 (inclusively) the ending cursor position shall become erase-columns as
2538 described in Input Mode Commands in vi.
2539 Current line: Unchanged.
2541 Current column: Set to 1 if the <control>‐D was preceded by a '^' or
2543 '0'; otherwise, set to (column −1) −((column −2) % shiftwidth).
2544 <control>-H
2546 Synopsis:
2547 <control>-H
2548 If in text input mode for a line-oriented command, and there are no
2550 characters to erase, text input mode shall be terminated, no further
2551 action shall be done for this command, and the current line and column
2552 shall be unchanged.
2553 If there are characters other than autoindent characters that have been
2555 input on the current line before the cursor, the cursor shall move back
2556 one character.
2557 Otherwise, if there are autoindent characters on the current line
2559 before the cursor, it is implementation-defined whether the <control>‐H
2560 command is an error or if the cursor moves back one autoindent charac‐
2561 ter.
2562 Otherwise, if the cursor is in column position 1 and there are previous
2564 lines that have been input, it is implementation-defined whether the
2565 <control>‐H command is an error or if it is equivalent to entering
2566 <control>‐H after the last input character on the previous input line.
2567 Otherwise, it shall be an error.
2569 All of the glyphs on columns between the starting cursor position and
2571 (inclusively) the ending cursor position shall become erase-columns as
2572 described in Input Mode Commands in vi.
2573 The current erase character (see stty) shall cause an equivalent action
2575 to the <control>‐H command, unless the previously inserted character
2576 was a <backslash>, in which case it shall be as if the literal current
2577 erase character had been inserted instead of the <backslash>.
2578 Current line: Unchanged, unless previously input lines are erased, in
2580 which case it shall be set to line −1.
2581 Current column: Set to the first column that displays any portion of
2583 the character backed up over.
2584 <newline>
2586 Synopsis:
2587 <newline>
2588 <carriage-return>
2589 <control>-J
2590 <control>-M
2591 If input was part of a line-oriented command, text input mode shall be
2593 terminated and the command shall continue execution with the input pro‐
2594 vided.
2595 Otherwise, terminate the current line. If there are no characters other
2597 than autoindent characters on the line, all characters on the line
2598 shall be discarded. Otherwise, it is unspecified whether the autoin‐
2599 dent characters in the line are modified by entering these characters.
2600 Continue text input mode on a new line appended after the current line.
2602 If the slowopen edit option is set, the lines on the screen below the
2603 current line shall not be pushed down, but the first of them shall be
2604 cleared and shall appear to be overwritten. Otherwise, the lines of the
2605 screen below the current line shall be pushed down.
2606 If the autoindent edit option is set, an appropriate number of autoin‐
2608 dent characters shall be added as a prefix to the line as described by
2609 the ex autoindent edit option.
2610 All columns after the cursor that are erase-columns (as described in
2612 Input Mode Commands in vi) shall be discarded.
2613 If the autoindent edit option is set, all <blank> characters immedi‐
2615 ately following the cursor shall be discarded.
2616 All remaining characters after the cursor shall be transferred to the
2618 new line, positioned after any autoindent characters.
2619 Current line: Set to current line +1.
2621 Current column: Set to the first column that displays any portion of
2623 the first character after the autoindent characters on the new line, if
2624 any, or the first column position after the last autoindent character,
2625 if any, or column position 1.
2626 <control>-T
2628 Synopsis:
2629 <control>-T
2630 The <control>‐T character shall have no special meaning when in text
2632 input mode for a line-oriented command (see Command Descriptions in
2633 vi).
2634 This command need not be supported on block-mode terminals.
2636 Behave as if the user entered the minimum number of <blank> characters
2638 necessary to move the cursor forward to the column position after the
2639 next shiftwidth (see the ex shiftwidth command) boundary.
2640 Current line: Unchanged.
2642 Current column: Set to column + shiftwidth − ((column −1) %
2644 shiftwidth).
2645 <control>-U
2647 Synopsis:
2648 <control>-U
2649 If there are characters other than autoindent characters that have been
2651 input on the current line before the cursor, the cursor shall move to
2652 the first character input after the autoindent characters.
2653 Otherwise, if there are autoindent characters on the current line
2655 before the cursor, it is implementation-defined whether the <control>‐U
2656 command is an error or if the cursor moves to the first column position
2657 on the line.
2658 Otherwise, if the cursor is in column position 1 and there are previous
2660 lines that have been input, it is implementation-defined whether the
2661 <control>‐U command is an error or if it is equivalent to entering
2662 <control>‐U after the last input character on the previous input line.
2663 Otherwise, it shall be an error.
2665 All of the glyphs on columns between the starting cursor position and
2667 (inclusively) the ending cursor position shall become erase-columns as
2668 described in Input Mode Commands in vi.
2669 The current kill character (see stty) shall cause an equivalent action
2671 to the <control>‐U command, unless the previously inserted character
2672 was a <backslash>, in which case it shall be as if the literal current
2673 kill character had been inserted instead of the <backslash>.
2674 Current line: Unchanged, unless previously input lines are erased, in
2676 which case it shall be set to line −1.
2677 Current column: Set to the first column that displays any portion of
2679 the last character backed up over.
2680 <control>-V
2682 Synopsis:
2683 <control>-V
2684 <control>-Q
2685 Allow the entry of any subsequent character, other than <control>‐J or
2687 the <newline>, as a literal character, removing any special meaning
2688 that it may have to the editor in text input mode. If a <control>‐V or
2689 <control>‐Q is entered before a <control>‐J or <newline>, the <con‐
2690 trol>‐V or <control>‐Q character shall be discarded, and the <con‐
2691 trol>‐J or <newline> shall behave as described in the <newline> command
2692 character during input mode.
2693 For purposes of the display only, the editor shall behave as if a '^'
2695 character was entered, and the cursor shall be positioned as if over‐
2696 writing the '^' character. When a subsequent character is entered, the
2697 editor shall behave as if that character was entered instead of the
2698 original <control>‐V or <control>‐Q character.
2699 Current line: Unchanged.
2701 Current column: Unchanged.
2703 <control>-W
2705 Synopsis:
2706 <control>-W
2707 If there are characters other than autoindent characters that have been
2709 input on the current line before the cursor, the cursor shall move back
2710 over the last word preceding the cursor (including any <blank> charac‐
2711 ters between the end of the last word and the current cursor); the cur‐
2712 sor shall not move to before the first character after the end of any
2713 autoindent characters.
2714 Otherwise, if there are autoindent characters on the current line
2716 before the cursor, it is implementation-defined whether the <control>‐W
2717 command is an error or if the cursor moves to the first column position
2718 on the line.
2719 Otherwise, if the cursor is in column position 1 and there are previous
2721 lines that have been input, it is implementation-defined whether the
2722 <control>‐W command is an error or if it is equivalent to entering
2723 <control>‐W after the last input character on the previous input line.
2724 Otherwise, it shall be an error.
2726 All of the glyphs on columns between the starting cursor position and
2728 (inclusively) the ending cursor position shall become erase-columns as
2729 described in Input Mode Commands in vi.
2730 Current line: Unchanged, unless previously input lines are erased, in
2732 which case it shall be set to line −1.
2733 Current column: Set to the first column that displays any portion of
2735 the last character backed up over.
2736 <ESC>
2738 Synopsis:
2739 <ESC>
2740 If input was part of a line-oriented command:
2742 1. If interrupt was entered, text input mode shall be terminated and
2744 the editor shall return to command mode. The terminal shall be
2745 alerted.
2746 2. If <ESC> was entered, text input mode shall be terminated and the
2748 command shall continue execution with the input provided.
2749 Otherwise, terminate text input mode and return to command mode.
2751 Any autoindent characters entered on newly created lines that have no
2753 other non-<newline> characters shall be deleted.
2754 Any leading autoindent and <blank> characters on newly created lines
2756 shall be rewritten to be the minimum number of <blank> characters pos‐
2757 sible.
2758 The screen shall be redisplayed as necessary to match the contents of
2760 the edit buffer.
2761 Current line: Unchanged.
2763 Current column:
2765 1. If there are text input characters on the current line, the column
2767 shall be set to the last column where any portion of the last text
2768 input character is displayed.
2769 2. Otherwise, if a character is displayed in the current column,
2771 unchanged.
2772 3. Otherwise, set to column position 1.
2774
2776 The following exit values shall be returned:
2777 0 Successful completion.
2779 >0 An error occurred.
2781
2783 When any error is encountered and the standard input is not a terminal
2784 device file, vi shall not write the file or return to command or text
2785 input mode, and shall terminate with a non-zero exit status.
2786 Otherwise, when an unrecoverable error is encountered it shall be
2788 equivalent to a SIGHUP asynchronous event.
2789 Otherwise, when an error is encountered, the editor shall behave as
2791 specified in Command Descriptions in vi.
2792 The following sections are informative.
2794
2796 None.
2797
2799 None.
2800
2802 See the RATIONALE for ex for more information on vi. Major portions of
2803 the vi utility specification point to ex to avoid inadvertent diver‐
2804 gence. While ex and vi have historically been implemented as a single
2805 utility, this is not required by POSIX.1‐2008.
2806 It is recognized that portions of vi would be difficult, if not impos‐
2808 sible, to implement satisfactorily on a block-mode terminal, or a ter‐
2809 minal without any form of cursor addressing, thus it is not a mandatory
2810 requirement that such features should work on all terminals. It is the
2811 intention, however, that a vi implementation should provide the full
2812 set of capabilities on all terminals capable of supporting them.
2813 Historically, vi exited immediately if the standard input was not a
2815 terminal. POSIX.1‐2008 permits, but does not require, this behavior. An
2816 end-of-file condition is not equivalent to an end-of-file character. A
2817 common end-of-file character, <control>‐D, is historically a vi com‐
2818 mand.
2819 The text in the STDOUT section reflects the usage of the verb display
2821 in this section; some implementations of vi use standard output to
2822 write to the terminal, but POSIX.1‐2008 does not require that to be the
2823 case.
2824 Historically, implementations reverted to open mode if the terminal was
2826 incapable of supporting full visual mode. POSIX.1‐2008 requires this
2827 behavior. Historically, the open mode of vi behaved roughly equiva‐
2828 lently to the visual mode, with the exception that only a single line
2829 from the edit buffer (one ``buffer line'') was kept current at any
2830 time. This line was normally displayed on the next-to-last line of a
2831 terminal with cursor addressing (and the last line performed its normal
2832 visual functions for line-oriented commands and messages). In addition,
2833 some few commands behaved differently in open mode than in visual mode.
2834 POSIX.1‐2008 requires conformance to historical practice.
2835 Historically, ex and vi implementations have expected text to proceed
2837 in the usual European/Latin order of left to right, top to bottom.
2838 There is no requirement in POSIX.1‐2008 that this be the case. The
2839 specification was deliberately written using words like ``before'',
2840 ``after'', ``first'', and ``last'' in order to permit implementations
2841 to support the natural text order of the language.
2842 Historically, lines past the end of the edit buffer were marked with
2844 single <tilde> ('~') characters; that is, if the one-based display was
2845 20 lines in length, and the last line of the file was on line one, then
2846 lines 2-20 would contain only a single '~' character.
2847 Historically, the vi editor attempted to display only complete lines at
2849 the bottom of the screen (it did display partial lines at the top of
2850 the screen). If a line was too long to fit in its entirety at the bot‐
2851 tom of the screen, the screen lines where the line would have been dis‐
2852 played were displayed as single '@' characters, instead of displaying
2853 part of the line. POSIX.1‐2008 permits, but does not require, this
2854 behavior. Implementations are encouraged to attempt always to display a
2855 complete line at the bottom of the screen when doing scrolling or
2856 screen positioning by buffer lines.
2857 Historically, lines marked with '@' were also used to minimize output
2859 to dumb terminals over slow lines; that is, changes local to the cursor
2860 were updated, but changes to lines on the screen that were not close to
2861 the cursor were simply marked with an '@' sign instead of being updated
2862 to match the current text. POSIX.1‐2008 permits, but does not require
2863 this feature because it is used ever less frequently as terminals
2864 become smarter and connections are faster.
2865 Initialization in ex and vi
2867 Historically, vi always had a line in the edit buffer, even if the edit
2868 buffer was ``empty''. For example:
2869 1. The ex command = executed from visual mode wrote ``1'' when the
2871 buffer was empty.
2872 2. Writes from visual mode of an empty edit buffer wrote files of a
2874 single character (a <newline>), while writes from ex mode of an
2875 empty edit buffer wrote empty files.
2876 3. Put and read commands into an empty edit buffer left an empty line
2878 at the top of the edit buffer.
2879 For consistency, POSIX.1‐2008 does not permit any of these behaviors.
2881 Historically, vi did not always return the terminal to its original
2883 modes; for example, ICRNL was modified if it was not originally set.
2884 POSIX.1‐2008 does not permit this behavior.
2885 Command Descriptions in vi
2887 Motion commands are among the most complicated aspects of vi to
2888 describe. With some exceptions, the text region and buffer type effect
2889 of a motion command on a vi command are described on a case-by-case
2890 basis. The descriptions of text regions in POSIX.1‐2008 are not
2891 intended to imply direction; that is, an inclusive region from line n
2892 to line n+5 is identical to a region from line n+5 to line n. This is
2893 of more than academic interest—movements to marks can be in either
2894 direction, and, if the wrapscan option is set, so can movements to
2895 search points. Historically, lines are always stored into buffers in
2896 text order; that is, from the start of the edit buffer to the end.
2897 POSIX.1‐2008 requires conformance to historical practice.
2898 Historically, command counts were applied to any associated motion, and
2900 were multiplicative to any supplied motion count. For example, 2cw is
2901 the same as c2w, and 2c3w is the same as c6w. POSIX.1‐2008 requires
2902 this behavior. Historically, vi commands that used bigwords, words,
2903 paragraphs, and sentences as objects treated groups of empty lines, or
2904 lines that contained only <blank> characters, inconsistently. Some com‐
2905 mands treated them as a single entity, while others treated each line
2906 separately. For example, the w, W, and B commands treated groups of
2907 empty lines as individual words; that is, the command would move the
2908 cursor to each new empty line. The e and E commands treated groups of
2909 empty lines as a single word; that is, the first use would move past
2910 the group of lines. The b command would just beep at the user, or if
2911 done from the start of the line as a motion command, fail in unexpected
2912 ways. If the lines contained only (or ended with) <blank> characters,
2913 the w and W commands would just beep at the user, the E and e commands
2914 would treat the group as a single word, and the B and b commands would
2915 treat the lines as individual words. For consistency and simplicity of
2916 specification, POSIX.1‐2008 requires that all vi commands treat groups
2917 of empty or blank lines as a single entity, and that movement through
2918 lines ending with <blank> characters be consistent with other move‐
2919 ments.
2920 Historically, vi documentation indicated that any number of double-
2922 quotes were skipped after punctuation marks at sentence boundaries;
2923 however, implementations only skipped single-quotes. POSIX.1‐2008
2924 requires both to be skipped.
2925 Historically, the first and last characters in the edit buffer were
2927 word boundaries. This historical practice is required by POSIX.1‐2008.
2928 Historically, vi attempted to update the minimum number of columns on
2930 the screen possible, which could lead to misleading information being
2931 displayed. POSIX.1‐2008 makes no requirements other than that the cur‐
2932 rent character being entered is displayed correctly, leaving all other
2933 decisions in this area up to the implementation.
2934 Historically, lines were arbitrarily folded between columns of any
2936 characters that required multiple column positions on the screen, with
2937 the exception of tabs, which terminated at the right-hand margin.
2938 POSIX.1‐2008 permits the former and requires the latter. Implementa‐
2939 tions that do not arbitrarily break lines between columns of characters
2940 that occupy multiple column positions should not permit the cursor to
2941 rest on a column that does not contain any part of a character.
2942 The historical vi had a problem in that all movements were by buffer
2944 lines, not by display or screen lines. This is often the right thing to
2945 do; for example, single line movements, such as j or k, should work on
2946 buffer lines. Commands like dj, or j., where . is a change command,
2947 only make sense for buffer lines. It is not, however, the right thing
2948 to do for screen motion or scrolling commands like <control>‐D, <con‐
2949 trol>‐F, and H. If the window is fairly small, using buffer lines in
2950 these cases can result in completely random motion; for example, 1<con‐
2951 trol>‐D can result in a completely changed screen, without any overlap.
2952 This is clearly not what the user wanted. The problem is even worse in
2953 the case of the H, L, and M commands—as they position the cursor at the
2954 first non-<blank> of the line, they may all refer to the same location
2955 in large lines, and will result in no movement at all.
2956 In addition, if the line is larger than the screen, using buffer lines
2958 can make it impossible to display parts of the line—there are not any
2959 commands that do not display the beginning of the line in historical
2960 vi, and if both the beginning and end of the line cannot be on the
2961 screen at the same time, the user suffers. Finally, the page and half-
2962 page scrolling commands historically moved to the first non-<blank> in
2963 the new line. If the line is approximately the same size as the screen,
2964 this is inadequate because the cursor before and after a <control>‐D
2965 command will refer to the same location on the screen.
2966 Implementations of ex and vi exist that do not have these problems
2968 because the relevant commands (<control>‐B, <control>‐D, <control>‐F,
2969 <control>‐U, <control>‐Y, <control>‐E, H, L, and M) operate on display
2970 (screen) lines, not (edit) buffer lines.
2971 POSIX.1‐2008 does not permit this behavior by default because the stan‐
2973 dard developers believed that users would find it too confusing. How‐
2974 ever, historical practice has been relaxed. For example, ex and vi his‐
2975 torically attempted, albeit sometimes unsuccessfully, to never put part
2976 of a line on the last lines of a screen; for example, if a line would
2977 not fit in its entirety, no part of the line was displayed, and the
2978 screen lines corresponding to the line contained single '@' characters.
2979 This behavior is permitted, but not required by POSIX.1‐2008, so that
2980 it is possible for implementations to support long lines in small
2981 screens more reasonably without changing the commands to be oriented to
2982 the display (instead of oriented to the buffer). POSIX.1‐2008 also per‐
2983 mits implementations to refuse to edit any edit buffer containing a
2984 line that will not fit on the screen in its entirety.
2985 The display area (for example, the value of the window edit option) has
2987 historically been ``grown'', or expanded, to display new text when
2988 local movements are done in displays where the number of lines dis‐
2989 played is less than the maximum possible. Expansion has historically
2990 been the first choice, when the target line is less than the maximum
2991 possible expansion value away. Scrolling has historically been the next
2992 choice, done when the target line is less than half a display away, and
2993 otherwise, the screen was redrawn. There were exceptions, however, in
2994 that ex commands generally always caused the screen to be redrawn.
2995 POSIX.1‐2008 does not specify a standard behavior because there may be
2996 external issues, such as connection speed, the number of characters
2997 necessary to redraw as opposed to scroll, or terminal capabilities that
2998 implementations will have to accommodate.
2999 The current line in POSIX.1‐2008 maps one-to-one to a buffer line in
3001 the file. The current column does not. There are two different column
3002 values that are described by POSIX.1‐2008. The first is the current
3003 column value as set by many of the vi commands. This value is remem‐
3004 bered for the lifetime of the editor. The second column value is the
3005 actual position on the screen where the cursor rests. The two are not
3006 always the same. For example, when the cursor is backed by a multi-col‐
3007 umn character, the actual cursor position on the screen has histori‐
3008 cally been the last column of the character in command mode, and the
3009 first column of the character in input mode.
3010 Commands that set the current line, but that do not set the current
3012 cursor value (for example, j and k) attempt to get as close as possible
3013 to the remembered column position, so that the cursor tends to restrict
3014 itself to a vertical column as the user moves around in the edit buf‐
3015 fer. POSIX.1‐2008 requires conformance to historical practice, requir‐
3016 ing that the display location of the cursor on the display line be
3017 adjusted from the current column value as necessary to support this
3018 historical behavior.
3019 Historically, only a single line (and for some terminals, a single line
3021 minus 1 column) of characters could be entered by the user for the
3022 line-oriented commands; that is, :, !, /, or ?. POSIX.1‐2008 permits,
3023 but does not require, this limitation.
3024 Historically, ``soft'' errors in vi caused the terminal to be alerted,
3026 but no error message was displayed. As a general rule, no error mes‐
3027 sage was displayed for errors in command execution in vi, when the
3028 error resulted from the user attempting an invalid or impossible
3029 action, or when a searched-for object was not found. Examples of soft
3030 errors included h at the left margin, <control>‐B or [[ at the begin‐
3031 ning of the file, 2G at the end of the file, and so on. In addition,
3032 errors such as %, ]], }, ), N, n, f, F, t, and T failing to find the
3033 searched-for object were soft as well. Less consistently, / and ? dis‐
3034 played an error message if the pattern was not found, /, ?, N, and n
3035 displayed an error message if no previous regular expression had been
3036 specified, and ; did not display an error message if no previous f, F,
3037 t, or T command had occurred. Also, behavior in this area might reason‐
3038 ably be based on a runtime evaluation of the speed of a network connec‐
3039 tion. Finally, some implementations have provided error messages for
3040 soft errors in order to assist naive users, based on the value of a
3041 verbose edit option. POSIX.1‐2008 does not list specific errors for
3042 which an error message shall be displayed. Implementations should con‐
3043 form to historical practice in the absence of any strong reason to
3044 diverge.
3045 Page Backwards
3047 The <control>‐B and <control>‐F commands historically considered it an
3048 error to attempt to page past the beginning or end of the file, whereas
3049 the <control>‐D and <control>‐U commands simply moved to the beginning
3050 or end of the file. For consistency, POSIX.1‐2008 requires the latter
3051 behavior for all four commands. All four commands still consider it an
3052 error if the current line is at the beginning (<control>‐B, <con‐
3053 trol>‐U) or end (<control>‐F, <control>‐D) of the file. Historically,
3054 the <control>‐B and <control>‐F commands skip two lines in order to
3055 include overlapping lines when a single command is entered. This makes
3056 less sense in the presence of a count, as there will be, by definition,
3057 no overlapping lines. The actual calculation used by historical imple‐
3058 mentations of the vi editor for <control>‐B was:
3059 ((current first line) − count x (window edit option)) +2
3061 and for <control>‐F was:
3063 ((current first line) + count x (window edit option)) −2
3065 This calculation does not work well when intermixing commands with and
3067 without counts; for example, 3<control>‐F is not equivalent to entering
3068 the <control>‐F command three times, and is not reversible by entering
3069 the <control>‐B command three times. For consistency with other vi com‐
3070 mands that take counts, POSIX.1‐2008 requires a different calculation.
3071 Scroll Forward
3073 The 4BSD and System V implementations of vi differed on the initial
3074 value used by the scroll command. 4BSD used:
3075 ((window edit option) +1) /2
3077 while System V used the value of the scroll edit option. The System V
3079 version is specified by POSIX.1‐2008 because the standard developers
3080 believed that it was more intuitive and permitted the user a method of
3081 setting the scroll value initially without also setting the number of
3082 lines that are displayed.
3083 Scroll Forward by Line
3085 Historically, the <control>‐E and <control>‐Y commands considered it an
3086 error if the last and first lines, respectively, were already on the
3087 screen. POSIX.1‐2008 requires conformance to historical practice. His‐
3088 torically, the <control>‐E and <control>‐Y commands had no effect in
3089 open mode. For simplicity and consistency of specification,
3090 POSIX.1‐2008 requires that they behave as usual, albeit with a single
3091 line screen.
3092 Clear and Redisplay
3094 The historical <control>‐L command refreshed the screen exactly as it
3095 was supposed to be currently displayed, replacing any '@' characters
3096 for lines that had been deleted but not updated on the screen with
3097 refreshed '@' characters. The intent of the <control>‐L command is to
3098 refresh when the screen has been accidentally overwritten; for example,
3099 by a write command from another user, or modem noise.
3100 Redraw Screen
3102 The historical <control>‐R command redisplayed only when necessary to
3103 update lines that had been deleted but not updated on the screen and
3104 that were flagged with '@' characters. There is no requirement that the
3105 screen be in any way refreshed if no lines of this form are currently
3106 displayed. POSIX.1‐2008 permits implementations to extend this command
3107 to refresh lines on the screen flagged with '@' characters because they
3108 are too long to be displayed in the current framework; however, the
3109 current line and column need not be modified.
3110 Search for tagstring
3112 Historically, the first non-<blank> at or after the cursor was the
3113 first character, and all subsequent characters that were word charac‐
3114 ters, up to the end of the line, were included. For example, with the
3115 cursor on the leading <space> or on the '#' character in the text
3116 "#bar@", the tag was "#bar". On the character 'b' it was "bar", and on
3117 the 'a' it was "ar". POSIX.1‐2008 requires this behavior.
3118 Replace Text with Results from Shell Command
3120 Historically, the <, >, and ! commands considered most cursor motions
3121 other than line-oriented motions an error; for example, the command
3122 >/foo<CR> succeeded, while the command >l failed, even though the text
3123 region described by the two commands might be identical. For consis‐
3124 tency, all three commands only consider entire lines and not partial
3125 lines, and the region is defined as any line that contains a character
3126 that was specified by the motion.
3127 Move to Matching Character
3129 Other matching characters have been left implementation-defined in
3130 order to allow extensions such as matching '<' and '>' for searching
3131 HTML, or #ifdef, #else, and #endif for searching C source.
3132 Repeat Substitution
3134 POSIX.1‐2008 requires that any c and g flags specified to the previous
3135 substitute command be ignored; however, the r flag may still apply, if
3136 supported by the implementation.
3137 Return to Previous (Context or Section)
3139 The [[, ]], (, ), {, and } commands are all affected by ``section
3140 boundaries'', but in some historical implementations not all of the
3141 commands recognize the same section boundaries. This is a bug, not a
3142 feature, and a unique section-boundary algorithm was not described for
3143 each command. One special case that is preserved is that the sentence
3144 command moves to the end of the last line of the edit buffer while the
3145 other commands go to the beginning, in order to preserve the tradi‐
3146 tional character cut semantics of the sentence command. Historically,
3147 vi section boundaries at the beginning and end of the edit buffer were
3148 the first non-<blank> on the first and last lines of the edit buffer if
3149 one exists; otherwise, the last character of the first and last lines
3150 of the edit buffer if one exists. To increase consistency with other
3151 section locations, this has been simplified by POSIX.1‐2008 to the
3152 first character of the first and last lines of the edit buffer, or the
3153 first and the last lines of the edit buffer if they are empty.
3154 Sentence boundaries were problematic in the historical vi. They were
3156 not only the boundaries as defined for the section and paragraph com‐
3157 mands, but they were the first non-<blank> that occurred after those
3158 boundaries, as well. Historically, the vi section commands were docu‐
3159 mented as taking an optional window size as a count preceding the com‐
3160 mand. This was not implemented in historical versions, so POSIX.1‐2008
3161 requires that the count repeat the command, for consistency with other
3162 vi commands.
3163 Repeat
3165 Historically, mapped commands other than text input commands could not
3166 be repeated using the period command. POSIX.1‐2008 requires conformance
3167 to historical practice.
3168 The restrictions on the interpretation of special characters (for exam‐
3170 ple, <control>‐H) in the repetition of text input mode commands is
3171 intended to match historical practice. For example, given the input
3172 sequence:
3173 iab<control>-H<control>-H<control>-Hdef<escape>
3175 the user should be informed of an error when the sequence is first
3177 entered, but not during a command repetition. The character <control>‐T
3178 is specifically exempted from this restriction. Historical implementa‐
3179 tions of vi ignored <control>‐T characters that were input in the orig‐
3180 inal command during command repetition. POSIX.1‐2008 prohibits this
3181 behavior.
3182 Find Regular Expression
3184 Historically, commands did not affect the line searched to or from if
3185 the motion command was a search (/, ?, N, n) and the final position was
3186 the start/end of the line. There were some special cases and vi was not
3187 consistent. POSIX.1‐2008 does not permit this behavior, for consis‐
3188 tency. Historical implementations permitted but were unable to handle
3189 searches as motion commands that wrapped (that is, due to the edit
3190 option wrapscan) to the original location. POSIX.1‐2008 requires that
3191 this behavior be treated as an error.
3192 Historically, the syntax "/RE/0" was used to force the command to cut
3194 text in line mode. POSIX.1‐2008 requires conformance to historical
3195 practice.
3196 Historically, in open mode, a z specified to a search command redis‐
3198 played the current line instead of displaying the current screen with
3199 the current line highlighted. For consistency and simplicity of speci‐
3200 fication, POSIX.1‐2008 does not permit this behavior.
3201 Historically, trailing z commands were permitted and ignored if entered
3203 as part of a search used as a motion command. For consistency and sim‐
3204 plicity of specification, POSIX.1‐2008 does not permit this behavior.
3205 Execute an ex Command
3207 Historically, vi implementations restricted the commands that could be
3208 entered on the colon command line (for example, append and change), and
3209 some other commands were known to cause them to fail catastrophically.
3210 For consistency, POSIX.1‐2008 does not permit these restrictions. When
3211 executing an ex command by entering :, it is not possible to enter a
3212 <newline> as part of the command because it is considered the end of
3213 the command. A different approach is to enter ex command mode by using
3214 the vi Q command (and later resuming visual mode with the ex vi com‐
3215 mand). In ex command mode, the single-line limitation does not exist.
3216 So, for example, the following is valid:
3217 Q
3219 s/break here/break\
3220 here/
3221 vi
3222 POSIX.1‐2008 requires that, if the ex command overwrites any part of
3224 the screen that would be erased by a refresh, vi pauses for a character
3225 from the user. Historically, this character could be any character; for
3226 example, a character input by the user before the message appeared, or
3227 even a mapped character. This is probably a bug, but implementations
3228 that have tried to be more rigorous by requiring that the user enter a
3229 specific character, or that the user enter a character after the mes‐
3230 sage was displayed, have been forced by user indignation back into his‐
3231 torical behavior. POSIX.1‐2008 requires conformance to historical prac‐
3232 tice.
3233 Shift Left (Right)
3235 Refer to the Rationale for the ! and / commands. Historically, the <
3236 and > commands sometimes moved the cursor to the first non-<blank> (for
3237 example if the command was repeated or with _ as the motion command),
3238 and sometimes left it unchanged. POSIX.1‐2008 does not permit this
3239 inconsistency, requiring instead that the cursor always move to the
3240 first non-<blank>. Historically, the < and > commands did not support
3241 buffer arguments, although some implementations allow the specification
3242 of an optional buffer. This behavior is neither required nor disallowed
3243 by POSIX.1‐2008.
3244 Execute
3246 Historically, buffers could execute other buffers, and loops, infinite
3247 and otherwise, were possible. POSIX.1‐2008 requires conformance to his‐
3248 torical practice. The *buffer syntax of ex is not required in vi,
3249 because it is not historical practice and has been used in some vi
3250 implementations to support additional scripting languages.
3251 Reverse Case
3253 Historically, the ~ command ignored any associated count, and acted
3254 only on the characters in the current line. For consistency with other
3255 vi commands, POSIX.1‐2008 requires that an associated count act on the
3256 next count characters, and that the command move to subsequent lines if
3257 warranted by count, to make it possible to modify large pieces of text
3258 in a reasonably efficient manner. There exist vi implementations that
3259 optionally require an associated motion command for the ~ command.
3260 Implementations supporting this functionality are encouraged to base it
3261 on the tildedop edit option and handle the text regions and cursor
3262 positioning identically to the yank command.
3263 Append
3265 Historically, counts specified to the A, a, I, and i commands repeated
3266 the input of the first line count times, and did not repeat the subse‐
3267 quent lines of the input text. POSIX.1‐2008 requires that the entire
3268 text input be repeated count times.
3269 Move Backward to Preceding Word
3271 Historically, vi became confused if word commands were used as motion
3272 commands in empty files. POSIX.1‐2008 requires that this be an error.
3273 Historical implementations of vi had a large number of bugs in the word
3274 movement commands, and they varied greatly in behavior in the presence
3275 of empty lines, ``words'' made up of a single character, and lines con‐
3276 taining only <blank> characters. For consistency and simplicity of
3277 specification, POSIX.1‐2008 does not permit this behavior.
3278 Change to End-of-Line
3280 Some historical implementations of the C command did not behave as
3281 described by POSIX.1‐2008 when the $ key was remapped because they were
3282 implemented by pushing the $ key onto the input queue and reprocessing
3283 it. POSIX.1‐2008 does not permit this behavior. Historically, the C, S,
3284 and s commands did not copy replaced text into the numeric buffers. For
3285 consistency and simplicity of specification, POSIX.1‐2008 requires that
3286 they behave like their respective c commands in all respects.
3287 Delete
3289 Historically, lines in open mode that were deleted were scrolled up,
3290 and an @ glyph written over the beginning of the line. In the case of
3291 terminals that are incapable of the necessary cursor motions, the edi‐
3292 tor erased the deleted line from the screen. POSIX.1‐2008 requires con‐
3293 formance to historical practice; that is, if the terminal cannot dis‐
3294 play the '@' character, the line cannot remain on the screen.
3295 Delete to End-of-Line
3297 Some historical implementations of the D command did not behave as
3298 described by POSIX.1‐2008 when the $ key was remapped because they were
3299 implemented by pushing the $ key onto the input queue and reprocessing
3300 it. POSIX.1‐2008 does not permit this behavior.
3301 Join
3303 An historical oddity of vi is that the commands J, 1J, and 2J are all
3304 equivalent. POSIX.1‐2008 requires conformance to historical practice.
3305 The vi J command is specified in terms of the ex join command with an
3306 ex command count value. The address correction for a count that is past
3307 the end of the edit buffer is necessary for historical compatibility
3308 for both ex and vi.
3309 Mark Position
3311 Historical practice is that only lowercase letters, plus backquote and
3312 single-quote, could be used to mark a cursor position. POSIX.1‐2008
3313 requires conformance to historical practice, but encourages implementa‐
3314 tions to support other characters as marks as well.
3315 Repeat Regular Expression Find (Forward and Reverse)
3317 Historically, the N and n commands could not be used as motion compo‐
3318 nents for the c command. With the exception of the cN command, which
3319 worked if the search crossed a line boundary, the text region would be
3320 discarded, and the user would not be in text input mode. For consis‐
3321 tency and simplicity of specification, POSIX.1‐2008 does not permit
3322 this behavior.
3323 Insert Empty Line (Below and Above)
3325 Historically, counts to the O and o commands were used as the number of
3326 physical lines to open, if the terminal was dumb and the slowopen
3327 option was not set. This was intended to minimize traffic over slow
3328 connections and repainting for dumb terminals. POSIX.1‐2008 does not
3329 permit this behavior, requiring that a count to the open command behave
3330 as for other text input commands. This change to historical practice
3331 was made for consistency, and because a superset of the functionality
3332 is provided by the slowopen edit option.
3333 Put from Buffer (Following and Before)
3335 Historically, counts to the p and P commands were ignored if the buffer
3336 was a line mode buffer, but were (mostly) implemented as described in
3337 POSIX.1‐2008 if the buffer was a character mode buffer. Because imple‐
3338 mentations exist that do not have this limitation, and because pasting
3339 lines multiple times is generally useful, POSIX.1‐2008 requires that
3340 count be supported for all p and P commands.
3341 Historical implementations of vi were widely known to have major prob‐
3343 lems in the p and P commands, particularly when unusual regions of text
3344 were copied into the edit buffer. The standard developers viewed these
3345 as bugs, and they are not permitted for consistency and simplicity of
3346 specification.
3347 Historically, a P or p command (or an ex put command executed from open
3349 or visual mode) executed in an empty file, left an empty line as the
3350 first line of the file. For consistency and simplicity of specifica‐
3351 tion, POSIX.1‐2008 does not permit this behavior.
3352 Replace Character
3354 Historically, the r command did not correctly handle the erase and word
3355 erase characters as arguments, nor did it handle an associated count
3356 greater than 1 with a <carriage-return> argument, for which it replaced
3357 count characters with a single <newline>. POSIX.1‐2008 does not permit
3358 these inconsistencies.
3359 Historically, the r command permitted the <control>‐V escaping of
3361 entered characters, such as <ESC> and the <carriage-return>; however,
3362 it required two leading <control>‐V characters instead of one.
3363 POSIX.1‐2008 requires that this be changed for consistency with the
3364 other text input commands of vi.
3365 Historically, it is an error to enter the r command if there are less
3367 than count characters at or after the cursor in the line. While a rea‐
3368 sonable and unambiguous extension would be to permit the r command on
3369 empty lines, it would require that too large a count be adjusted to
3370 match the number of characters at or after the cursor for consistency,
3371 which is sufficiently different from historical practice to be avoided.
3372 POSIX.1‐2008 requires conformance to historical practice.
3373 Replace Characters
3375 Historically, if there were autoindent characters in the line on which
3376 the R command was run, and autoindent was set, the first <newline>
3377 would be properly indented and no characters would be replaced by the
3378 <newline>. Each additional <newline> would replace n characters, where
3379 n was the number of characters that were needed to indent the rest of
3380 the line to the proper indentation level. This behavior is a bug and is
3381 not permitted by POSIX.1‐2008.
3382 Undo
3384 Historical practice for cursor positioning after undoing commands was
3385 mixed. In most cases, when undoing commands that affected a single
3386 line, the cursor was moved to the start of added or changed text, or
3387 immediately after deleted text. However, if the user had moved from the
3388 line being changed, the column was either set to the first non-<blank>,
3389 returned to the origin of the command, or remained unchanged. When
3390 undoing commands that affected multiple lines or entire lines, the cur‐
3391 sor was moved to the first character in the first line restored. As an
3392 example of how inconsistent this was, a search, followed by an o text
3393 input command, followed by an undo would return the cursor to the loca‐
3394 tion where the o command was entered, but a cw command followed by an o
3395 command followed by an undo would return the cursor to the first
3396 non-<blank> of the line. POSIX.1‐2008 requires the most useful of these
3397 behaviors, and discards the least useful, in the interest of consis‐
3398 tency and simplicity of specification.
3399 Yank
3401 Historically, the yank command did not move to the end of the motion if
3402 the motion was in the forward direction. It moved to the end of the
3403 motion if the motion was in the backward direction, except for the _
3404 command, or for the G and ' commands when the end of the motion was on
3405 the current line. This was further complicated by the fact that for a
3406 number of motion commands, the yank command moved the cursor but did
3407 not update the screen; for example, a subsequent command would move the
3408 cursor from the end of the motion, even though the cursor on the screen
3409 had not reflected the cursor movement for the yank command.
3410 POSIX.1‐2008 requires that all yank commands associated with backward
3411 motions move the cursor to the end of the motion for consistency, and
3412 specifically, to make ' commands as motions consistent with search pat‐
3413 terns as motions.
3414 Yank Current Line
3416 Some historical implementations of the Y command did not behave as
3417 described by POSIX.1‐2008 when the '_' key was remapped because they
3418 were implemented by pushing the '_' key onto the input queue and repro‐
3419 cessing it. POSIX.1‐2008 does not permit this behavior.
3420 Redraw Window
3422 Historically, the z command always redrew the screen. This is permitted
3423 but not required by POSIX.1‐2008, because of the frequent use of the z
3424 command in macros such as map n nz. for screen positioning, instead of
3425 its use to change the screen size. The standard developers believed
3426 that expanding or scrolling the screen offered a better interface for
3427 users. The ability to redraw the screen is preserved if the optional
3428 new window size is specified, and in the <control>‐L and <control>‐R
3429 commands.
3430 The semantics of z^ are confusing at best. Historical practice is that
3432 the screen before the screen that ended with the specified line is dis‐
3433 played. POSIX.1‐2008 requires conformance to historical practice.
3434 Historically, the z command would not display a partial line at the top
3436 or bottom of the screen. If the partial line would normally have been
3437 displayed at the bottom of the screen, the command worked, but the par‐
3438 tial line was replaced with '@' characters. If the partial line would
3439 normally have been displayed at the top of the screen, the command
3440 would fail. For consistency and simplicity of specification,
3441 POSIX.1‐2008 does not permit this behavior.
3442 Historically, the z command with a line specification of 1 ignored the
3444 command. For consistency and simplicity of specification, POSIX.1‐2008
3445 does not permit this behavior.
3446 Historically, the z command did not set the cursor column to the first
3448 non-<blank> for the character if the first screen was to be displayed,
3449 and was already displayed. For consistency and simplicity of specifica‐
3450 tion, POSIX.1‐2008 does not permit this behavior.
3451 Input Mode Commands in vi
3453 Historical implementations of vi did not permit the user to erase more
3454 than a single line of input, or to use normal erase characters such as
3455 line erase, worderase, and erase to erase autoindent characters. As
3456 there exist implementations of vi that do not have these limitations,
3457 both behaviors are permitted, but only historical practice is required.
3458 In the case of these extensions, vi is required to pause at the autoin‐
3459 dent and previous line boundaries.
3460 Historical implementations of vi updated only the portion of the screen
3462 where the current cursor character was displayed. For example, consider
3463 the vi input keystrokes:
3464 iabcd<escape>0C<tab>
3466 Historically, the <tab> would overwrite the characters "abcd" when it
3468 was displayed. Other implementations replace only the 'a' character
3469 with the <tab>, and then push the rest of the characters ahead of the
3470 cursor. Both implementations have problems. The historical implementa‐
3471 tion is probably visually nicer for the above example; however, for the
3472 keystrokes:
3473 iabcd<ESC>0R<tab><ESC>
3475 the historical implementation results in the string "bcd" disappearing
3477 and then magically reappearing when the <ESC> character is entered.
3478 POSIX.1‐2008 requires the former behavior when overwriting erase-col‐
3479 umns—that is, overwriting characters that are no longer logically part
3480 of the edit buffer—and the latter behavior otherwise.
3481 Historical implementations of vi discarded the <control>‐D and <con‐
3483 trol>‐T characters when they were entered at places where their command
3484 functionality was not appropriate. POSIX.1‐2008 requires that the <con‐
3485 trol>‐T functionality always be available, and that <control>‐D be
3486 treated as any other key when not operating on autoindent characters.
3487 NUL
3489 Some historical implementations of vi limited the number of characters
3490 entered using the NUL input character to 256 bytes. POSIX.1‐2008 per‐
3491 mits this limitation; however, implementations are encouraged to remove
3492 this limit.
3493 <control>‐D
3495 See also Rationale for the input mode command <newline>. The hidden
3496 assumptions in the <control>‐D command (and in the vi autoindent speci‐
3497 fication in general) is that <space> characters take up a single column
3498 on the screen and that <tab> characters are comprised of an integral
3499 number of <space> characters.
3500 <newline>
3502 Implementations are permitted to rewrite autoindent characters in the
3503 line when <newline>, <carriage-return>, <control>‐D, and <control>‐T
3504 are entered, or when the shift commands are used, because historical
3505 implementations have both done so and found it necessary to do so. For
3506 example, a <control>‐D when the cursor is preceded by a single <tab>,
3507 with tabstop set to 8, and shiftwidth set to 3, will result in the
3508 <tab> being replaced by several <space> characters.
3509 <control>‐T
3511 See also the Rationale for the input mode command <newline>. Histori‐
3512 cally, <control>‐T only worked if no non-<blank> characters had yet
3513 been input in the current input line. In addition, the characters
3514 inserted by <control>‐T were treated as autoindent characters, and
3515 could not be erased using normal user erase characters. Because imple‐
3516 mentations exist that do not have these limitations, and as moving to a
3517 column boundary is generally useful, POSIX.1‐2008 requires that both
3518 limitations be removed.
3519 <control>‐V
3521 Historically, vi used ^V, regardless of the value of the literal-next
3522 character of the terminal. POSIX.1‐2008 requires conformance to his‐
3523 torical practice.
3524 The uses described for <control>‐V can also be accomplished with <con‐
3526 trol>‐Q, which is useful on terminals that use <control>‐V for the
3527 down-arrow function. However, most historical implementations use <con‐
3528 trol>‐Q for the termios START character, so the editor will generally
3529 not receive the <control>‐Q unless stty ixon mode is set to off. (In
3530 addition, some historical implementations of vi explicitly set ixon
3531 mode to on, so it was difficult for the user to set it to off.) Any of
3532 the command characters described in POSIX.1‐2008 can be made ineffec‐
3533 tive by their selection as termios control characters, using the stty
3534 utility or other methods described in the System Interfaces volume of
3535 POSIX.1‐2008.
3536 <ESC>
3538 Historically, SIGINT alerted the terminal when used to end input mode.
3539 This behavior is permitted, but not required, by POSIX.1‐2008.
3540
3542 None.
3543
3545 ed, ex, stty
3546 The Base Definitions volume of POSIX.1‐2008, Section 12.2, Utility Syn‐
3548 tax Guidelines
3549
3551 Portions of this text are reprinted and reproduced in electronic form
3552 from IEEE Std 1003.1, 2013 Edition, Standard for Information Technology
3553 -- Portable Operating System Interface (POSIX), The Open Group Base
3554 Specifications Issue 7, Copyright (C) 2013 by the Institute of Electri‐
3555 cal and Electronics Engineers, Inc and The Open Group. (This is
3556 POSIX.1-2008 with the 2013 Technical Corrigendum 1 applied.) In the
3557 event of any discrepancy between this version and the original IEEE and
3558 The Open Group Standard, the original IEEE and The Open Group Standard
3559 is the referee document. The original Standard can be obtained online
3560 at http://www.unix.org/online.html .
3561 Any typographical or formatting errors that appear in this page are
3563 most likely to have been introduced during the conversion of the source
3564 files to man page format. To report such errors, see https://www.ker‐
3565 nel.org/doc/man-pages/reporting_bugs.html .
3566IEEE/The Open Group 2013 VI(1P)