1VI(P) POSIX Programmer's Manual VI(P)
2
6 vi - screen-oriented (visual) display editor
7
9 vi [-rR][-c command][-t tagstring][-w size][file ...]
10
12 This utility shall be provided on systems that both support the User
13 Portability Utilities option and define the POSIX2_CHAR_TERM symbol. On
14 other systems it is optional.
15 The vi (visual) utility is a screen-oriented text editor. Only the open
17 and visual modes of the editor are described in IEEE Std 1003.1-2001;
18 see the line editor ex for additional editing capabilities used in vi.
19 The user can switch back and forth between vi and ex and execute ex
20 commands from within vi.
21 This reference page uses the term edit buffer to describe the current
23 working text. No specific implementation is implied by this term. All
24 editing changes are performed on the edit buffer, and no changes to it
25 shall affect any file until an editor command writes the file.
26 When using vi, the terminal screen acts as a window into the editing
28 buffer. Changes made to the editing buffer shall be reflected in the
29 screen display; the position of the cursor on the screen shall indicate
30 the position within the editing buffer.
31 Certain terminals do not have all the capabilities necessary to support
33 the complete vi definition. When these commands cannot be supported on
34 such terminals, this condition shall not produce an error message such
35 as "not an editor command" or report a syntax error. The implementation
36 may either accept the commands and produce results on the screen that
37 are the result of an unsuccessful attempt to meet the requirements of
38 this volume of IEEE Std 1003.1-2001 or report an error describing the
39 terminal-related deficiency.
40
42 The vi utility shall conform to the Base Definitions volume of
43 IEEE Std 1003.1-2001, Section 12.2, Utility Syntax Guidelines.
44 The following options shall be supported:
46 -c command
48 See the ex command description of the -c option.
49 -r See the ex command description of the -r option.
51 -R See the ex command description of the -R option.
53 -t tagstring
55 See the ex command description of the -t option.
56 -w size
58 See the ex command description of the -w option.
59
62 See the OPERANDS section of the ex command for a description of the op‐
63 erands supported by the vi command.
64
66 If standard input is not a terminal device, the results are undefined.
67 The standard input consists of a series of commands and input text, as
68 described in the EXTENDED DESCRIPTION section.
69 If a read from the standard input returns an error, or if the editor
71 detects an end-of-file condition from the standard input, it shall be
72 equivalent to a SIGHUP asynchronous event.
73
75 See the INPUT FILES section of the ex command for a description of the
76 input files supported by the vi command.
77
79 See the ENVIRONMENT VARIABLES section of the ex command for the envi‐
80 ronment variables that affect the execution of the vi command.
81
83 See the ASYNCHRONOUS EVENTS section of the ex for the asynchronous
84 events that affect the execution of the vi command.
85
87 If standard output is not a terminal device, undefined results occur.
88 Standard output may be used for writing prompts to the user, for infor‐
90 mational messages, and for writing lines from the file.
91
93 If standard output is not a terminal device, undefined results occur.
94 The standard error shall be used only for diagnostic messages.
96
98 See the OUTPUT FILES section of the ex command for a description of the
99 output files supported by the vi command.
100
102 If the terminal does not have the capabilities necessary to support an
103 unspecified portion of the vi definition, implementations shall start
104 initially in ex mode or open mode. Otherwise, after initialization, vi
105 shall be in command mode; text input mode can be entered by one of sev‐
106 eral commands used to insert or change text. In text input mode, <ESC>
107 can be used to return to command mode; other uses of <ESC> are
108 described later in this section; see Terminate Command or Input Mode .
109 Initialization in ex and vi
111 See Initialization in ex and vi for a description of ex and vi initial‐
112 ization for the vi utility.
113 Command Descriptions in vi
115 The following symbols are used in this reference page to represent
116 arguments to commands.
117 buffer See the description of buffer in the EXTENDED DESCRIPTION sec‐
119 tion of the ex utility; see Command Descriptions in ex .
120 In open and visual mode, when a command synopsis shows both [ buffer]
122 and [ count] preceding the command name, they can be specified in
123 either order.
124 count A positive integer used as an optional argument to most com‐
126 mands, either to give a repeat count or as a size. This argument
127 is optional and shall default to 1 unless otherwise specified.
128 The Synopsis lines for the vi commands <control>-G, <control>-L, <con‐
130 trol>-R, <control>-], %, &, ^, D, m, M, Q, u, U, and ZZ do not have
131 count as an optional argument. Regardless, it shall not be an error to
132 specify a count to these commands, and any specified count shall be
133 ignored.
134 motion An optional trailing argument used by the !, <, >, c, d, and y
136 commands, which is used to indicate the region of text that
137 shall be affected by the command. The motion can be either one
138 of the command characters repeated or one of several other vi
139 commands (listed in the following table). Each of the applicable
140 commands specifies the region of text matched by repeating the
141 command; each command that can be used as a motion command spec‐
142 ifies the region of text it affects.
143 Commands that take motion arguments operate on either lines or charac‐
145 ters, depending on the circumstances. When operating on lines, all
146 lines that fall partially or wholly within the text region specified
147 for the command shall be affected. When operating on characters, only
148 the exact characters in the specified text region shall be affected.
149 Each motion command specifies this individually.
150 When commands that may be motion commands are not used as motion com‐
152 mands, they shall set the current position to the current line and col‐
153 umn as specified.
154 The following commands shall be valid cursor motion commands:
156 <apostrophe> ( - j H
159 <carriage-return> ) $ k L
160 <comma> [[ % l M
161 <control>-H ]] _ n N
162 <control>-N { ; t T
163 <control>-P } ? w W
164 <grave accent> ^ b B
165 <newline> + e E
166 <space> | f F
167 <zero> / h G
168 Any count that is specified to a command that has an associated motion
170 command shall be applied to the motion command. If a count is applied
171 to both the command and its associated motion command, the effect shall
172 be multiplicative.
173 The following symbols are used in this section to specify locations in
176 the edit buffer:
177 current character
179 The character that is currently indicated by the cursor.
181 end of a line
183 The point located between the last non- <newline> (if any) and
185 the terminating <newline> of a line. For an empty line, this
186 location coincides with the beginning of the line.
187 end of the edit buffer
189 The location corresponding to the end of the last line in the
191 edit buffer.
192 The following symbols are used in this section to specify command
195 actions:
196 bigword
198 In the POSIX locale, vi shall recognize four kinds of bigwords:
199 1. A maximal sequence of non- <blank>s preceded and followed by
201 <blank>s or the beginning or end of a line or the edit buf‐
202 fer
203 2. One or more sequential blank lines
205 3. The first character in the edit buffer
207 4. The last non- <newline> in the edit buffer
209 word In the POSIX locale, vi shall recognize five kinds of words:
211 1. A maximal sequence of letters, digits, and underscores,
213 delimited at both ends by:
214 * Characters other than letters, digits, or underscores
216 * The beginning or end of a line
218 * The beginning or end of the edit buffer
220 2. A maximal sequence of characters other than letters, digits,
222 underscores, or <blank>s, delimited at both ends by:
223 * A letter, digit, underscore
225 * <blank>s
227 * The beginning or end of a line
229 * The beginning or end of the edit buffer
231 3. One or more sequential blank lines
233 4. The first character in the edit buffer
235 5. The last non- <newline> in the edit buffer
237 section boundary
239 A section boundary is one of the following:
241 1. A line whose first character is a <form-feed>
243 2. A line whose first character is an open curly brace ( '{' )
245 3. A line whose first character is a period and whose second
247 and third characters match a two-character pair in the sec‐
248 tions edit option (see ed)
249 4. A line whose first character is a period and whose only
251 other character matches the first character of a two-charac‐
252 ter pair in the sections edit option, where the second char‐
253 acter of the two-character pair is a <space>
254 5. The first line of the edit buffer
256 6. The last line of the edit buffer if the last line of the
258 edit buffer is empty or if it is a ]] or } command; other‐
259 wise, the last non- <newline> of the last line of the edit
260 buffer
261 paragraph boundary
263 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 para‐
270 graphs 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-charac‐
274 ter 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.
282 sentence boundary
284 A sentence boundary is one of the following:
286 1. A paragraph boundary
288 2. The first non- <blank> that occurs after a paragraph bound‐
290 ary
291 3. The first non- <blank> that occurs after a period ( '.' ),
293 exclamation mark ( '!' ), or question mark ( '?' ), followed
294 by two <space>s or the end of a line; any number of closing
295 parenthesis ( ')' ), closing brackets ( ']' ), double quote
296 ( ' ),' or single quote ( '" ) characters can appear between
297 the punctuation mark and the two <space>s or end-of-line
298 In the remainder of the description of the vi utility, the term "buffer
300 line" refers to a line in the edit buffer and the term "display line"
301 refers to the line or lines on the display screen used to display one
302 buffer line. The term "current line" refers to a specific "buffer
303 line".
304 If there are display lines on the screen for which there are no corre‐
306 sponding buffer lines because they correspond to lines that would be
307 after the end of the file, they shall be displayed as a single tilde (
308 '~' ) character, plus the terminating <newline>.
309 The last line of the screen shall be used to report errors or display
311 informational messages. It shall also be used to display the input for
312 "line-oriented commands" ( /, ?, :, and !). When a line-oriented com‐
313 mand is executed, the editor shall enter text input mode on the last
314 line on the screen, using the respective command characters as prompt
315 characters. (In the case of the ! command, the associated motion shall
316 be entered by the user before the editor enters text input mode.) The
317 line entered by the user shall be terminated by a <newline>, a non-
318 <control>-V-escaped <carriage-return>, or unescaped <ESC>. It is
319 unspecified if more characters than require a display width minus one
320 column number of screen columns can be entered.
321 If any command is executed that overwrites a portion of the screen
323 other than the last line of the screen (for example, the ex suspend or
324 ! commands), other than the ex shell command, the user shall be
325 prompted for a character before the screen is refreshed and the edit
326 session continued.
327 <tab>s shall take up the number of columns on the screen set by the
329 tabstop edit option (see ed), unless there are less than that number of
330 columns before the display margin that will cause the displayed line to
331 be folded; in this case, they shall only take up the number of columns
332 up to that boundary.
333 The cursor shall be placed on the current line and relative to the cur‐
335 rent column as specified by each command described in the following
336 sections.
337 In open mode, if the current line is not already displayed, then it
339 shall be displayed.
340 In visual mode, if the current line is not displayed, then the lines
342 that are displayed shall be expanded, scrolled, or redrawn to cause an
343 unspecified portion of the current line to be displayed. If the screen
344 is redrawn, no more than the number of display lines specified by the
345 value of the window edit option shall be displayed (unless the current
346 line cannot be completely displayed in the number of display lines
347 specified by the window edit option) and the current line shall be
348 positioned as close to the center of the displayed lines as possible
349 (within the constraints imposed by the distance of the line from the
350 beginning or end of the edit buffer). If the current line is before the
351 first line in the display and the screen is scrolled, an unspecified
352 portion of the current line shall be placed on the first line of the
353 display. If the current line is after the last line in the display and
354 the screen is scrolled, an unspecified portion of the current line
355 shall be placed on the last line of the display.
356 In visual mode, if a line from the edit buffer (other than the current
358 line) does not entirely fit into the lines at the bottom of the display
359 that are available for its presentation, the editor may choose not to
360 display any portion of the line. The lines of the display that do not
361 contain text from the edit buffer for this reason shall each consist of
362 a single '@' character.
363 In visual mode, the editor may choose for unspecified reasons to not
365 update lines in the display to correspond to the underlying edit buffer
366 text. The lines of the display that do not correctly correspond to text
367 from the edit buffer for this reason shall consist of a single '@'
368 character (plus the terminating <newline>), and the <control>-R command
369 shall cause the editor to update the screen to correctly represent the
370 edit buffer.
371 Open and visual mode commands that set the current column set it to a
373 column position in the display, and not a character position in the
374 line. In this case, however, the column position in the display shall
375 be calculated for an infinite width display; for example, the column
376 related to a character that is part of a line that has been folded onto
377 additional screen lines will be offset from the display line column
378 where the buffer line begins, not from the beginning of a particular
379 display line.
380 The display cursor column in the display is based on the value of the
382 current column, as follows, with each rule applied in turn:
383 1. If the current column is after the last display line column used by
385 the displayed line, the display cursor column shall be set to the
386 last display line column occupied by the last non- <newline> in the
387 current line; otherwise, the display cursor column shall be set to
388 the current column.
389 2. If the character of which some portion is displayed in the display
391 line column specified by the display cursor column requires more
392 than a single display line column:
393 a. If in text input mode, the display cursor column shall be
395 adjusted to the first display line column in which any portion
396 of that character is displayed.
397 b. Otherwise, the display cursor column shall be adjusted to the
399 last display line column in which any portion of that character
400 is displayed.
401 The current column shall not be changed by these adjustments to the
403 display cursor column.
404 If an error occurs during the parsing or execution of a vi command:
406 * The terminal shall be alerted. Execution of the vi command shall
408 stop, and the cursor (for example, the current line and column)
409 shall not be further modified.
410 * Unless otherwise specified by the following command sections, it is
412 unspecified whether an informational message shall be displayed.
413 * Any partially entered vi command shall be discarded.
415 * If the vi command resulted from a map expansion, all characters from
417 that map expansion shall be discarded, except as otherwise specified
418 by the map command (see ed).
419 * If the vi command resulted from the execution of a buffer, no fur‐
421 ther commands caused by the execution of the buffer shall be exe‐
422 cuted.
423 Page Backwards
425 Synopsis:
426 [count] <control>-B
429 If in open mode, the <control>-B command shall behave identically to
432 the z command. Otherwise, if the current line is the first line of the
433 edit buffer, it shall be an error.
434 If the window edit option is less than 3, display a screen where the
436 last line of the display shall be some portion of:
437 (current first line) -1
440 otherwise, display a screen where the first line of the display shall
442 be some portion of:
443 (current first line) - count x ((window edit option) -2)
446 If this calculation would result in a line that is before the first
448 line of the edit buffer, the first line of the display shall display
449 some portion of the first line of the edit buffer.
450 Current line: If no lines from the previous display remain on the
452 screen, set to the last line of the display; otherwise, set to ( line -
453 the number of new lines displayed on this screen).
454 Current column: Set to non- <blank>.
456 Scroll Forward
458 Synopsis:
459 [count] <control>-D
462 If the current line is the last line of the edit buffer, it shall be an
465 error.
466 If no count is specified, count shall default to the count associated
468 with the previous <control>-D or <control>-U command. If there was no
469 previous <control>-D or <control>-U command, count shall default to the
470 value of the scroll edit option.
471 If in open mode, write lines starting with the line after the current
473 line, until count lines or the last line of the file have been written.
474 Current line: If the current line + count is past the last line of the
476 edit buffer, set to the last line of the edit buffer; otherwise, set to
477 the current line + count.
478 Current column: Set to non- <blank>.
480 Scroll Forward by Line
482 Synopsis:
483 [count] <control>-E
486 Display the line count lines after the last line currently displayed.
489 If the last line of the edit buffer is displayed, it shall be an error.
491 If there is no line count lines after the last line currently dis‐
492 played, the last line of the display shall display some portion of the
493 last line of the edit buffer.
494 Current line: Unchanged if the previous current character is displayed;
496 otherwise, set to the first line displayed.
497 Current column: Unchanged.
499 Page Forward
501 Synopsis:
502 [count] <control>-F
505 If in open mode, the <control>-F command shall behave identically to
508 the z command. Otherwise, if the current line is the last line of the
509 edit buffer, it shall be an error.
510 If the window edit option is less than 3, display a screen where the
512 first line of the display shall be some portion of:
513 (current last line) +1
516 otherwise, display a screen where the first line of the display shall
518 be some portion of:
519 (current first line) + count x ((window edit option) -2)
522 If this calculation would result in a line that is after the last line
524 of the edit buffer, the last line of the display shall display some
525 portion of the last line of the edit buffer.
526 Current line: If no lines from the previous display remain on the
528 screen, set to the first line of the display; otherwise, set to ( line
529 + the number of new lines displayed on this screen).
530 Current column: Set to non- <blank>.
532 Display Information
534 Synopsis:
535 <control>-G
538 This command shall be equivalent to the ex file command.
541 Move Cursor Backwards
543 Synopsis:
544 [count] <control>-H
547 [count] h
550 the current erase character (see stty)
553 If there are no characters before the current character on the current
556 line, it shall be an error. If there are less than count previous char‐
557 acters on the current line, count shall be adjusted to the number of
558 previous characters on the line.
559 If used as a motion command:
561 1. The text region shall be from the character before the starting
563 cursor up to and including the countth character before the start‐
564 ing cursor.
565 2. Any text copied to a buffer shall be in character mode.
567 If not used as a motion command:
569 Current line: Unchanged.
571 Current column: Set to ( column - the number of columns occupied by
573 count characters ending with the previous current column).
574 Move Down
576 Synopsis:
577 [count] <newline>
580 [count] <control>-J
583 [count] <control>-M
586 [count] <control>-N
589 [count] j
592 [count] <carriage-return>
595 [count] +
598 If there are less than count lines after the current line in the edit
601 buffer, it shall be an error.
602 If used as a motion command:
604 1. The text region shall include the starting line and the next count
606 - 1 lines.
607 2. Any text copied to a buffer shall be in line mode.
609 If not used as a motion command:
611 Current line: Set to current line+ count.
613 Current column: Set to non- <blank> for the <carriage-return>, <con‐
615 trol>-M, and + commands; otherwise, unchanged.
616 Clear and Redisplay
618 Synopsis:
619 <control>-L
622 If in open mode, clear the screen and redisplay the current line. Oth‐
625 erwise, clear and redisplay the screen.
626 Current line: Unchanged.
628 Current column: Unchanged.
630 Move Up
632 Synopsis:
633 [count] <control>-P
636 [count] k
639 [count] -
642 If there are less than count lines before the current line in the edit
645 buffer, it shall be an error.
646 If used as a motion command:
648 1. The text region shall include the starting line and the previous
650 count lines.
651 2. Any text copied to a buffer shall be in line mode.
653 If not used as a motion command:
655 Current line: Set to current line - count.
657 Current column: Set to non- <blank> for the - command; otherwise,
659 unchanged.
660 Redraw Screen
662 Synopsis:
663 <control>-R
666 If any lines have been deleted from the display screen and flagged as
669 deleted on the terminal using the @ convention (see the beginning of
670 the EXTENDED DESCRIPTION section), they shall be redisplayed to match
671 the contents of the edit buffer.
672 It is unspecified whether lines flagged with @ because they do not fit
674 on the terminal display shall be affected.
675 Current line: Unchanged.
677 Current column: Unchanged.
679 Scroll Backward
681 Synopsis:
682 [count] <control>-U
685 If the current line is the first line of the edit buffer, it shall be
688 an error.
689 If no count is specified, count shall default to the count associated
691 with the previous <control>-D or <control>-U command. If there was no
692 previous <control>-D or <control>-U command, count shall default to the
693 value of the scroll edit option.
694 Current line: If count is greater than the current line, set to 1; oth‐
696 erwise, set to the current line - count.
697 Current column: Set to non- <blank>.
699 Scroll Backward by Line
701 Synopsis:
702 [count] <control>-Y
705 Display the line count lines before the first line currently displayed.
708 If the current line is the first line of the edit buffer, it shall be
710 an error. If this calculation would result in a line that is before the
711 first line of the edit buffer, the first line of the display shall dis‐
712 play some portion of the first line of the edit buffer.
713 Current line: Unchanged if the previous current character is displayed;
715 otherwise, set to the first line displayed.
716 Current column: Unchanged.
718 Edit the Alternate File
720 Synopsis:
721 <control>-^
724 This command shall be equivalent to the ex edit command, with the
726 alternate pathname as its argument.
727 Terminate Command or Input Mode
729 Synopsis:
730 <ESC>
733 If a partial vi command (as defined by at least one, non- count charac‐
736 ter) has been entered, discard the count and the command character(s).
737 Otherwise, if no command characters have been entered, and the <ESC>
739 was the result of a map expansion, the terminal shall be alerted and
740 the <ESC> character shall be discarded, but it shall not be an error.
741 Otherwise, it shall be an error.
743 Current line: Unchanged.
745 Current column: Unchanged.
747 Search for tagstring
749 Synopsis:
750 <control>-]
753 If the current character is not a word or <blank>, it shall be an
756 error.
757 This command shall be equivalent to the ex tag command, with the argu‐
759 ment to that command defined as follows.
760 If the current character is a <blank>:
762 1. Skip all <blank>s after the cursor up to the end of the line.
764 2. If the end of the line is reached, it shall be an error.
766 Then, the argument to the ex tag command shall be the current character
768 and all subsequent characters, up to the first non-word character or
769 the end of the line.
770 Move Cursor Forward
772 Synopsis:
773 [count] <space>
776 [count] l (ell)
779 If there are less than count non- <newline>s after the cursor on the
782 current line, count shall be adjusted to the number of non- <newline>s
783 after the cursor on the line.
784 If used as a motion command:
786 1. If the current or countth character after the cursor is the last
788 non- <newline> in the line, the text region shall be comprised of
789 the current character up to and including the last non- <newline>
790 in the line. Otherwise, the text region shall be from the current
791 character up to, but not including, the countth character after the
792 cursor.
793 2. Any text copied to a buffer shall be in character mode.
795 If not used as a motion command:
797 If there are no non- <newline>s after the current character on the cur‐
799 rent line, it shall be an error.
800 Current line: Unchanged.
802 Current column: Set to the last column that displays any portion of the
804 countth character after the current character.
805 Replace Text with Results from Shell Command
807 Synopsis:
808 [count] ! motion shell-commands <newline>
811 If the motion command is the ! command repeated:
814 1. If the edit buffer is empty and no count was supplied, the command
816 shall be the equivalent of the ex :read ! command, with the text
817 input, and no text shall be copied to any buffer.
818 2. Otherwise:
820 a. If there are less than count -1 lines after the current line in
822 the edit buffer, it shall be an error.
823 b. The text region shall be from the current line up to and
825 including the next count -1 lines.
826 Otherwise, the text region shall be the lines in which any character of
828 the text region specified by the motion command appear.
829 Any text copied to a buffer shall be in line mode.
831 This command shall be equivalent to the ex ! command for the specified
833 lines.
834 Move Cursor to End-of-Line
836 Synopsis:
837 [count] $
840 It shall be an error if there are less than ( count -1) lines after the
843 current line in the edit buffer.
844 If used as a motion command:
846 1. If count is 1:
848 a. It shall be an error if the line is empty.
850 b. Otherwise, the text region shall consist of all characters from
852 the starting cursor to the last non- <newline> in the line,
853 inclusive, and any text copied to a buffer shall be in charac‐
854 ter mode.
855 2. Otherwise, if the starting cursor position is at or before the
857 first non- <blank> in the line, the text region shall consist of
858 the current and the next count -1 lines, and any text saved to a
859 buffer shall be in line mode.
860 3. Otherwise, the text region shall consist of all characters from the
862 starting cursor to the last non- <newline> in the line that is
863 count -1 lines forward from the current line, and any text copied
864 to a buffer shall be in character mode.
865 If not used as a motion command:
867 Current line: Set to the current line + count-1.
869 Current column: The current column is set to the last display line col‐
871 umn of the last non- <newline> in the line, or column position 1 if the
872 line is empty.
873 The current column shall be adjusted to be on the last display line
875 column of the last non- <newline> of the current line as subsequent
876 commands change the current line, until a command changes the current
877 column.
878 Move to Matching Character
880 Synopsis:
881 %
884 If the character at the current position is not a parenthesis, bracket,
887 or curly brace, search forward in the line to the first one of those
888 characters. If no such character is found, it shall be an error.
889 The matching character shall be the parenthesis, bracket, or curly
891 brace matching the parenthesis, bracket, or curly brace, respectively,
892 that was at the current position or that was found on the current line.
893 Matching shall be determined as follows, for an open parenthesis:
895 1. Set a counter to 1.
897 2. Search forwards until a parenthesis is found or the end of the edit
899 buffer is reached.
900 3. If the end of the edit buffer is reached, it shall be an error.
902 4. If an open parenthesis is found, increment the counter by 1.
904 5. If a close parenthesis is found, decrement the counter by 1.
906 6. If the counter is zero, the current character is the matching char‐
908 acter.
909 Matching for a close parenthesis shall be equivalent, except that the
911 search shall be backwards, from the starting character to the beginning
912 of the buffer, a close parenthesis shall increment the counter by 1,
913 and an open parenthesis shall decrement the counter by 1.
914 Matching for brackets and curly braces shall be equivalent, except that
916 searching shall be done for open and close brackets or open and close
917 curly braces. It is implementation-defined whether other characters are
918 searched for and matched as well.
919 If used as a motion command:
921 1. If the matching cursor was after the starting cursor in the edit
923 buffer, and the starting cursor position was at or before the first
924 non- <blank> non- <newline> in the starting line, and the matching
925 cursor position was at or after the last non- <blank> non- <new‐
926 line> in the matching line, the text region shall consist of the
927 current line to the matching line, inclusive, and any text copied
928 to a buffer shall be in line mode.
929 2. If the matching cursor was before the starting cursor in the edit
931 buffer, and the starting cursor position was at or after the last
932 non- <blank> non- <newline> in the starting line, and the matching
933 cursor position was at or before the first non- <blank> non- <new‐
934 line> in the matching line, the text region shall consist of the
935 current line to the matching line, inclusive, and any text copied
936 to a buffer shall be in line mode.
937 3. Otherwise, the text region shall consist of the starting character
939 to the matching character, inclusive, and any text copied to a buf‐
940 fer shall be in character mode.
941 If not used as a motion command:
943 Current line: Set to the line where the matching character is located.
945 Current column: Set to the last column where any portion of the match‐
947 ing character is displayed.
948 Repeat Substitution
950 Synopsis:
951 &
954 Repeat the previous substitution command. This command shall be equiva‐
957 lent to the ex & command with the current line as its addresses, and
958 without options, count, or flags.
959 Return to Previous Context at Beginning of Line
961 Synopsis:
962 ' character
965 It shall be an error if there is no line in the edit buffer marked by
968 character.
969 If used as a motion command:
971 1. If the starting cursor is after the marked cursor, then the loca‐
973 tions of the starting cursor and the marked cursor in the edit buf‐
974 fer shall be logically swapped.
975 2. The text region shall consist of the starting line up to and
977 including the marked line, and any text copied to a buffer shall be
978 in line mode.
979 If not used as a motion command:
981 Current line: Set to the line referenced by the mark.
983 Current column: Set to non- <blank>.
985 Return to Previous Context
987 Synopsis:
988 ` character
991 It shall be an error if the marked line is no longer in the edit buf‐
994 fer. If the marked line no longer contains a character in the saved
995 numbered character position, it shall be as if the marked position is
996 the first non- <blank>.
997 If used as a motion command:
999 1. It shall be an error if the marked cursor references the same char‐
1001 acter in the edit buffer as the starting cursor.
1002 2. If the starting cursor is after the marked cursor, then the loca‐
1004 tions of the starting cursor and the marked cursor in the edit buf‐
1005 fer shall be logically swapped.
1006 3. If the starting line is empty or the starting cursor is at or
1008 before the first non- <blank> non- <newline> of the starting line,
1009 and the marked cursor line is empty or the marked cursor references
1010 the first character of the marked cursor line, the text region
1011 shall consist of all lines containing characters from the starting
1012 cursor to the line before the marked cursor line, inclusive, and
1013 any text copied to a buffer shall be in line mode.
1014 4. Otherwise, if the marked cursor line is empty or the marked cursor
1016 references a character at or before the first non- <blank> non-
1017 <newline> of the marked cursor line, the region of text shall be
1018 from the starting cursor to the last non- <newline> of the line
1019 before the marked cursor line, inclusive, and any text copied to a
1020 buffer shall be in character mode.
1021 5. Otherwise, the region of text shall be from the starting cursor
1023 (inclusive), to the marked cursor (exclusive), and any text copied
1024 to a buffer shall be in character mode.
1025 If not used as a motion command:
1027 Current line: Set to the line referenced by the mark.
1029 Current column: Set to the last column in which any portion of the
1031 character referenced by the mark is displayed.
1032 Return to Previous Section
1034 Synopsis:
1035 [count] [[
1038 Move the cursor backward through the edit buffer to the first character
1041 of the previous section boundary, count times.
1042 If used as a motion command:
1044 1. If the starting cursor was at the first character of the starting
1046 line or the starting line was empty, and the first character of the
1047 boundary was the first character of the boundary line, the text
1048 region shall consist of the current line up to and including the
1049 line where the countth next boundary starts, and any text copied to
1050 a buffer shall be in line mode.
1051 2. If the boundary was the last line of the edit buffer or the last
1053 non- <newline> of the last line of the edit buffer, the text region
1054 shall consist of the last character in the edit buffer up to and
1055 including the starting character, and any text saved to a buffer
1056 shall be in character mode.
1057 3. Otherwise, the text region shall consist of the starting character
1059 up to but not including the first character in the countth next
1060 boundary, and any text copied to a buffer shall be in character
1061 mode.
1062 If not used as a motion command:
1064 Current line: Set to the line where the countth next boundary in the
1066 edit buffer starts.
1067 Current column: Set to the last column in which any portion of the
1069 first character of the countth next boundary is displayed, or column
1070 position 1 if the line is empty.
1071 Move to Next Section
1073 Synopsis:
1074 [count] ]]
1077 Move the cursor forward through the edit buffer to the first character
1080 of the next section boundary, count times.
1081 If used as a motion command:
1083 1. If the starting cursor was at the first character of the starting
1085 line or the starting line was empty, and the first character of the
1086 boundary was the first character of the boundary line, the text
1087 region shall consist of the current line up to and including the
1088 line where the countth previous boundary starts, and any text
1089 copied to a buffer shall be in line mode.
1090 2. If the boundary was the first line of the edit buffer, the text
1092 region shall consist of the first character in the edit buffer up
1093 to but not including the starting character, and any text copied to
1094 a buffer shall be in character mode.
1095 3. Otherwise, the text region shall consist of the first character in
1097 the countth previous section boundary up to but not including the
1098 starting character, and any text copied to a buffer shall be in
1099 character mode.
1100 If not used as a motion command:
1102 Current line: Set to the line where the countth previous boundary in
1104 the edit buffer starts.
1105 Current column: Set to the last column in which any portion of the
1107 first character of the countth previous boundary is displayed, or col‐
1108 umn position 1 if the line is empty.
1109 Move to First Non-<blank> Position on Current Line
1111 Synopsis:
1112 ^
1115 If used as a motion command:
1117 1. If the line has no non- <blank> non- <newline>s, or if the cursor
1119 is at the first non- <blank> non- <newline> of the line, it shall
1120 be an error.
1121 2. If the cursor is before the first non- <blank> non- <newline> of
1123 the line, the text region shall be comprised of the current charac‐
1124 ter, up to, but not including, the first non- <blank> non- <new‐
1125 line> of the line.
1126 3. If the cursor is after the first non- <blank> non- <newline> of the
1128 line, the text region shall be from the character before the start‐
1129 ing cursor up to and including the first non- <blank> non- <new‐
1130 line> of the line.
1131 4. Any text copied to a buffer shall be in character mode.
1133 If not used as a motion command:
1135 Current line: Unchanged.
1137 Current column: Set to non- <blank>.
1139 Current and Line Above
1141 Synopsis:
1142 [count] _
1145 If there are less than count -1 lines after the current line in the
1148 edit buffer, it shall be an error.
1149 If used as a motion command:
1151 1. If count is less than 2, the text region shall be the current line.
1153 2. Otherwise, the text region shall include the starting line and the
1155 next count -1 lines.
1156 3. Any text copied to a buffer shall be in line mode.
1158 If not used as a motion command:
1160 Current line: Set to current line + count -1.
1162 Current column: Set to non- <blank>.
1164 Move Back to Beginning of Sentence
1166 Synopsis:
1167 [count] (
1170 Move backward to the beginning of a sentence. This command shall be
1173 equivalent to the [[ command, with the exception that sentence bound‐
1174 aries shall be used instead of section boundaries.
1175 Move Forward to Beginning of Sentence
1177 Synopsis:
1178 [count] )
1181 Move forward to the beginning of a sentence. This command shall be
1184 equivalent to the ]] command, with the exception that sentence bound‐
1185 aries shall be used instead of section boundaries.
1186 Move Back to Preceding Paragraph
1188 Synopsis:
1189 [count] {
1192 Move back to the beginning of the preceding paragraph. This command
1195 shall be equivalent to the [[ command, with the exception that para‐
1196 graph boundaries shall be used instead of section boundaries.
1197 Move Forward to Next Paragraph
1199 Synopsis:
1200 [count] }
1203 Move forward to the beginning of the next paragraph. This command shall
1206 be equivalent to the ]] command, with the exception that paragraph
1207 boundaries shall be used instead of section boundaries.
1208 Move to Specific Column Position
1210 Synopsis:
1211 [count] |
1214 For the purposes of this command, lines that are too long for the cur‐
1217 rent display and that have been folded shall be treated as having a
1218 single, 1-based, number of columns.
1219 If there are less than count columns in which characters from the cur‐
1221 rent line are displayed on the screen, count shall be adjusted to be
1222 the last column in which any portion of the line is displayed on the
1223 screen.
1224 If used as a motion command:
1226 1. If the line is empty, or the cursor character is the same as the
1228 character on the countth column of the line, it shall be an error.
1229 2. If the cursor is before the countth column of the line, the text
1231 region shall be comprised of the current character, up to but not
1232 including the character on the countth column of the line.
1233 3. If the cursor is after the countth column of the line, the text
1235 region shall be from the character before the starting cursor up to
1236 and including the character on the countth column of the line.
1237 4. Any text copied to a buffer shall be in character mode.
1239 If not used as a motion command:
1241 Current line: Unchanged.
1243 Current column: Set to the last column in which any portion of the
1245 character that is displayed in the count column of the line is dis‐
1246 played.
1247 Reverse Find Character
1249 Synopsis:
1250 [count] ,
1253 If the last F, f, T, or t command was F, f, T, or t, this command shall
1256 be equivalent to an f, F, t, or T command, respectively, with the spec‐
1257 ified count and the same search character.
1258 If there was no previous F, f, T, or t command, it shall be an error.
1260 Repeat
1262 Synopsis:
1263 [count] .
1266 Repeat the last !, <, >, A, C, D, I, J, O, P, R, S, X, Y, a, c, d, i,
1269 o, p, r, s, x, y, or ~ command. It shall be an error if none of these
1270 commands have been executed. Commands (other than commands that enter
1271 text input mode) executed as a result of map expansions, shall not
1272 change the value of the last repeatable command.
1273 Repeated commands with associated motion commands shall repeat the
1275 motion command as well; however, any specified count shall replace the
1276 count(s) that were originally specified to the repeated command or its
1277 associated motion command.
1278 If the motion component of the repeated command is f, F, t, or T, the
1280 repeated command shall not set the remembered search character for the
1281 ; and , commands.
1282 If the repeated command is p or P, and the buffer associated with that
1284 command was a numeric buffer named with a number less than 9, the buf‐
1285 fer associated with the repeated command shall be set to be the buffer
1286 named by the name of the previous buffer logically incremented by 1.
1287 If the repeated character is a text input command, the input text asso‐
1289 ciated with that command is repeated literally:
1290 * Input characters are neither macro or abbreviation-expanded.
1292 * Input characters are not interpreted in any special way with the
1294 exception that <newline>, <carriage-return>, and <control>-T behave
1295 as described in Input Mode Commands in vi .
1296 Current line: Set as described for the repeated command.
1298 Current column: Set as described for the repeated command.
1300 Find Regular Expression
1302 Synopsis:
1303 /
1306 If the input line contains no non- <newline>s, it shall be equivalent
1309 to a line containing only the last regular expression encountered. The
1310 enhanced regular expressions supported by vi are described in Regular
1311 Expressions in ex .
1312 Otherwise, the line shall be interpreted as one or more regular expres‐
1314 sions, optionally followed by an address offset or a vi z command.
1315 If the regular expression is not the last regular expression on the
1317 line, or if a line offset or z command is specified, the regular
1318 expression shall be terminated by an unescaped '/' character, which
1319 shall not be used as part of the regular expression. If the regular
1320 expression is not the first regular expression on the line, it shall be
1321 preceded by zero or more <blank>s, a semicolon, zero or more <blank>s,
1322 and a leading '/' character, which shall not be interpreted as part of
1323 the regular expression. It shall be an error to precede any regular
1324 expression with any characters other than these.
1325 Each search shall begin from the character after the first character of
1327 the last match (or, if it is the first search, after the cursor). If
1328 the wrapscan edit option is set, the search shall continue to the char‐
1329 acter before the starting cursor character; otherwise, to the end of
1330 the edit buffer. It shall be an error if any search fails to find a
1331 match, and an informational message to this effect shall be displayed.
1332 An optional address offset (see Addressing in ex ) can be specified
1334 after the last regular expression by including a trailing '/' character
1335 after the regular expression and specifying the address offset. This
1336 offset will be from the line containing the match for the last regular
1337 expression specified. It shall be an error if the line offset would
1338 indicate a line address less than 1 or greater than the last line in
1339 the edit buffer. An address offset of zero shall be supported. It shall
1340 be an error to follow the address offset with any other characters than
1341 <blank>s.
1342 If not used as a motion command, an optional z command (see Redraw Win‐
1344 dow ) can be specified after the last regular expression by including a
1345 trailing '/' character after the regular expression, zero or more
1346 <blank>s, a 'z' , zero or more <blank>s, an optional new window edit
1347 option value, zero or more <blank>s, and a location character. The
1348 effect shall be as if the z command was executed after the / command.
1349 It shall be an error to follow the z command with any other characters
1350 than <blank>s.
1351 The remembered search direction shall be set to forward.
1353 If used as a motion command:
1355 1. It shall be an error if the last match references the same charac‐
1357 ter in the edit buffer as the starting cursor.
1358 2. If any address offset is specified, the last match shall be
1360 adjusted by the specified offset as described previously.
1361 3. If the starting cursor is after the last match, then the locations
1363 of the starting cursor and the last match in the edit buffer shall
1364 be logically swapped.
1365 4. If any address offset is specified, the text region shall consist
1367 of all lines containing characters from the starting cursor to the
1368 last match line, inclusive, and any text copied to a buffer shall
1369 be in line mode.
1370 5. Otherwise, if the starting line is empty or the starting cursor is
1372 at or before the first non- <blank> non- <newline> of the starting
1373 line, and the last match line is empty or the last match starts at
1374 the first character of the last match line, the text region shall
1375 consist of all lines containing characters from the starting cursor
1376 to the line before the last match line, inclusive, and any text
1377 copied to a buffer shall be in line mode.
1378 6. Otherwise, if the last match line is empty or the last match begins
1380 at a character at or before the first non- <blank> non- <newline>
1381 of the last match line, the region of text shall be from the cur‐
1382 rent cursor to the last non- <newline> of the line before the last
1383 match line, inclusive, and any text copied to a buffer shall be in
1384 character mode.
1385 7. Otherwise, the region of text shall be from the current cursor
1387 (inclusive), to the first character of the last match (exclusive),
1388 and any text copied to a buffer shall be in character mode.
1389 If not used as a motion command:
1391 Current line: If a match is found, set to the last matched line plus
1393 the address offset, if any; otherwise, unchanged.
1394 Current column: Set to the last column on which any portion of the
1396 first character in the last matched string is displayed, if a match is
1397 found; otherwise, unchanged.
1398 Move to First Character in Line
1400 Synopsis:
1401 0 (zero)
1404 Move to the first character on the current line. The character '0'
1407 shall not be interpreted as a command if it is immediately preceded by
1408 a digit.
1409 If used as a motion command:
1411 1. If the cursor character is the first character in the line, it
1413 shall be an error.
1414 2. The text region shall be from the character before the cursor char‐
1416 acter up to and including the first character in the line.
1417 3. Any text copied to a buffer shall be in character mode.
1419 If not used as a motion command:
1421 Current line: Unchanged.
1423 Current column: The last column in which any portion of the first char‐
1425 acter in the line is displayed, or if the line is empty, unchanged.
1426 Execute an ex Command
1428 Synopsis:
1429 :
1432 Execute one or more ex commands.
1435 If any portion of the screen other than the last line of the screen was
1437 overwritten by any ex command (except shell), vi shall display a mes‐
1438 sage indicating that it is waiting for an input from the user, and
1439 shall then read a character. This action may also be taken for other,
1440 unspecified reasons.
1441 If the next character entered is a ':' , another ex command shall be
1443 accepted and executed. Any other character shall cause the screen to be
1444 refreshed and vi shall return to command mode.
1445 Current line: As specified for the ex command.
1447 Current column: As specified for the ex command.
1449 Repeat Find
1451 Synopsis:
1452 [count] ;
1455 This command shall be equivalent to the last F, f, T, or t command,
1458 with the specified count, and with the same search character used for
1459 the last F, f, T, or t command. If there was no previous F, f, T, or t
1460 command, it shall be an error.
1461 Shift Left
1463 Synopsis:
1464 [count] < motion
1467 If the motion command is the < command repeated:
1470 1. If there are less than count -1 lines after the current line in the
1472 edit buffer, it shall be an error.
1473 2. The text region shall be from the current line, up to and including
1475 the next count -1 lines.
1476 Shift any line in the text region specified by the count and motion
1478 command one shiftwidth (see the ex shiftwidth option) toward the start
1479 of the line, as described by the ex < command. The unshifted lines
1480 shall be copied to the unnamed buffer in line mode.
1481 Current line: If the motion was from the current cursor position toward
1483 the end of the edit buffer, unchanged. Otherwise, set to the first line
1484 in the edit buffer that is part of the text region specified by the
1485 motion command.
1486 Current column: Set to non- <blank>.
1488 Shift Right
1490 Synopsis:
1491 [count] > motion
1494 If the motion command is the > command repeated:
1497 1. If there are less than count -1 lines after the current line in the
1499 edit buffer, it shall be an error.
1500 2. The text region shall be from the current line, up to and including
1502 the next count -1 lines.
1503 Shift any line with characters in the text region specified by the
1505 count and motion command one shiftwidth (see the ex shiftwidth option)
1506 away from the start of the line, as described by the ex > command. The
1507 unshifted lines shall be copied into the unnamed buffer in line mode.
1508 Current line: If the motion was from the current cursor position toward
1510 the end of the edit buffer, unchanged. Otherwise, set to the first line
1511 in the edit buffer that is part of the text region specified by the
1512 motion command.
1513 Current column: Set to non- <blank>.
1515 Scan Backwards for Regular Expression
1517 Synopsis:
1518 ?
1521 Scan backwards; the ? command shall be equivalent to the / command (see
1524 Find Regular Expression ) with the following exceptions:
1525 1. The input prompt shall be a '?' .
1527 2. Each search shall begin from the character before the first charac‐
1529 ter of the last match (or, if it is the first search, the character
1530 before the cursor character).
1531 3. The search direction shall be from the cursor toward the beginning
1533 of the edit buffer, and the wrapscan edit option shall affect
1534 whether the search wraps to the end of the edit buffer and contin‐
1535 ues.
1536 4. The remembered search direction shall be set to backward.
1538 Execute
1540 Synopsis:
1541 @buffer
1544 If the buffer is specified as @, the last buffer executed shall be
1547 used. If no previous buffer has been executed, it shall be an error.
1548 Behave as if the contents of the named buffer were entered as standard
1550 input. After each line of a line-mode buffer, and all but the last line
1551 of a character mode buffer, behave as if a <newline> were entered as
1552 standard input.
1553 If an error occurs during this process, an error message shall be writ‐
1555 ten, and no more characters resulting from the execution of this com‐
1556 mand shall be processed.
1557 If a count is specified, behave as if that count were entered as user
1559 input before the characters from the @ buffer were entered.
1560 Current line: As specified for the individual commands.
1562 Current column: As specified for the individual commands.
1564 Reverse Case
1566 Synopsis:
1567 [count] ~
1570 Reverse the case of the current character and the next count -1 charac‐
1573 ters, such that lowercase characters that have uppercase counterparts
1574 shall be changed to uppercase characters, and uppercase characters that
1575 have lowercase counterparts shall be changed to lowercase characters,
1576 as prescribed by the current locale. No other characters shall be
1577 affected by this command.
1578 If there are less than count -1 characters after the cursor in the edit
1580 buffer, count shall be adjusted to the number of characters after the
1581 cursor in the edit buffer minus 1.
1582 For the purposes of this command, the next character after the last
1584 non- <newline> on the line shall be the next character in the edit buf‐
1585 fer.
1586 Current line: Set to the line including the ( count-1)th character
1588 after the cursor.
1589 Current column: Set to the last column in which any portion of the (
1591 count-1)th character after the cursor is displayed.
1592 Append
1594 Synopsis:
1595 [count] a
1598 Enter text input mode after the current cursor position. No characters
1601 already in the edit buffer shall be affected by this command. A count
1602 shall cause the input text to be appended count -1 more times to the
1603 end of the input.
1604 Current line/column: As specified for the text input commands (see
1606 Input Mode Commands in vi ).
1607 Append at End-of-Line
1609 Synopsis:
1610 [count] A
1613 This command shall be equivalent to the vi command:
1616 $ [ count ] a
1619 (see Append ).
1621 Move Backward to Preceding Word
1623 Synopsis:
1624 [count] b
1627 With the exception that words are used as the delimiter instead of big‐
1630 words, this command shall be equivalent to the B command.
1631 Move Backward to Preceding Bigword
1633 Synopsis:
1634 [count] B
1637 If the edit buffer is empty or the cursor is on the first character of
1640 the edit buffer, it shall be an error. If less than count bigwords
1641 begin between the cursor and the start of the edit buffer, count shall
1642 be adjusted to the number of bigword beginnings between the cursor and
1643 the start of the edit buffer.
1644 If used as a motion command:
1646 1. The text region shall be from the first character of the countth
1648 previous bigword beginning up to but not including the cursor char‐
1649 acter.
1650 2. Any text copied to a buffer shall be in character mode.
1652 If not used as a motion command:
1654 Current line: Set to the line containing the current column.
1656 Current column: Set to the last column upon which any part of the first
1658 character of the countth previous bigword is displayed.
1659 Change
1661 Synopsis:
1662 [buffer][count] c motion
1665 If the motion command is the c command repeated:
1668 1. The buffer text shall be in line mode.
1670 2. If there are less than count -1 lines after the current line in the
1672 edit buffer, it shall be an error.
1673 3. The text region shall be from the current line up to and including
1675 the next count -1 lines.
1676 Otherwise, the buffer text mode and text region shall be as specified
1678 by the motion command.
1679 The replaced text shall be copied into buffer, if specified, and into
1681 the unnamed buffer. If the text to be replaced contains characters from
1682 more than a single line, or the buffer text is in line mode, the
1683 replaced text shall be copied into the numeric buffers as well.
1684 If the buffer text is in line mode:
1686 1. Any lines that contain characters in the region shall be deleted,
1688 and the editor shall enter text input mode at the beginning of a
1689 new line which shall replace the first line deleted.
1690 2. If the autoindent edit option is set, autoindent characters equal
1692 to the autoindent characters on the first line deleted shall be
1693 inserted as if entered by the user.
1694 Otherwise, if characters from more than one line are in the region of
1696 text:
1697 1. The text shall be deleted.
1699 2. Any text remaining in the last line in the text region shall be
1701 appended to the first line in the region, and the last line in the
1702 region shall be deleted.
1703 3. The editor shall enter text input mode after the last character not
1705 deleted from the first line in the text region, if any; otherwise,
1706 on the first column of the first line in the region.
1707 Otherwise:
1709 1. If the glyph for '$' is smaller than the region, the end of the
1711 region shall be marked with a '$' .
1712 2. The editor shall enter text input mode, overwriting the region of
1714 text.
1715 Current line/column: As specified for the text input commands (see
1717 Input Mode Commands in vi ).
1718 Change to End-of-Line
1720 Synopsis:
1721 [buffer][count] C
1724 This command shall be equivalent to the vi command:
1727 [buffer][count] c$
1730 See the c command.
1732 Delete
1734 Synopsis:
1735 [buffer][count] d motion
1738 If the motion command is the d command repeated:
1741 1. The buffer text shall be in line mode.
1743 2. If there are less than count -1 lines after the current line in the
1745 edit buffer, it shall be an error.
1746 3. The text region shall be from the current line up to and including
1748 the next count -1 lines.
1749 Otherwise, the buffer text mode and text region shall be as specified
1751 by the motion command.
1752 If in open mode, and the current line is deleted, and the line remains
1754 on the display, an '@' character shall be displayed as the first glyph
1755 of that line.
1756 Delete the region of text into buffer, if specified, and into the
1758 unnamed buffer. If the text to be deleted contains characters from more
1759 than a single line, or the buffer text is in line mode, the deleted
1760 text shall be copied into the numeric buffers, as well.
1761 Current line: Set to the first text region line that appears in the
1763 edit buffer, unless that line has been deleted, in which case it shall
1764 be set to the last line in the edit buffer, or line 1 if the edit buf‐
1765 fer is empty.
1766 Current column:
1768 1. If the line is empty, set to column position 1.
1770 2. Otherwise, if the buffer text is in line mode or the motion was
1772 from the cursor toward the end of the edit buffer:
1773 a. If a character from the current line is displayed in the cur‐
1775 rent column, set to the last column that displays any portion
1776 of that character.
1777 b. Otherwise, set to the last column in which any portion of any
1779 character in the line is displayed.
1780 3. Otherwise, if a character is displayed in the column that began the
1782 text region, set to the last column that displays any portion of
1783 that character.
1784 4. Otherwise, set to the last column in which any portion of any char‐
1786 acter in the line is displayed.
1787 Delete to End-of-Line
1789 Synopsis:
1790 [buffer] D
1793 Delete the text from the current position to the end of the current
1796 line; equivalent to the vi command:
1797 [buffer] d$
1800 Move to End-of-Word
1802 Synopsis:
1803 [count] e
1806 With the exception that words are used instead of bigwords as the
1809 delimiter, this command shall be equivalent to the E command.
1810 Move to End-of-Bigword
1812 Synopsis:
1813 [count] E
1816 If the edit buffer is empty it shall be an error. If less than count
1819 bigwords end between the cursor and the end of the edit buffer, count
1820 shall be adjusted to the number of bigword endings between the cursor
1821 and the end of the edit buffer.
1822 If used as a motion command:
1824 1. The text region shall be from the last character of the countth
1826 next bigword up to and including the cursor character.
1827 2. Any text copied to a buffer shall be in character mode.
1829 If not used as a motion command:
1831 Current line: Set to the line containing the current column.
1833 Current column: Set to the last column upon which any part of the last
1835 character of the countth next bigword is displayed.
1836 Find Character in Current Line (Forward)
1838 Synopsis:
1839 [count] f character
1842 It shall be an error if count occurrences of the character do not occur
1845 after the cursor in the line.
1846 If used as a motion command:
1848 1. The text range shall be from the cursor character up to and includ‐
1850 ing the countth occurrence of the specified character after the
1851 cursor.
1852 2. Any text copied to a buffer shall be in character mode.
1854 If not used as a motion command:
1856 Current line: Unchanged.
1858 Current column: Set to the last column in which any portion of the
1860 countth occurrence of the specified character after the cursor appears
1861 in the line.
1862 Find Character in Current Line (Reverse)
1864 Synopsis:
1865 [count] F character
1868 It shall be an error if count occurrences of the character do not occur
1871 before the cursor in the line.
1872 If used as a motion command:
1874 1. The text region shall be from the countth occurrence of the speci‐
1876 fied character before the cursor, up to, but not including the cur‐
1877 sor character.
1878 2. Any text copied to a buffer shall be in character mode.
1880 If not used as a motion command:
1882 Current line: Unchanged.
1884 Current column: Set to the last column in which any portion of the
1886 countth occurrence of the specified character before the cursor appears
1887 in the line.
1888 Move to Line
1890 Synopsis:
1891 [count] G
1894 If count is not specified, it shall default to the last line of the
1897 edit buffer. If count is greater than the last line of the edit buffer,
1898 it shall be an error.
1899 If used as a motion command:
1901 1. The text region shall be from the cursor line up to and including
1903 the specified line.
1904 2. Any text copied to a buffer shall be in line mode.
1906 If not used as a motion command:
1908 Current line: Set to count if count is specified; otherwise, the last
1910 line.
1911 Current column: Set to non- <blank>.
1913 Move to Top of Screen
1915 Synopsis:
1916 [count] H
1919 If the beginning of the line count greater than the first line of which
1922 any portion appears on the display does not exist, it shall be an
1923 error.
1924 If used as a motion command:
1926 1. If in open mode, the text region shall be the current line.
1928 2. Otherwise, the text region shall be from the starting line up to
1930 and including (the first line of the display + count -1).
1931 3. Any text copied to a buffer shall be in line mode.
1933 If not used as a motion command:
1935 If in open mode, this command shall set the current column to non-
1937 <blank> and do nothing else.
1938 Otherwise, it shall set the current line and current column as follows.
1940 Current line: Set to (the first line of the display + count -1).
1942 Current column: Set to non- <blank>.
1944 Insert Before Cursor
1946 Synopsis:
1947 [count] i
1950 Enter text input mode before the current cursor position. No characters
1953 already in the edit buffer shall be affected by this command. A count
1954 shall cause the input text to be appended count -1 more times to the
1955 end of the input.
1956 Current line/column: As specified for the text input commands (see
1958 Input Mode Commands in vi ).
1959 Insert at Beginning of Line
1961 Synopsis:
1962 [count] I
1965 This command shall be equivalent to the vi command ^[ count] i.
1968 Join
1970 Synopsis:
1971 [count] J
1974 If the current line is the last line in the edit buffer, it shall be an
1977 error.
1978 This command shall be equivalent to the ex join command with no
1980 addresses, and an ex command count value of 1 if count was not speci‐
1981 fied or if a count of 1 was specified, and an ex command count value of
1982 count -1 for any other value of count, except that the current line and
1983 column shall be set as follows.
1984 Current line: Unchanged.
1986 Current column: The last column in which any portion of the character
1988 following the last character in the initial line is displayed, or the
1989 last non- <newline> in the line if no characters were appended.
1990 Move to Bottom of Screen
1992 Synopsis:
1993 [count] L
1996 If the beginning of the line count less than the last line of which any
1999 portion appears on the display does not exist, it shall be an error.
2000 If used as a motion command:
2002 1. If in open mode, the text region shall be the current line.
2004 2. Otherwise, the text region shall include all lines from the start‐
2006 ing cursor line to (the last line of the display -( count -1)).
2007 3. Any text copied to a buffer shall be in line mode.
2009 If not used as a motion command:
2011 1. If in open mode, this command shall set the current column to non-
2013 <blank> and do nothing else.
2014 2. Otherwise, it shall set the current line and current column as fol‐
2016 lows.
2017 Current line: Set to (the last line of the display -( count -1)).
2019 Current column: Set to non- <blank>.
2021 Mark Position
2023 Synopsis:
2024 m letter
2027 This command shall be equivalent to the ex mark command with the speci‐
2030 fied character as an argument.
2031 Move to Middle of Screen
2033 Synopsis:
2034 M
2037 The middle line of the display shall be calculated as follows:
2040 (the top line of the display) + (((number of lines displayed) +1) /2) -1
2043 If used as a motion command:
2045 1. If in open mode, the text region shall be the current line.
2047 2. Otherwise, the text region shall include all lines from the start‐
2049 ing cursor line up to and including the middle line of the display.
2050 3. Any text copied to a buffer shall be in line mode.
2052 If not used as a motion command:
2054 If in open mode, this command shall set the current column to non-
2056 <blank> and do nothing else.
2057 Otherwise, it shall set the current line and current column as follows.
2059 Current line: Set to the middle line of the display.
2061 Current column: Set to non- <blank>.
2063 Repeat Regular Expression Find (Forward)
2065 Synopsis:
2066 n
2069 If the remembered search direction was forward, the n command shall be
2072 equivalent to the vi / command with no characters entered by the user.
2073 Otherwise, it shall be equivalent to the vi ? command with no charac‐
2074 ters entered by the user.
2075 If the n command is used as a motion command for the ! command, the
2077 editor shall not enter text input mode on the last line on the screen,
2078 and shall behave as if the user entered a single '!' character as the
2079 text input.
2080 Repeat Regular Expression Find (Reverse)
2082 Synopsis:
2083 N
2086 Scan for the next match of the last pattern given to / or ?, but in the
2089 reverse direction; this is the reverse of n.
2090 If the remembered search direction was forward, the N command shall be
2092 equivalent to the vi ? command with no characters entered by the user.
2093 Otherwise, it shall be equivalent to the vi / command with no charac‐
2094 ters entered by the user. If the N command is used as a motion command
2095 for the ! command, the editor shall not enter text input mode on the
2096 last line on the screen, and shall behave as if the user entered a sin‐
2097 gle ! character as the text input.
2098 Insert Empty Line Below
2100 Synopsis:
2101 o
2104 Enter text input mode in a new line appended after the current line. A
2107 count shall cause the input text to be appended count -1 more times to
2108 the end of the already added text, each time starting on a new,
2109 appended line.
2110 Current line/column: As specified for the text input commands (see
2112 Input Mode Commands in vi ).
2113 Insert Empty Line Above
2115 Synopsis:
2116 O
2119 Enter text input mode in a new line inserted before the current line.
2122 A count shall cause the input text to be appended count -1 more times
2123 to the end of the already added text, each time starting on a new,
2124 appended line.
2125 Current line/column: As specified for the text input commands (see
2127 Input Mode Commands in vi ).
2128 Put from Buffer Following
2130 Synopsis:
2131 [buffer] p
2134 If no buffer is specified, the unnamed buffer shall be used.
2137 If the buffer text is in line mode, the text shall be appended below
2139 the current line, and each line of the buffer shall become a new line
2140 in the edit buffer. A count shall cause the buffer text to be appended
2141 count -1 more times to the end of the already added text, each time
2142 starting on a new, appended line.
2143 If the buffer text is in character mode, the text shall be appended
2145 into the current line after the cursor, and each line of the buffer
2146 other than the first and last shall become a new line in the edit buf‐
2147 fer. A count shall cause the buffer text to be appended count -1 more
2148 times to the end of the already added text, each time starting after
2149 the last added character.
2150 Current line: If the buffer text is in line mode, set the line to line
2152 +1; otherwise, unchanged.
2153 Current column: If the buffer text is in line mode:
2155 1. If there is a non- <blank> in the first line of the buffer, set to
2157 the last column on which any portion of the first non- <blank> in
2158 the line is displayed.
2159 2. If there is no non- <blank> in the first line of the buffer, set to
2161 the last column on which any portion of the last non- <newline> in
2162 the first line of the buffer is displayed.
2163 If the buffer text is in character mode:
2165 1. If the text in the buffer is from more than a single line, then set
2167 to the last column on which any portion of the first character from
2168 the buffer is displayed.
2169 2. Otherwise, if the buffer is the unnamed buffer, set to the last
2171 column on which any portion of the last character from the buffer
2172 is displayed.
2173 3. Otherwise, set to the first column on which any portion of the
2175 first character from the buffer is displayed.
2176 Put from Buffer Before
2178 Synopsis:
2179 [buffer] P
2182 If no buffer is specified, the unnamed buffer shall be used.
2185 If the buffer text is in line mode, the text shall be inserted above
2187 the current line, and each line of the buffer shall become a new line
2188 in the edit buffer. A count shall cause the buffer text to be appended
2189 count -1 more times to the end of the already added text, each time
2190 starting on a new, appended line.
2191 If the buffer text is in character mode, the text shall be inserted
2193 into the current line before the cursor, and each line of the buffer
2194 other than the first and last shall become a new line in the edit buf‐
2195 fer. A count shall cause the buffer text to be appended count -1 more
2196 times to the end of the already added text, each time starting after
2197 the last added character.
2198 Current line: Unchanged.
2200 Current column: If the buffer text is in line mode:
2202 1. If there is a non- <blank> in the first line of the buffer, set to
2204 the last column on which any portion of that character is dis‐
2205 played.
2206 2. If there is no non- <blank> in the first line of the buffer, set to
2208 the last column on which any portion of the last non- <newline> in
2209 the first line of the buffer is displayed.
2210 If the buffer text is in character mode:
2212 1. If the buffer is the unnamed buffer, set to the last column on
2214 which any portion of the last character from the buffer is dis‐
2215 played.
2216 2. Otherwise, set to the first column on which any portion of the
2218 first character from the buffer is displayed.
2219 Enter ex Mode
2221 Synopsis:
2222 Q
2225 Leave visual or open mode and enter ex command mode.
2228 Current line: Unchanged.
2230 Current column: Unchanged.
2232 Replace Character
2234 Synopsis:
2235 [count] r character
2238 Replace the count characters at and after the cursor with the specified
2241 character. If there are less than count non- <newline>s at and after
2242 the cursor on the line, it shall be an error.
2243 If character is <control>-V, any next character other than the <new‐
2245 line> shall be stripped of any special meaning and used as a literal
2246 character.
2247 If character is <ESC>, no replacement shall be made and the current
2249 line and current column shall be unchanged.
2250 If character is <carriage-return> or <newline>, count new lines shall
2252 be appended to the current line. All but the last of these lines shall
2253 be empty. count characters at and after the cursor shall be discarded,
2254 and any remaining characters after the cursor in the current line shall
2255 be moved to the last of the new lines. If the autoindent edit option is
2256 set, they shall be preceded by the same number of autoindent characters
2257 found on the line from which the command was executed.
2258 Current line: Unchanged unless the replacement character is a <car‐
2260 riage-return> or <newline>, in which case it shall be set to line +
2261 count.
2262 Current column: Set to the last column position on which a portion of
2264 the last replaced character is displayed, or if the replacement charac‐
2265 ter caused new lines to be created, set to non- <blank>.
2266 Replace Characters
2268 Synopsis:
2269 R
2272 Enter text input mode at the current cursor position possibly replacing
2275 text on the current line. A count shall cause the input text to be
2276 appended count -1 more times to the end of the input.
2277 Current line/column: As specified for the text input commands (see
2279 Input Mode Commands in vi ).
2280 Substitute Character
2282 Synopsis:
2283 [buffer][count] s
2286 This command shall be equivalent to the vi command:
2289 [buffer][count] c<space>
2292 Substitute Lines
2294 Synopsis:
2295 [buffer][count] S
2298 This command shall be equivalent to the vi command:
2301 [buffer][count] c_
2304 Move Cursor to Before Character (Forward)
2306 Synopsis:
2307 [count] t character
2310 It shall be an error if count occurrences of the character do not occur
2313 after the cursor in the line.
2314 If used as a motion command:
2316 1. The text region shall be from the cursor up to but not including
2318 the countth occurrence of the specified character after the cursor.
2319 2. Any text copied to a buffer shall be in character mode.
2321 If not used as a motion command:
2323 Current line: Unchanged.
2325 Current column: Set to the last column in which any portion of the
2327 character before the countth occurrence of the specified character
2328 after the cursor appears in the line.
2329 Move Cursor to After Character (Reverse)
2331 Synopsis:
2332 [count] T character
2335 It shall be an error if count occurrences of the character do not occur
2338 before the cursor in the line.
2339 If used as a motion command:
2341 1. If the character before the cursor is the specified character, it
2343 shall be an error.
2344 2. The text region shall be from the character before the cursor up to
2346 but not including the countth occurrence of the specified character
2347 before the cursor.
2348 3. Any text copied to a buffer shall be in character mode.
2350 If not used as a motion command:
2352 Current line: Unchanged.
2354 Current column: Set to the last column in which any portion of the
2356 character after the countth occurrence of the specified character
2357 before the cursor appears in the line.
2358 Undo
2360 Synopsis:
2361 u
2364 This command shall be equivalent to the ex undo command except that the
2367 current line and current column shall be set as follows:
2368 Current line: Set to the first line added or changed if any; otherwise,
2370 move to the line preceding any deleted text if one exists; otherwise,
2371 move to line 1.
2372 Current column: If undoing an ex command, set to the first non-
2374 <blank>.
2375 Otherwise, if undoing a text input command:
2377 1. If the command was a C, c, O, o, R, S, or s command, the current
2379 column shall be set to the value it held when the text input com‐
2380 mand was entered.
2381 2. Otherwise, set to the last column in which any portion of the first
2383 character after the deleted text is displayed, or, if no non- <new‐
2384 line>s follow the text deleted from this line, set to the last col‐
2385 umn in which any portion of the last non- <newline> in the line is
2386 displayed, or 1 if the line is empty.
2387 Otherwise, if a single line was modified (that is, not added or
2389 deleted) by the u command:
2390 1. If text was added or changed, set to the last column in which any
2392 portion of the first character added or changed is displayed.
2393 2. If text was deleted, set to the last column in which any portion of
2395 the first character after the deleted text is displayed, or, if no
2396 non- <newline>s follow the deleted text, set to the last column in
2397 which any portion of the last non- <newline> in the line is dis‐
2398 played, or 1 if the line is empty.
2399 Otherwise, set to non- <blank>.
2401 Undo Current Line
2403 Synopsis:
2404 U
2407 Restore the current line to its state immediately before the most
2410 recent time that it became the current line.
2411 Current line: Unchanged.
2413 Current column: Set to the first column in the line in which any por‐
2415 tion of the first character in the line is displayed.
2416 Move to Beginning of Word
2418 Synopsis:
2419 [count] w
2422 With the exception that words are used as the delimiter instead of big‐
2425 words, this command shall be equivalent to the W command.
2426 Move to Beginning of Bigword
2428 Synopsis:
2429 [count] W
2432 If the edit buffer is empty, it shall be an error. If there are less
2435 than count bigwords between the cursor and the end of the edit buffer,
2436 count shall be adjusted to move the cursor to the last bigword in the
2437 edit buffer.
2438 If used as a motion command:
2440 1. If the associated command is c, count is 1, and the cursor is on a
2442 <blank>, the region of text shall be the current character and no
2443 further action shall be taken.
2444 2. If there are less than count bigwords between the cursor and the
2446 end of the edit buffer, then the command shall succeed, and the
2447 region of text shall include the last character of the edit buffer.
2448 3. If there are <blank>s or an end-of-line that precede the countth
2450 bigword, and the associated command is c, the region of text shall
2451 be up to and including the last character before the preceding
2452 <blank>s or end-of-line.
2453 4. If there are <blank>s or an end-of-line that precede the bigword,
2455 and the associated command is d or y, the region of text shall be
2456 up to and including the last <blank> before the start of the big‐
2457 word or end-of-line.
2458 5. Any text copied to a buffer shall be in character mode.
2460 If not used as a motion command:
2462 1. If the cursor is on the last character of the edit buffer, it shall
2464 be an error.
2465 Current line: Set to the line containing the current column.
2467 Current column: Set to the last column in which any part of the first
2469 character of the countth next bigword is displayed.
2470 Delete Character at Cursor
2472 Synopsis:
2473 [buffer][count] x
2476 Delete the count characters at and after the current character into
2479 buffer, if specified, and into the unnamed buffer.
2480 If the line is empty, it shall be an error. If there are less than
2482 count non- <newline>s at and after the cursor on the current line,
2483 count shall be adjusted to the number of non- <newline>s at and after
2484 the cursor.
2485 Current line: Unchanged.
2487 Current column: If the line is empty, set to column position 1. Other‐
2489 wise, if there were count or less non- <newline>s at and after the cur‐
2490 sor on the current line, set to the last column that displays any part
2491 of the last non- <newline> of the line. Otherwise, unchanged.
2492 Delete Character Before Cursor
2494 Synopsis:
2495 [buffer][count] X
2498 Delete the count characters before the current character into buffer,
2501 if specified, and into the unnamed buffer.
2502 If there are no characters before the current character on the current
2504 line, it shall be an error. If there are less than count previous char‐
2505 acters on the current line, count shall be adjusted to the number of
2506 previous characters on the line.
2507 Current line: Unchanged.
2509 Current column: Set to (current column - the width of the deleted char‐
2511 acters).
2512 Yank
2514 Synopsis:
2515 [buffer][count] y motion
2518 Copy (yank) the region of text into buffer, if specified, and into the
2521 unnamed buffer.
2522 If the motion command is the y command repeated:
2524 1. The buffer shall be in line mode.
2526 2. If there are less than count -1 lines after the current line in the
2528 edit buffer, it shall be an error.
2529 3. The text region shall be from the current line up to and including
2531 the next count -1 lines.
2532 Otherwise, the buffer text mode and text region shall be as specified
2534 by the motion command.
2535 Current line: If the motion was from the current cursor position toward
2537 the end of the edit buffer, unchanged. Otherwise, set to the first line
2538 in the edit buffer that is part of the text region specified by the
2539 motion command.
2540 Current column:
2542 1. If the motion was from the current cursor position toward the end
2544 of the edit buffer, unchanged.
2545 2. Otherwise, if the current line is empty, set to column position 1.
2547 3. Otherwise, set to the last column that displays any part of the
2549 first character in the file that is part of the text region speci‐
2550 fied by the motion command.
2551 Yank Current Line
2553 Synopsis:
2554 [buffer][count] Y
2557 This command shall be equivalent to the vi command:
2560 [buffer][count] y_
2563 Redraw Window
2565 If in open mode, the z command shall have the Synopsis:
2566 Synopsis:
2568 [count] z
2571 If count is not specified, it shall default to the window edit option
2574 -1. The z command shall be equivalent to the ex z command, with a type
2575 character of = and a count of count -2, except that the current line
2576 and current column shall be set as follows, and the window edit option
2577 shall not be affected. If the calculation for the count argument would
2578 result in a negative number, the count argument to the ex z command
2579 shall be zero. A blank line shall be written after the last line is
2580 written.
2581 Current line: Unchanged.
2583 Current column: Unchanged.
2585 If not in open mode, the z command shall have the following Synopsis:
2587 Synopsis:
2589 [line] z [count] character
2592 If line is not specified, it shall default to the current line. If
2595 line is specified, but is greater than the number of lines in the edit
2596 buffer, it shall default to the number of lines in the edit buffer.
2597 If count is specified, the value of the window edit option shall be set
2599 to count (as described in the ex window command), and the screen shall
2600 be redrawn.
2601 line shall be placed as specified by the following characters:
2603 <newline>, <carriage-return>
2605 Place the beginning of the line on the first line of the dis‐
2607 play.
2608 . Place the beginning of the line in the center of the display.
2610 The middle line of the display shall be calculated as described
2611 for the M command.
2612 - Place an unspecified portion of the line on the last line of the
2614 display.
2615 + If line was specified, equivalent to the <newline> case. If line
2617 was not specified, display a screen where the first line of the
2618 display shall be (current last line) +1. If there are no lines
2619 after the last line in the display, it shall be an error.
2620 ^ If line was specified, display a screen where the last line of
2622 the display shall contain an unspecified portion of the first
2623 line of a display that had an unspecified portion of the speci‐
2624 fied line on the last line of the display. If this calculation
2625 results in a line before the beginning of the edit buffer, dis‐
2626 play the first screen of the edit buffer.
2627 Otherwise, display a screen where the last line of the display shall
2629 contain an unspecified portion of (current first line -1). If this
2630 calculation results in a line before the beginning of the edit buffer,
2631 it shall be an error.
2632 Current line: If line and the '^' character were specified:
2635 1. If the first screen was displayed as a result of the command
2637 attempting to display lines before the beginning of the edit buf‐
2638 fer: if the first screen was already displayed, unchanged; other‐
2639 wise, set to (current first line -1).
2640 2. Otherwise, set to the last line of the display.
2642 If line and the '+' character were specified, set to the first line of
2644 the display.
2645 Otherwise, if line was specified, set to line.
2647 Otherwise, unchanged.
2649 Current column: Set to non- <blank>.
2651 Exit
2653 Synopsis:
2654 ZZ
2657 This command shall be equivalent to the ex xit command with no
2660 addresses, trailing !, or filename (see the ex xit command).
2661 Input Mode Commands in vi
2663 In text input mode, the current line shall consist of zero or more of
2664 the following categories, plus the terminating <newline>:
2665 1. Characters preceding the text input entry point
2667 Characters in this category shall not be modified during text input
2669 mode.
2670 2. autoindent characters
2672 autoindent characters shall be automatically inserted into each line
2674 that is created in text input mode, either as a result of entering a
2675 <newline> or <carriage-return> while in text input mode, or as an
2676 effect of the command itself; for example, O or o (see the ex autoin‐
2677 dent command), as if entered by the user.
2678 It shall be possible to erase autoindent characters with the <con‐
2680 trol>-D command; it is unspecified whether they can be erased by <con‐
2681 trol>-H, <control>-U, and <control>-W characters. Erasing any autoin‐
2682 dent character turns the glyph into erase-columns and deletes the char‐
2683 acter from the edit buffer, but does not change its representation on
2684 the screen.
2685 3. Text input characters
2687 Text input characters are the characters entered by the user. Erasing
2689 any text input character turns the glyph into erase-columns and deletes
2690 the character from the edit buffer, but does not change its representa‐
2691 tion on the screen.
2692 Each text input character entered by the user (that does not have a
2694 special meaning) shall be treated as follows:
2695 a. The text input character shall be appended to the last char‐
2697 acter in the edit buffer from the first, second, or third
2698 categories.
2699 b. If there are no erase-columns on the screen, the text input
2701 command was the R command, and characters in the fifth cate‐
2702 gory from the original line follow the cursor, the next such
2703 character shall be deleted from the edit buffer. If the
2704 slowopen edit option is not set, the corresponding glyph on
2705 the screen shall become erase-columns.
2706 c. If there are erase-columns on the screen, as many columns as
2708 they occupy, or as are necessary, shall be overwritten to
2709 display the text input character. (If only part of a multi-
2710 column glyph is overwritten, the remainder shall be left on
2711 the screen, and continue to be treated as erase-columns; it
2712 is unspecified whether the remainder of the glyph is modi‐
2713 fied in any way.)
2714 d. If additional display line columns are needed to display the
2716 text input character:
2717 1. If the slowopen edit option is set, the text input char‐
2719 acters shall be displayed on subsequent display line
2720 columns, overwriting any characters displayed in those
2721 columns.
2722 2. Otherwise, any characters currently displayed on or
2724 after the column on the display line where the text
2725 input character is to be displayed shall be pushed ahead
2726 the number of display line columns necessary to display
2727 the rest of the text input character.
2728 4. Erase-columns
2730 Erase-columns are not logically part of the edit buffer, appearing only
2732 on the screen, and may be overwritten on the screen by subsequent text
2733 input characters. When text input mode ends, all erase-columns shall no
2734 longer appear on the screen.
2735 Erase-columns are initially the region of text specified by the c com‐
2737 mand (see Change ); however, erasing autoindent or text input charac‐
2738 ters causes the glyphs of the erased characters to be treated as erase-
2739 columns.
2740 5. Characters following the text region for the c command, or the text
2742 input entry point for all other commands
2743 Characters in this category shall not be modified during text input
2745 mode, except as specified in category 3.b. for the R text input com‐
2746 mand, or as <blank>s deleted when a <newline> or <carriage-return> is
2747 entered.
2748 It is unspecified whether it is an error to attempt to erase past the
2750 beginning of a line that was created by the entry of a <newline> or
2751 <carriage-return> during text input mode. If it is not an error, the
2752 editor shall behave as if the erasing character was entered immediately
2753 after the last text input character entered on the previous line, and
2754 all of the non- <newline>s on the current line shall be treated as
2755 erase-columns.
2756 When text input mode is entered, or after a text input mode character
2758 is entered (except as specified for the special characters below), the
2759 cursor shall be positioned as follows:
2760 1. On the first column that displays any part of the first erase-col‐
2762 umn, if one exists
2763 2. Otherwise, if the slowopen edit option is set, on the first display
2765 line column after the last character in the first, second, or third
2766 categories, if one exists
2767 3. Otherwise, the first column that displays any part of the first
2769 character in the fifth category, if one exists
2770 4. Otherwise, the display line column after the last character in the
2772 first, second, or third categories, if one exists
2773 5. Otherwise, on column position 1
2775 The characters that are updated on the screen during text input mode
2777 are unspecified, other than that the last text input character shall
2778 always be updated, and, if the slowopen edit option is not set, the
2779 current cursor character shall always be updated.
2780 The following specifications are for command characters entered during
2782 text input mode.
2783 NUL
2785 Synopsis:
2786 NUL
2789 If the first character of the text input is a NUL, the most recently
2792 input text shall be input as if entered by the user, and then text
2793 input mode shall be exited. The text shall be input literally; that is,
2794 characters are neither macro or abbreviation expanded, nor are any
2795 characters interpreted in any special manner. It is unspecified
2796 whether implementations shall support more than 256 bytes of remembered
2797 input text.
2798 <control>-D
2800 Synopsis:
2801 <control>-D
2804 The <control>-D character shall have no special meaning when in text
2807 input mode for a line-oriented command (see Command Descriptions in vi
2808 ).
2809 This command need not be supported on block-mode terminals.
2811 If the cursor does not follow an autoindent character, or an autoindent
2813 character and a '0' or '^' character:
2814 1. If the cursor is in column position 1, the <control>-D character
2816 shall be discarded and no further action taken.
2817 2. Otherwise, the <control>-D character shall have no special meaning.
2819 If the last input character was a '0' , the cursor shall be moved to
2821 column position 1.
2822 Otherwise, if the last input character was a '^' , the cursor shall be
2824 moved to column position 1. In addition, the autoindent level for the
2825 next input line shall be derived from the same line from which the
2826 autoindent level for the current input line was derived.
2827 Otherwise, the cursor shall be moved back to the column after the pre‐
2829 vious shiftwidth (see the ex shiftwidth command) boundary.
2830 All of the glyphs on columns between the starting cursor position and
2832 (inclusively) the ending cursor position shall become erase-columns as
2833 described in Input Mode Commands in vi .
2834 Current line: Unchanged.
2836 Current column: Set to 1 if the <control>-D was preceded by a '^' or
2838 '0' ; otherwise, set to (column -1) -((column -2) % shiftwidth).
2839 <control>-H
2841 Synopsis:
2842 <control>-H
2845 If in text input mode for a line-oriented command, and there are no
2848 characters to erase, text input mode shall be terminated, no further
2849 action shall be done for this command, and the current line and column
2850 shall be unchanged.
2851 If there are characters other than autoindent characters that have been
2853 input on the current line before the cursor, the cursor shall move back
2854 one character.
2855 Otherwise, if there are autoindent characters on the current line
2857 before the cursor, it is implementation-defined whether the <control>-H
2858 command is an error or if the cursor moves back one autoindent charac‐
2859 ter.
2860 Otherwise, if the cursor is in column position 1 and there are previous
2862 lines that have been input, it is implementation-defined whether the
2863 <control>-H command is an error or if it is equivalent to entering
2864 <control>-H after the last input character on the previous input line.
2865 Otherwise, it shall be an error.
2867 All of the glyphs on columns between the starting cursor position and
2869 (inclusively) the ending cursor position shall become erase-columns as
2870 described in Input Mode Commands in vi .
2871 The current erase character (see stty) shall cause an equivalent action
2873 to the <control>-H command, unless the previously inserted character
2874 was a backslash, in which case it shall be as if the literal current
2875 erase character had been inserted instead of the backslash.
2876 Current line: Unchanged, unless previously input lines are erased, in
2878 which case it shall be set to line -1.
2879 Current column: Set to the first column that displays any portion of
2881 the character backed up over.
2882 <newline>
2884 Synopsis:
2885 <newline>
2888 <carriage-return>
2891 <control>-J
2894 <control>-M
2897 If input was part of a line-oriented command, text input mode shall be
2900 terminated and the command shall continue execution with the input pro‐
2901 vided.
2902 Otherwise, terminate the current line. If there are no characters other
2904 than autoindent characters on the line, all characters on the line
2905 shall be discarded. Otherwise, it is unspecified whether the autoindent
2906 characters in the line are modified by entering these characters.
2907 Continue text input mode on a new line appended after the current line.
2909 If the slowopen edit option is set, the lines on the screen below the
2910 current line shall not be pushed down, but the first of them shall be
2911 cleared and shall appear to be overwritten. Otherwise, the lines of the
2912 screen below the current line shall be pushed down.
2913 If the autoindent edit option is set, an appropriate number of autoin‐
2915 dent characters shall be added as a prefix to the line as described by
2916 the ex autoindent edit option.
2917 All columns after the cursor that are erase-columns (as described in
2919 Input Mode Commands in vi ) shall be discarded.
2920 If the autoindent edit option is set, all <blank>s immediately follow‐
2922 ing the cursor shall be discarded.
2923 All remaining characters after the cursor shall be transferred to the
2925 new line, positioned after any autoindent characters.
2926 Current line: Set to current line +1.
2928 Current column: Set to the first column that displays any portion of
2930 the first character after the autoindent characters on the new line, if
2931 any, or the first column position after the last autoindent character,
2932 if any, or column position 1.
2933 <control>-T
2935 Synopsis:
2936 <control>-T
2939 The <control>-T character shall have no special meaning when in text
2942 input mode for a line-oriented command (see Command Descriptions in vi
2943 ).
2944 This command need not be supported on block-mode terminals.
2946 Behave as if the user entered the minimum number of <blank>s necessary
2948 to move the cursor forward to the column position after the next
2949 shiftwidth (see the ex shiftwidth command) boundary.
2950 Current line: Unchanged.
2952 Current column: Set to column + shiftwidth - ((column -1) %
2954 shiftwidth).
2955 <control>-U
2957 Synopsis:
2958 <control>-U
2961 If there are characters other than autoindent characters that have been
2964 input on the current line before the cursor, the cursor shall move to
2965 the first character input after the autoindent characters.
2966 Otherwise, if there are autoindent characters on the current line
2968 before the cursor, it is implementation-defined whether the <control>-U
2969 command is an error or if the cursor moves to the first column position
2970 on the line.
2971 Otherwise, if the cursor is in column position 1 and there are previous
2973 lines that have been input, it is implementation-defined whether the
2974 <control>-U command is an error or if it is equivalent to entering
2975 <control>-U after the last input character on the previous input line.
2976 Otherwise, it shall be an error.
2978 All of the glyphs on columns between the starting cursor position and
2980 (inclusively) the ending cursor position shall become erase-columns as
2981 described in Input Mode Commands in vi .
2982 The current kill character (see stty) shall cause an equivalent action
2984 to the <control>-U command, unless the previously inserted character
2985 was a backslash, in which case it shall be as if the literal current
2986 kill character had been inserted instead of the backslash.
2987 Current line: Unchanged, unless previously input lines are erased, in
2989 which case it shall be set to line -1.
2990 Current column: Set to the first column that displays any portion of
2992 the last character backed up over.
2993 <control>-V
2995 Synopsis:
2996 <control>-V
2999 <control>-Q
3002 Allow the entry of any subsequent character, other than <control>-J or
3005 the <newline>, as a literal character, removing any special meaning
3006 that it may have to the editor in text input mode. If a <control>-V or
3007 <control>-Q is entered before a <control>-J or <newline>, the <con‐
3008 trol>-V or <control>-Q character shall be discarded, and the <con‐
3009 trol>-J or <newline> shall behave as described in the <newline> command
3010 character during input mode.
3011 For purposes of the display only, the editor shall behave as if a '^'
3013 character was entered, and the cursor shall be positioned as if over‐
3014 writing the '^' character. When a subsequent character is entered, the
3015 editor shall behave as if that character was entered instead of the
3016 original <control>-V or <control>-Q character.
3017 Current line: Unchanged.
3019 Current column: Unchanged.
3021 <control>-W
3023 Synopsis:
3024 <control>-W
3027 If there are characters other than autoindent characters that have been
3030 input on the current line before the cursor, the cursor shall move back
3031 over the last word preceding the cursor (including any <blank>s between
3032 the end of the last word and the current cursor); the cursor shall not
3033 move to before the first character after the end of any autoindent
3034 characters.
3035 Otherwise, if there are autoindent characters on the current line
3037 before the cursor, it is implementation-defined whether the <control>-W
3038 command is an error or if the cursor moves to the first column position
3039 on the line.
3040 Otherwise, if the cursor is in column position 1 and there are previous
3042 lines that have been input, it is implementation-defined whether the
3043 <control>-W command is an error or if it is equivalent to entering
3044 <control>-W after the last input character on the previous input line.
3045 Otherwise, it shall be an error.
3047 All of the glyphs on columns between the starting cursor position and
3049 (inclusively) the ending cursor position shall become erase-columns as
3050 described in Input Mode Commands in vi .
3051 Current line: Unchanged, unless previously input lines are erased, in
3053 which case it shall be set to line -1.
3054 Current column: Set to the first column that displays any portion of
3056 the last character backed up over.
3057 <ESC>
3059 Synopsis:
3060 <ESC>
3063 If input was part of a line-oriented command:
3066 1. If interrupt was entered, text input mode shall be terminated and
3068 the editor shall return to command mode. The terminal shall be
3069 alerted.
3070 2. If <ESC> was entered, text input mode shall be terminated and the
3072 command shall continue execution with the input provided.
3073 Otherwise, terminate text input mode and return to command mode.
3075 Any autoindent characters entered on newly created lines that have no
3077 other non- <newline>s shall be deleted.
3078 Any leading autoindent and <blank>s on newly created lines shall be
3080 rewritten to be the minimum number of <blank>s possible.
3081 The screen shall be redisplayed as necessary to match the contents of
3083 the edit buffer.
3084 Current line: Unchanged.
3086 Current column:
3088 1. If there are text input characters on the current line, the column
3090 shall be set to the last column where any portion of the last text
3091 input character is displayed.
3092 2. Otherwise, if a character is displayed in the current column,
3094 unchanged.
3095 3. Otherwise, set to column position 1.
3097
3099 The following exit values shall be returned:
3100 0 Successful completion.
3102 >0 An error occurred.
3104
3107 When any error is encountered and the standard input is not a terminal
3108 device file, vi shall not write the file or return to command or text
3109 input mode, and shall terminate with a non-zero exit status.
3110 Otherwise, when an unrecoverable error is encountered it shall be
3112 equivalent to a SIGHUP asynchronous event.
3113 Otherwise, when an error is encountered, the editor shall behave as
3115 specified in Command Descriptions in vi .
3116 The following sections are informative.
3118
3120 None.
3121
3123 None.
3124
3126 See the RATIONALE for ex for more information on vi. Major portions of
3127 the vi utility specification point to ex to avoid inadvertent diver‐
3128 gence. While ex and vi have historically been implemented as a single
3129 utility, this is not required by IEEE Std 1003.1-2001.
3130 It is recognized that portions of vi would be difficult, if not impos‐
3132 sible, to implement satisfactorily on a block-mode terminal, or a ter‐
3133 minal without any form of cursor addressing, thus it is not a mandatory
3134 requirement that such features should work on all terminals. It is the
3135 intention, however, that a vi implementation should provide the full
3136 set of capabilities on all terminals capable of supporting them.
3137 Historically, vi exited immediately if the standard input was not a
3139 terminal. IEEE Std 1003.1-2001 permits, but does not require, this
3140 behavior. An end-of-file condition is not equivalent to an end-of-file
3141 character. A common end-of-file character, <control>-D, is historically
3142 a vi command.
3143 The text in the STDOUT section reflects the usage of the verb display
3145 in this section; some implementations of vi use standard output to
3146 write to the terminal, but IEEE Std 1003.1-2001 does not require that
3147 to be the case.
3148 Historically, implementations reverted to open mode if the terminal was
3150 incapable of supporting full visual mode. IEEE Std 1003.1-2001
3151 requires this behavior. Historically, the open mode of vi behaved
3152 roughly equivalently to the visual mode, with the exception that only a
3153 single line from the edit buffer (one "buffer line") was kept current
3154 at any time. This line was normally displayed on the next-to-last line
3155 of a terminal with cursor addressing (and the last line performed its
3156 normal visual functions for line-oriented commands and messages). In
3157 addition, some few commands behaved differently in open mode than in
3158 visual mode. IEEE Std 1003.1-2001 requires conformance to historical
3159 practice.
3160 Historically, ex and vi implementations have expected text to proceed
3162 in the usual European/Latin order of left to right, top to bottom.
3163 There is no requirement in IEEE Std 1003.1-2001 that this be the case.
3164 The specification was deliberately written using words like "before",
3165 "after", "first", and "last" in order to permit implementations to sup‐
3166 port the natural text order of the language.
3167 Historically, lines past the end of the edit buffer were marked with
3169 single tilde ( '~' ) characters; that is, if the one-based display was
3170 20 lines in length, and the last line of the file was on line one, then
3171 lines 2-20 would contain only a single '~' character.
3172 Historically, the vi editor attempted to display only complete lines at
3174 the bottom of the screen (it did display partial lines at the top of
3175 the screen). If a line was too long to fit in its entirety at the bot‐
3176 tom of the screen, the screen lines where the line would have been dis‐
3177 played were displayed as single '@' characters, instead of displaying
3178 part of the line. IEEE Std 1003.1-2001 permits, but does not require,
3179 this behavior. Implementations are encouraged to attempt always to
3180 display a complete line at the bottom of the screen when doing
3181 scrolling or screen positioning by buffer lines.
3182 Historically, lines marked with '@' were also used to minimize output
3184 to dumb terminals over slow lines; that is, changes local to the cursor
3185 were updated, but changes to lines on the screen that were not close to
3186 the cursor were simply marked with an '@' sign instead of being updated
3187 to match the current text. IEEE Std 1003.1-2001 permits, but does not
3188 require this feature because it is used ever less frequently as termi‐
3189 nals become smarter and connections are faster.
3190 Initialization in ex and vi
3192 Historically, vi always had a line in the edit buffer, even if the edit
3193 buffer was "empty". For example:
3194 1. The ex command = executed from visual mode wrote "1" when the buf‐
3196 fer was empty.
3197 2. Writes from visual mode of an empty edit buffer wrote files of a
3199 single character (a <newline>), while writes from ex mode of an
3200 empty edit buffer wrote empty files.
3201 3. Put and read commands into an empty edit buffer left an empty line
3203 at the top of the edit buffer.
3204 For consistency, IEEE Std 1003.1-2001 does not permit any of these
3206 behaviors.
3207 Historically, vi did not always return the terminal to its original
3209 modes; for example, ICRNL was modified if it was not originally set.
3210 IEEE Std 1003.1-2001 does not permit this behavior.
3211 Command Descriptions in vi
3213 Motion commands are among the most complicated aspects of vi to
3214 describe. With some exceptions, the text region and buffer type effect
3215 of a motion command on a vi command are described on a case-by-case
3216 basis. The descriptions of text regions in IEEE Std 1003.1-2001 are not
3217 intended to imply direction; that is, an inclusive region from line n
3218 to line n+5 is identical to a region from line n+5 to line n. This is
3219 of more than academic interest-movements to marks can be in either
3220 direction, and, if the wrapscan option is set, so can movements to
3221 search points. Historically, lines are always stored into buffers in
3222 text order; that is, from the start of the edit buffer to the end.
3223 IEEE Std 1003.1-2001 requires conformance to historical practice.
3224 Historically, command counts were applied to any associated motion, and
3226 were multiplicative to any supplied motion count. For example, 2cw is
3227 the same as c2w, and 2c3w is the same as c6w. IEEE Std 1003.1-2001
3228 requires this behavior. Historically, vi commands that used bigwords,
3229 words, paragraphs, and sentences as objects treated groups of empty
3230 lines, or lines that contained only <blank>s, inconsistently. Some
3231 commands treated them as a single entity, while others treated each
3232 line separately. For example, the w, W, and B commands treated groups
3233 of empty lines as individual words; that is, the command would move the
3234 cursor to each new empty line. The e and E commands treated groups of
3235 empty lines as a single word; that is, the first use would move past
3236 the group of lines. The b command would just beep at the user, or if
3237 done from the start of the line as a motion command, fail in unexpected
3238 ways. If the lines contained only (or ended with) <blank>s, the w and W
3239 commands would just beep at the user, the E and e commands would treat
3240 the group as a single word, and the B and b commands would treat the
3241 lines as individual words. For consistency and simplicity of specifica‐
3242 tion, IEEE Std 1003.1-2001 requires that all vi commands treat groups
3243 of empty or blank lines as a single entity, and that movement through
3244 lines ending with <blank>s be consistent with other movements.
3245 Historically, vi documentation indicated that any number of double
3247 quotes were skipped after punctuation marks at sentence boundaries;
3248 however, implementations only skipped single quotes.
3249 IEEE Std 1003.1-2001 requires both to be skipped.
3250 Historically, the first and last characters in the edit buffer were
3252 word boundaries. This historical practice is required by
3253 IEEE Std 1003.1-2001.
3254 Historically, vi attempted to update the minimum number of columns on
3256 the screen possible, which could lead to misleading information being
3257 displayed. IEEE Std 1003.1-2001 makes no requirements other than that
3258 the current character being entered is displayed correctly, leaving all
3259 other decisions in this area up to the implementation.
3260 Historically, lines were arbitrarily folded between columns of any
3262 characters that required multiple column positions on the screen, with
3263 the exception of tabs, which terminated at the right-hand margin.
3264 IEEE Std 1003.1-2001 permits the former and requires the latter. Imple‐
3265 mentations that do not arbitrarily break lines between columns of char‐
3266 acters that occupy multiple column positions should not permit the cur‐
3267 sor to rest on a column that does not contain any part of a character.
3268 The historical vi had a problem in that all movements were by buffer
3270 lines, not by display or screen lines. This is often the right thing to
3271 do; for example, single line movements, such as j or k, should work on
3272 buffer lines. Commands like dj, or j., where . is a change command,
3273 only make sense for buffer lines. It is not, however, the right thing
3274 to do for screen motion or scrolling commands like <control>-D, <con‐
3275 trol>-F, and H. If the window is fairly small, using buffer lines in
3276 these cases can result in completely random motion; for example, 1
3277 <control>-D can result in a completely changed screen, without any
3278 overlap. This is clearly not what the user wanted. The problem is even
3279 worse in the case of the H, L, and M commands-as they position the cur‐
3280 sor at the first non- <blank> of the line, they may all refer to the
3281 same location in large lines, and will result in no movement at all.
3282 In addition, if the line is larger than the screen, using buffer lines
3284 can make it impossible to display parts of the line-there are not any
3285 commands that do not display the beginning of the line in historical
3286 vi, and if both the beginning and end of the line cannot be on the
3287 screen at the same time, the user suffers. Finally, the page and half-
3288 page scrolling commands historically moved to the first non- <blank> in
3289 the new line. If the line is approximately the same size as the screen,
3290 this is inadequate because the cursor before and after a <control>-D
3291 command will refer to the same location on the screen.
3292 Implementations of ex and vi exist that do not have these problems
3294 because the relevant commands ( <control>-B, <control>-D, <control>-F,
3295 <control>-U, <control>-Y, <control>-E, H, L, and M) operate on display
3296 (screen) lines, not (edit) buffer lines.
3297 IEEE Std 1003.1-2001 does not permit this behavior by default because
3299 the standard developers believed that users would find it too confus‐
3300 ing. However, historical practice has been relaxed. For example, ex and
3301 vi historically attempted, albeit sometimes unsuccessfully, to never
3302 put part of a line on the last lines of a screen; for example, if a
3303 line would not fit in its entirety, no part of the line was displayed,
3304 and the screen lines corresponding to the line contained single '@'
3305 characters. This behavior is permitted, but not required by
3306 IEEE Std 1003.1-2001, so that it is possible for implementations to
3307 support long lines in small screens more reasonably without changing
3308 the commands to be oriented to the display (instead of oriented to the
3309 buffer). IEEE Std 1003.1-2001 also permits implementations to refuse
3310 to edit any edit buffer containing a line that will not fit on the
3311 screen in its entirety.
3312 The display area (for example, the value of the window edit option) has
3314 historically been "grown", or expanded, to display new text when local
3315 movements are done in displays where the number of lines displayed is
3316 less than the maximum possible. Expansion has historically been the
3317 first choice, when the target line is less than the maximum possible
3318 expansion value away. Scrolling has historically been the next choice,
3319 done when the target line is less than half a display away, and other‐
3320 wise, the screen was redrawn. There were exceptions, however, in that
3321 ex commands generally always caused the screen to be redrawn.
3322 IEEE Std 1003.1-2001 does not specify a standard behavior because there
3323 may be external issues, such as connection speed, the number of charac‐
3324 ters necessary to redraw as opposed to scroll, or terminal capabilities
3325 that implementations will have to accommodate.
3326 The current line in IEEE Std 1003.1-2001 maps one-to-one to a buffer
3328 line in the file. The current column does not. There are two different
3329 column values that are described by IEEE Std 1003.1-2001. The first is
3330 the current column value as set by many of the vi commands. This value
3331 is remembered for the lifetime of the editor. The second column value
3332 is the actual position on the screen where the cursor rests. The two
3333 are not always the same. For example, when the cursor is backed by a
3334 multi-column character, the actual cursor position on the screen has
3335 historically been the last column of the character in command mode, and
3336 the first column of the character in input mode.
3337 Commands that set the current line, but that do not set the current
3339 cursor value (for example, j and k) attempt to get as close as possible
3340 to the remembered column position, so that the cursor tends to restrict
3341 itself to a vertical column as the user moves around in the edit buf‐
3342 fer. IEEE Std 1003.1-2001 requires conformance to historical practice,
3343 requiring that the display location of the cursor on the display line
3344 be adjusted from the current column value as necessary to support this
3345 historical behavior.
3346 Historically, only a single line (and for some terminals, a single line
3348 minus 1 column) of characters could be entered by the user for the
3349 line-oriented commands; that is, :, !, /, or ?. IEEE Std 1003.1-2001
3350 permits, but does not require, this limitation.
3351 Historically, "soft" errors in vi caused the terminal to be alerted,
3353 but no error message was displayed. As a general rule, no error message
3354 was displayed for errors in command execution in vi, when the error
3355 resulted from the user attempting an invalid or impossible action, or
3356 when a searched-for object was not found. Examples of soft errors
3357 included h at the left margin, <control>-B or [[ at the beginning of
3358 the file, 2G at the end of the file, and so on. In addition, errors
3359 such as %, ]], }, ), N, n, f, F, t, and T failing to find the searched-
3360 for object were soft as well. Less consistently, / and ? displayed an
3361 error message if the pattern was not found, /, ?, N, and n displayed an
3362 error message if no previous regular expression had been specified, and
3363 ; did not display an error message if no previous f, F, t, or T command
3364 had occurred. Also, behavior in this area might reasonably be based on
3365 a runtime evaluation of the speed of a network connection. Finally,
3366 some implementations have provided error messages for soft errors in
3367 order to assist naive users, based on the value of a verbose edit
3368 option. IEEE Std 1003.1-2001 does not list specific errors for which an
3369 error message shall be displayed. Implementations should conform to
3370 historical practice in the absence of any strong reason to diverge.
3371 Page Backwards
3373 The <control>-B and <control>-F commands historically considered it an
3374 error to attempt to page past the beginning or end of the file, whereas
3375 the <control>-D and <control>-U commands simply moved to the beginning
3376 or end of the file. For consistency, IEEE Std 1003.1-2001 requires the
3377 latter behavior for all four commands. All four commands still consider
3378 it an error if the current line is at the beginning ( <control>-B,
3379 <control>-U) or end ( <control>-F, <control>-D) of the file. Histori‐
3380 cally, the <control>-B and <control>-F commands skip two lines in order
3381 to include overlapping lines when a single command is entered. This
3382 makes less sense in the presence of a count, as there will be, by defi‐
3383 nition, no overlapping lines. The actual calculation used by historical
3384 implementations of the vi editor for <control>-B was:
3385 ((current first line) - count x (window edit option)) +2
3388 and for <control>-F was:
3390 ((current first line) + count x (window edit option)) -2
3393 This calculation does not work well when intermixing commands with and
3395 without counts; for example, 3 <control>-F is not equivalent to enter‐
3396 ing the <control>-F command three times, and is not reversible by
3397 entering the <control>-B command three times. For consistency with
3398 other vi commands that take counts, IEEE Std 1003.1-2001 requires a
3399 different calculation.
3400 Scroll Forward
3402 The 4BSD and System V implementations of vi differed on the initial
3403 value used by the scroll command. 4BSD used:
3404 ((window edit option) +1) /2
3407 while System V used the value of the scroll edit option. The System V
3409 version is specified by IEEE Std 1003.1-2001 because the standard
3410 developers believed that it was more intuitive and permitted the user a
3411 method of setting the scroll value initially without also setting the
3412 number of lines that are displayed.
3413 Scroll Forward by Line
3415 Historically, the <control>-E and <control>-Y commands considered it an
3416 error if the last and first lines, respectively, were already on the
3417 screen. IEEE Std 1003.1-2001 requires conformance to historical prac‐
3418 tice. Historically, the <control>-E and <control>-Y commands had no
3419 effect in open mode. For simplicity and consistency of specification,
3420 IEEE Std 1003.1-2001 requires that they behave as usual, albeit with a
3421 single line screen.
3422 Clear and Redisplay
3424 The historical <control>-L command refreshed the screen exactly as it
3425 was supposed to be currently displayed, replacing any '@' characters
3426 for lines that had been deleted but not updated on the screen with
3427 refreshed '@' characters. The intent of the <control>-L command is to
3428 refresh when the screen has been accidentally overwritten; for example,
3429 by a write command from another user, or modem noise.
3430 Redraw Screen
3432 The historical <control>-R command redisplayed only when necessary to
3433 update lines that had been deleted but not updated on the screen and
3434 that were flagged with '@' characters. There is no requirement that the
3435 screen be in any way refreshed if no lines of this form are currently
3436 displayed. IEEE Std 1003.1-2001 permits implementations to extend this
3437 command to refresh lines on the screen flagged with '@' characters
3438 because they are too long to be displayed in the current framework;
3439 however, the current line and column need not be modified.
3440 Search for tagstring
3442 Historically, the first non- <blank> at or after the cursor was the
3443 first character, and all subsequent characters that were word charac‐
3444 ters, up to the end of the line, were included. For example, with the
3445 cursor on the leading space or on the '#' character in the text "#bar@"
3446 , the tag was "#bar" . On the character 'b' it was "bar" , and on the
3447 'a' it was "ar" . IEEE Std 1003.1-2001 requires this behavior.
3448 Replace Text with Results from Shell Command
3450 Historically, the <, >, and ! commands considered most cursor motions
3451 other than line-oriented motions an error; for example, the command
3452 >/foo<CR> succeeded, while the command >l failed, even though the text
3453 region described by the two commands might be identical. For consis‐
3454 tency, all three commands only consider entire lines and not partial
3455 lines, and the region is defined as any line that contains a character
3456 that was specified by the motion.
3457 Move to Matching Character
3459 Other matching characters have been left implementation-defined in
3460 order to allow extensions such as matching '<' and '>' for searching
3461 HTML, or #ifdef, #else, and #endif for searching C source.
3462 Repeat Substitution
3464 IEEE Std 1003.1-2001 requires that any c and g flags specified to the
3465 previous substitute command be ignored; however, the r flag may still
3466 apply, if supported by the implementation.
3467 Return to Previous (Context or Section)
3469 The [[, ]], (, ), {, and } commands are all affected by "section bound‐
3470 aries", but in some historical implementations not all of the commands
3471 recognize the same section boundaries. This is a bug, not a feature,
3472 and a unique section-boundary algorithm was not described for each com‐
3473 mand. One special case that is preserved is that the sentence command
3474 moves to the end of the last line of the edit buffer while the other
3475 commands go to the beginning, in order to preserve the traditional
3476 character cut semantics of the sentence command. Historically, vi sec‐
3477 tion boundaries at the beginning and end of the edit buffer were the
3478 first non- <blank> on the first and last lines of the edit buffer if
3479 one exists; otherwise, the last character of the first and last lines
3480 of the edit buffer if one exists. To increase consistency with other
3481 section locations, this has been simplified by IEEE Std 1003.1-2001 to
3482 the first character of the first and last lines of the edit buffer, or
3483 the first and the last lines of the edit buffer if they are empty.
3484 Sentence boundaries were problematic in the historical vi. They were
3486 not only the boundaries as defined for the section and paragraph com‐
3487 mands, but they were the first non- <blank> that occurred after those
3488 boundaries, as well. Historically, the vi section commands were docu‐
3489 mented as taking an optional window size as a count preceding the com‐
3490 mand. This was not implemented in historical versions, so
3491 IEEE Std 1003.1-2001 requires that the count repeat the command, for
3492 consistency with other vi commands.
3493 Repeat
3495 Historically, mapped commands other than text input commands could not
3496 be repeated using the period command. IEEE Std 1003.1-2001 requires
3497 conformance to historical practice.
3498 The restrictions on the interpretation of special characters (for exam‐
3500 ple, <control>-H) in the repetition of text input mode commands is
3501 intended to match historical practice. For example, given the input
3502 sequence:
3503 iab<control>-H<control>-H<control>-Hdef<escape>
3506 the user should be informed of an error when the sequence is first
3508 entered, but not during a command repetition. The character <control>-T
3509 is specifically exempted from this restriction. Historical implementa‐
3510 tions of vi ignored <control>-T characters that were input in the orig‐
3511 inal command during command repetition. IEEE Std 1003.1-2001 prohibits
3512 this behavior.
3513 Find Regular Expression
3515 Historically, commands did not affect the line searched to or from if
3516 the motion command was a search ( /, ?, N, n) and the final position
3517 was the start/end of the line. There were some special cases and vi was
3518 not consistent. IEEE Std 1003.1-2001 does not permit this behavior, for
3519 consistency. Historical implementations permitted but were unable to
3520 handle searches as motion commands that wrapped (that is, due to the
3521 edit option wrapscan) to the original location. IEEE Std 1003.1-2001
3522 requires that this behavior be treated as an error.
3523 Historically, the syntax "/RE/0" was used to force the command to cut
3525 text in line mode. IEEE Std 1003.1-2001 requires conformance to histor‐
3526 ical practice.
3527 Historically, in open mode, a z specified to a search command redis‐
3529 played the current line instead of displaying the current screen with
3530 the current line highlighted. For consistency and simplicity of speci‐
3531 fication, IEEE Std 1003.1-2001 does not permit this behavior.
3532 Historically, trailing z commands were permitted and ignored if entered
3534 as part of a search used as a motion command. For consistency and sim‐
3535 plicity of specification, IEEE Std 1003.1-2001 does not permit this
3536 behavior.
3537 Execute an ex Command
3539 Historically, vi implementations restricted the commands that could be
3540 entered on the colon command line (for example, append and change), and
3541 some other commands were known to cause them to fail catastrophically.
3542 For consistency, IEEE Std 1003.1-2001 does not permit these restric‐
3543 tions. When executing an ex command by entering :, it is not possible
3544 to enter a <newline> as part of the command because it is considered
3545 the end of the command. A different approach is to enter ex command
3546 mode by using the vi Q command (and later resuming visual mode with the
3547 ex vi command). In ex command mode, the single-line limitation does not
3548 exist. So, for example, the following is valid:
3549 Q
3552 s/break here/break\
3553 here/
3554 vi
3555 IEEE Std 1003.1-2001 requires that, if the ex command overwrites any
3557 part of the screen that would be erased by a refresh, vi pauses for a
3558 character from the user. Historically, this character could be any
3559 character; for example, a character input by the user before the mes‐
3560 sage appeared, or even a mapped character. This is probably a bug, but
3561 implementations that have tried to be more rigorous by requiring that
3562 the user enter a specific character, or that the user enter a character
3563 after the message was displayed, have been forced by user indignation
3564 back into historical behavior. IEEE Std 1003.1-2001 requires confor‐
3565 mance to historical practice.
3566 Shift Left (Right)
3568 Refer to the Rationale for the ! and / commands. Historically, the <
3569 and > commands sometimes moved the cursor to the first non- <blank>
3570 (for example if the command was repeated or with _ as the motion com‐
3571 mand), and sometimes left it unchanged. IEEE Std 1003.1-2001 does not
3572 permit this inconsistency, requiring instead that the cursor always
3573 move to the first non- <blank>. Historically, the < and > commands did
3574 not support buffer arguments, although some implementations allow the
3575 specification of an optional buffer. This behavior is neither required
3576 nor disallowed by IEEE Std 1003.1-2001.
3577 Execute
3579 Historically, buffers could execute other buffers, and loops, infinite
3580 and otherwise, were possible. IEEE Std 1003.1-2001 requires confor‐
3581 mance to historical practice. The * buffer syntax of ex is not
3582 required in vi, because it is not historical practice and has been used
3583 in some vi implementations to support additional scripting languages.
3584 Reverse Case
3586 Historically, the ~ command ignored any associated count, and acted
3587 only on the characters in the current line. For consistency with other
3588 vi commands, IEEE Std 1003.1-2001 requires that an associated count act
3589 on the next count characters, and that the command move to subsequent
3590 lines if warranted by count, to make it possible to modify large pieces
3591 of text in a reasonably efficient manner. There exist vi implementa‐
3592 tions that optionally require an associated motion command for the ~
3593 command. Implementations supporting this functionality are encouraged
3594 to base it on the tildedop edit option and handle the text regions and
3595 cursor positioning identically to the yank command.
3596 Append
3598 Historically, counts specified to the A, a, I, and i commands repeated
3599 the input of the first line count times, and did not repeat the subse‐
3600 quent lines of the input text. IEEE Std 1003.1-2001 requires that the
3601 entire text input be repeated count times.
3602 Move Backward to Preceding Word
3604 Historically, vi became confused if word commands were used as motion
3605 commands in empty files. IEEE Std 1003.1-2001 requires that this be an
3606 error. Historical implementations of vi had a large number of bugs in
3607 the word movement commands, and they varied greatly in behavior in the
3608 presence of empty lines, "words" made up of a single character, and
3609 lines containing only <blank>s. For consistency and simplicity of spec‐
3610 ification, IEEE Std 1003.1-2001 does not permit this behavior.
3611 Change to End-of-Line
3613 Some historical implementations of the C command did not behave as
3614 described by IEEE Std 1003.1-2001 when the $ key was remapped because
3615 they were implemented by pushing the $ key onto the input queue and
3616 reprocessing it. IEEE Std 1003.1-2001 does not permit this behavior.
3617 Historically, the C, S, and s commands did not copy replaced text into
3618 the numeric buffers. For consistency and simplicity of specification,
3619 IEEE Std 1003.1-2001 requires that they behave like their respective c
3620 commands in all respects.
3621 Delete
3623 Historically, lines in open mode that were deleted were scrolled up,
3624 and an @ glyph written over the beginning of the line. In the case of
3625 terminals that are incapable of the necessary cursor motions, the edi‐
3626 tor erased the deleted line from the screen. IEEE Std 1003.1-2001
3627 requires conformance to historical practice; that is, if the terminal
3628 cannot display the '@' character, the line cannot remain on the screen.
3629 Delete to End-of-Line
3631 Some historical implementations of the D command did not behave as
3632 described by IEEE Std 1003.1-2001 when the $ key was remapped because
3633 they were implemented by pushing the $ key onto the input queue and
3634 reprocessing it. IEEE Std 1003.1-2001 does not permit this behavior.
3635 Join
3637 An historical oddity of vi is that the commands J, 1J, and 2J are all
3638 equivalent. IEEE Std 1003.1-2001 requires conformance to historical
3639 practice. The vi J command is specified in terms of the ex join com‐
3640 mand with an ex command count value. The address correction for a count
3641 that is past the end of the edit buffer is necessary for historical
3642 compatibility for both ex and vi.
3643 Mark Position
3645 Historical practice is that only lowercase letters, plus '`' and '" ,
3646 could be used to mark a cursor position. IEEE Std 1003.1-2001 requires
3647 conformance to historical practice, but encourages implementations to
3648 support other characters as marks as well.
3649 Repeat Regular Expression Find (Forward and Reverse)
3651 Historically, the N and n commands could not be used as motion compo‐
3652 nents for the c command. With the exception of the cN command, which
3653 worked if the search crossed a line boundary, the text region would be
3654 discarded, and the user would not be in text input mode. For consis‐
3655 tency and simplicity of specification, IEEE Std 1003.1-2001 does not
3656 permit this behavior.
3657 Insert Empty Line (Below and Above)
3659 Historically, counts to the O and o commands were used as the number of
3660 physical lines to open, if the terminal was dumb and the slowopen
3661 option was not set. This was intended to minimize traffic over slow
3662 connections and repainting for dumb terminals. IEEE Std 1003.1-2001
3663 does not permit this behavior, requiring that a count to the open com‐
3664 mand behave as for other text input commands. This change to historical
3665 practice was made for consistency, and because a superset of the func‐
3666 tionality is provided by the slowopen edit option.
3667 Put from Buffer (Following and Before)
3669 Historically, counts to the p and P commands were ignored if the buffer
3670 was a line mode buffer, but were (mostly) implemented as described in
3671 IEEE Std 1003.1-2001 if the buffer was a character mode buffer. Because
3672 implementations exist that do not have this limitation, and because
3673 pasting lines multiple times is generally useful, IEEE Std 1003.1-2001
3674 requires that count be supported for all p and P commands.
3675 Historical implementations of vi were widely known to have major prob‐
3677 lems in the p and P commands, particularly when unusual regions of text
3678 were copied into the edit buffer. The standard developers viewed these
3679 as bugs, and they are not permitted for consistency and simplicity of
3680 specification.
3681 Historically, a P or p command (or an ex put command executed from open
3683 or visual mode) executed in an empty file, left an empty line as the
3684 first line of the file. For consistency and simplicity of specifica‐
3685 tion, IEEE Std 1003.1-2001 does not permit this behavior.
3686 Replace Character
3688 Historically, the r command did not correctly handle the erase and word
3689 erase characters as arguments, nor did it handle an associated count
3690 greater than 1 with a <carriage-return> argument, for which it replaced
3691 count characters with a single <newline>. IEEE Std 1003.1-2001 does not
3692 permit these inconsistencies.
3693 Historically, the r command permitted the <control>-V escaping of
3695 entered characters, such as <ESC> and the <carriage-return>; however,
3696 it required two leading <control>-V characters instead of one.
3697 IEEE Std 1003.1-2001 requires that this be changed for consistency with
3698 the other text input commands of vi.
3699 Historically, it is an error to enter the r command if there are less
3701 than count characters at or after the cursor in the line. While a rea‐
3702 sonable and unambiguous extension would be to permit the r command on
3703 empty lines, it would require that too large a count be adjusted to
3704 match the number of characters at or after the cursor for consistency,
3705 which is sufficiently different from historical practice to be avoided.
3706 IEEE Std 1003.1-2001 requires conformance to historical practice.
3707 Replace Characters
3709 Historically, if there were autoindent characters in the line on which
3710 the R command was run, and autoindent was set, the first <newline>
3711 would be properly indented and no characters would be replaced by the
3712 <newline>. Each additional <newline> would replace n characters, where
3713 n was the number of characters that were needed to indent the rest of
3714 the line to the proper indentation level. This behavior is a bug and is
3715 not permitted by IEEE Std 1003.1-2001.
3716 Undo
3718 Historical practice for cursor positioning after undoing commands was
3719 mixed. In most cases, when undoing commands that affected a single
3720 line, the cursor was moved to the start of added or changed text, or
3721 immediately after deleted text. However, if the user had moved from the
3722 line being changed, the column was either set to the first non-
3723 <blank>, returned to the origin of the command, or remained unchanged.
3724 When undoing commands that affected multiple lines or entire lines, the
3725 cursor was moved to the first character in the first line restored. As
3726 an example of how inconsistent this was, a search, followed by an o
3727 text input command, followed by an undo would return the cursor to the
3728 location where the o command was entered, but a cw command followed by
3729 an o command followed by an undo would return the cursor to the first
3730 non- <blank> of the line. IEEE Std 1003.1-2001 requires the most useful
3731 of these behaviors, and discards the least useful, in the interest of
3732 consistency and simplicity of specification.
3733 Yank
3735 Historically, the yank command did not move to the end of the motion if
3736 the motion was in the forward direction. It moved to the end of the
3737 motion if the motion was in the backward direction, except for the _
3738 command, or for the G and ' commands when the end of the motion was on
3739 the current line. This was further complicated by the fact that for a
3740 number of motion commands, the yank command moved the cursor but did
3741 not update the screen; for example, a subsequent command would move the
3742 cursor from the end of the motion, even though the cursor on the screen
3743 had not reflected the cursor movement for the yank command.
3744 IEEE Std 1003.1-2001 requires that all yank commands associated with
3745 backward motions move the cursor to the end of the motion for consis‐
3746 tency, and specifically, to make ' commands as motions consistent with
3747 search patterns as motions.
3748 Yank Current Line
3750 Some historical implementations of the Y command did not behave as
3751 described by IEEE Std 1003.1-2001 when the '_' key was remapped because
3752 they were implemented by pushing the '_' key onto the input queue and
3753 reprocessing it. IEEE Std 1003.1-2001 does not permit this behavior.
3754 Redraw Window
3756 Historically, the z command always redrew the screen. This is permitted
3757 but not required by IEEE Std 1003.1-2001, because of the frequent use
3758 of the z command in macros such as map n nz. for screen positioning,
3759 instead of its use to change the screen size. The standard developers
3760 believed that expanding or scrolling the screen offered a better inter‐
3761 face for users. The ability to redraw the screen is preserved if the
3762 optional new window size is specified, and in the <control>-L and <con‐
3763 trol>-R commands.
3764 The semantics of z^ are confusing at best. Historical practice is that
3766 the screen before the screen that ended with the specified line is dis‐
3767 played. IEEE Std 1003.1-2001 requires conformance to historical prac‐
3768 tice.
3769 Historically, the z command would not display a partial line at the top
3771 or bottom of the screen. If the partial line would normally have been
3772 displayed at the bottom of the screen, the command worked, but the par‐
3773 tial line was replaced with '@' characters. If the partial line would
3774 normally have been displayed at the top of the screen, the command
3775 would fail. For consistency and simplicity of specification,
3776 IEEE Std 1003.1-2001 does not permit this behavior.
3777 Historically, the z command with a line specification of 1 ignored the
3779 command. For consistency and simplicity of specification,
3780 IEEE Std 1003.1-2001 does not permit this behavior.
3781 Historically, the z command did not set the cursor column to the first
3783 non- <blank> for the character if the first screen was to be displayed,
3784 and was already displayed. For consistency and simplicity of specifica‐
3785 tion, IEEE Std 1003.1-2001 does not permit this behavior.
3786 Input Mode Commands in vi
3788 Historical implementations of vi did not permit the user to erase more
3789 than a single line of input, or to use normal erase characters such as
3790 line erase, worderase, and erase to erase autoindent characters. As
3791 there exist implementations of vi that do not have these limitations,
3792 both behaviors are permitted, but only historical practice is required.
3793 In the case of these extensions, vi is required to pause at the autoin‐
3794 dent and previous line boundaries.
3795 Historical implementations of vi updated only the portion of the screen
3797 where the current cursor character was displayed. For example, con‐
3798 sider the vi input keystrokes:
3799 iabcd<escape>0C<tab>
3802 Historically, the <tab> would overwrite the characters "abcd" when it
3804 was displayed. Other implementations replace only the 'a' character
3805 with the <tab>, and then push the rest of the characters ahead of the
3806 cursor. Both implementations have problems. The historical implementa‐
3807 tion is probably visually nicer for the above example; however, for the
3808 keystrokes:
3809 iabcd<ESC>0R<tab><ESC>
3812 the historical implementation results in the string "bcd" disappearing
3814 and then magically reappearing when the <ESC> character is entered.
3815 IEEE Std 1003.1-2001 requires the former behavior when overwriting
3816 erase-columns-that is, overwriting characters that are no longer logi‐
3817 cally part of the edit buffer-and the latter behavior otherwise.
3818 Historical implementations of vi discarded the <control>-D and <con‐
3820 trol>-T characters when they were entered at places where their command
3821 functionality was not appropriate. IEEE Std 1003.1-2001 requires that
3822 the <control>-T functionality always be available, and that <control>-D
3823 be treated as any other key when not operating on autoindent charac‐
3824 ters.
3825 NUL
3827 Some historical implementations of vi limited the number of characters
3828 entered using the NUL input character to 256 bytes.
3829 IEEE Std 1003.1-2001 permits this limitation; however, implementations
3830 are encouraged to remove this limit.
3831 <control>-D
3833 See also Rationale for the input mode command <newline>. The hidden
3834 assumptions in the <control>-D command (and in the vi autoindent speci‐
3835 fication in general) is that <space>s take up a single column on the
3836 screen and that <tab>s are comprised of an integral number of <space>s.
3837 <newline>
3839 Implementations are permitted to rewrite autoindent characters in the
3840 line when <newline>, <carriage-return>, <control>-D, and <control>-T
3841 are entered, or when the shift commands are used, because historical
3842 implementations have both done so and found it necessary to do so. For
3843 example, a <control>-D when the cursor is preceded by a single <tab>,
3844 with tabstop set to 8, and shiftwidth set to 3, will result in the
3845 <tab> being replaced by several <space>s.
3846 <control>-T
3848 See also the Rationale for the input mode command <newline>. Histori‐
3849 cally, <control>-T only worked if no non- <blank>s had yet been input
3850 in the current input line. In addition, the characters inserted by
3851 <control>-T were treated as autoindent characters, and could not be
3852 erased using normal user erase characters. Because implementations
3853 exist that do not have these limitations, and as moving to a column
3854 boundary is generally useful, IEEE Std 1003.1-2001 requires that both
3855 limitations be removed.
3856 <control>-V
3858 Historically, vi used ^V, regardless of the value of the literal-next
3859 character of the terminal. IEEE Std 1003.1-2001 requires conformance
3860 to historical practice.
3861 The uses described for <control>-V can also be accomplished with <con‐
3863 trol>-Q, which is useful on terminals that use <control>-V for the
3864 down-arrow function. However, most historical implementations use <con‐
3865 trol>-Q for the termios START character, so the editor will generally
3866 not receive the <control>-Q unless stty ixon mode is set to off. (In
3867 addition, some historical implementations of vi explicitly set ixon
3868 mode to on, so it was difficult for the user to set it to off.) Any of
3869 the command characters described in IEEE Std 1003.1-2001 can be made
3870 ineffective by their selection as termios control characters, using the
3871 stty utility or other methods described in the System Interfaces volume
3872 of IEEE Std 1003.1-2001.
3873 <ESC>
3875 Historically, SIGINT alerted the terminal when used to end input mode.
3876 This behavior is permitted, but not required, by IEEE Std 1003.1-2001.
3877
3879 None.
3880
3882 ed , ex , stty
3883
3885 Portions of this text are reprinted and reproduced in electronic form
3886 from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
3887 -- Portable Operating System Interface (POSIX), The Open Group Base
3888 Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of
3889 Electrical and Electronics Engineers, Inc and The Open Group. In the
3890 event of any discrepancy between this version and the original IEEE and
3891 The Open Group Standard, the original IEEE and The Open Group Standard
3892 is the referee document. The original Standard can be obtained online
3893 at http://www.opengroup.org/unix/online.html .
3894IEEE/The Open Group 2003 VI(P)