1ED(1P) POSIX Programmer's Manual ED(1P)
2
6 This manual page is part of the POSIX Programmer's Manual. The Linux
7 implementation of this interface may differ (consult the corresponding
8 Linux manual page for details of Linux behavior), or the interface may
9 not be implemented on Linux.
10
12 ed — edit text
13
15 ed [-p string] [-s] [file]
16
18 The ed utility is a line-oriented text editor that uses two modes: com‐
19 mand mode and input mode. In command mode the input characters shall
20 be interpreted as commands, and in input mode they shall be interpreted
21 as text. See the EXTENDED DESCRIPTION section.
22 If an operand is '-', the results are unspecified.
24
26 The ed utility shall conform to the Base Definitions volume of
27 POSIX.1‐2017, Section 12.2, Utility Syntax Guidelines, except for the
28 unspecified usage of '-'.
29 The following options shall be supported:
31 -p string Use string as the prompt string when in command mode. By
33 default, there shall be no prompt string.
34 -s Suppress the writing of byte counts by e, E, r, and w com‐
36 mands and of the '!' prompt after a !command.
37
39 The following operand shall be supported:
40 file If the file argument is given, ed shall simulate an e command
42 on the file named by the pathname, file, before accepting
43 commands from the standard input.
44
46 The standard input shall be a text file consisting of commands, as
47 described in the EXTENDED DESCRIPTION section.
48
50 The input files shall be text files.
51
53 The following environment variables shall affect the execution of ed:
54 HOME Determine the pathname of the user's home directory.
56 LANG Provide a default value for the internationalization vari‐
58 ables that are unset or null. (See the Base Definitions vol‐
59 ume of POSIX.1‐2017, Section 8.2, Internationalization Vari‐
60 ables for the precedence of internationalization variables
61 used to determine the values of locale categories.)
62 LC_ALL If set to a non-empty string value, override the values of
64 all the other internationalization variables.
65 LC_COLLATE
67 Determine the locale for the behavior of ranges, equivalence
68 classes, and multi-character collating elements within regu‐
69 lar expressions.
70 LC_CTYPE Determine the locale for the interpretation of sequences of
72 bytes of text data as characters (for example, single-byte as
73 opposed to multi-byte characters in arguments and input
74 files) and the behavior of character classes within regular
75 expressions.
76 LC_MESSAGES
78 Determine the locale that should be used to affect the format
79 and contents of diagnostic messages written to standard error
80 and informative messages written to standard output.
81 NLSPATH Determine the location of message catalogs for the processing
83 of LC_MESSAGES.
84
86 The ed utility shall take the standard action for all signals (see the
87 ASYNCHRONOUS EVENTS section in Section 1.4, Utility Description
88 Defaults) with the following exceptions:
89 SIGINT The ed utility shall interrupt its current activity, write
91 the string "?\n" to standard output, and return to command
92 mode (see the EXTENDED DESCRIPTION section).
93 SIGHUP If the buffer is not empty and has changed since the last
95 write, the ed utility shall attempt to write a copy of the
96 buffer in a file. First, the file named ed.hup in the current
97 directory shall be used; if that fails, the file named ed.hup
98 in the directory named by the HOME environment variable shall
99 be used. In any case, the ed utility shall exit without writ‐
100 ing the file to the currently remembered pathname and without
101 returning to command mode.
102 SIGQUIT The ed utility shall ignore this event.
104
106 Various editing commands and the prompting feature (see -p) write to
107 standard output, as described in the EXTENDED DESCRIPTION section.
108
110 The standard error shall be used only for diagnostic messages.
111
113 The output files shall be text files whose formats are dependent on the
114 editing commands given.
115
117 The ed utility shall operate on a copy of the file it is editing;
118 changes made to the copy shall have no effect on the file until a w
119 (write) command is given. The copy of the text is called the buffer.
120 Commands to ed have a simple and regular structure: zero, one, or two
122 addresses followed by a single-character command, possibly followed by
123 parameters to that command. These addresses specify one or more lines
124 in the buffer. Every command that requires addresses has default
125 addresses, so that the addresses very often can be omitted. If the -p
126 option is specified, the prompt string shall be written to standard
127 output before each command is read.
128 In general, only one command can appear on a line. Certain commands
130 allow text to be input. This text is placed in the appropriate place in
131 the buffer. While ed is accepting text, it is said to be in input mode.
132 In this mode, no commands shall be recognized; all input is merely col‐
133 lected. Input mode is terminated by entering a line consisting of two
134 characters: a <period> ('.') followed by a <newline>. This line is
135 not considered part of the input text.
136 Regular Expressions in ed
138 The ed utility shall support basic regular expressions, as described in
139 the Base Definitions volume of POSIX.1‐2017, Section 9.3, Basic Regular
140 Expressions. Since regular expressions in ed are always matched
141 against single lines (excluding the terminating <newline> characters),
142 never against any larger section of text, there is no way for a regular
143 expression to match a <newline>.
144 A null RE shall be equivalent to the last RE encountered.
146 Regular expressions are used in addresses to specify lines, and in some
148 commands (for example, the s substitute command) to specify portions of
149 a line to be substituted.
150 Addresses in ed
152 Addressing in ed relates to the current line. Generally, the current
153 line is the last line affected by a command. The current line number is
154 the address of the current line. If the edit buffer is not empty, the
155 initial value for the current line shall be the last line in the edit
156 buffer; otherwise, zero.
157 Addresses shall be constructed as follows:
159 1. The <period> character ('.') shall address the current line.
161 2. The <dollar-sign> character ('$') shall address the last line of
163 the edit buffer.
164 3. The positive decimal number n shall address the nth line of the
166 edit buffer.
167 4. The <apostrophe>-x character pair ("'x") shall address the line
169 marked with the mark name character x, which shall be a lowercase
170 letter from the portable character set. It shall be an error if the
171 character has not been set to mark a line or if the line that was
172 marked is not currently present in the edit buffer.
173 5. A BRE enclosed by <slash> characters ('/') shall address the first
175 line found by searching forwards from the line following the cur‐
176 rent line toward the end of the edit buffer and stopping at the
177 first line for which the line excluding the terminating <newline>
178 matches the BRE. The BRE consisting of a null BRE delimited by a
179 pair of <slash> characters shall address the next line for which
180 the line excluding the terminating <newline> matches the last BRE
181 encountered. In addition, the second <slash> can be omitted at the
182 end of a command line. Within the BRE, a <backslash>-<slash> pair
183 ("\/") shall represent a literal <slash> instead of the BRE delim‐
184 iter. If necessary, the search shall wrap around to the beginning
185 of the buffer and continue up to and including the current line, so
186 that the entire buffer is searched.
187 6. A BRE enclosed by <question-mark> characters ('?') shall address
189 the first line found by searching backwards from the line preceding
190 the current line toward the beginning of the edit buffer and stop‐
191 ping at the first line for which the line excluding the terminating
192 <newline> matches the BRE. The BRE consisting of a null BRE delim‐
193 ited by a pair of <question-mark> characters ("??") shall address
194 the previous line for which the line excluding the terminating
195 <newline> matches the last BRE encountered. In addition, the second
196 <question-mark> can be omitted at the end of a command line. Within
197 the BRE, a <backslash>-<question-mark> pair ("\?") shall represent
198 a literal <question-mark> instead of the BRE delimiter. If neces‐
199 sary, the search shall wrap around to the end of the buffer and
200 continue up to and including the current line, so that the entire
201 buffer is searched.
202 7. A <plus-sign> ('+') or <hyphen-minus> character ('-') followed by a
204 decimal number shall address the current line plus or minus the
205 number. A <plus-sign> or <hyphen-minus> character not followed by a
206 decimal number shall address the current line plus or minus 1.
207 Addresses can be followed by zero or more address offsets, optionally
209 <blank>-separated. Address offsets are constructed as follows:
210 * A <plus-sign> or <hyphen-minus> character followed by a decimal
212 number shall add or subtract, respectively, the indicated number of
213 lines to or from the address. A <plus-sign> or <hyphen-minus> char‐
214 acter not followed by a decimal number shall add or subtract 1 to
215 or from the address.
216 * A decimal number shall add the indicated number of lines to the
218 address.
219 It shall not be an error for an intermediate address value to be less
221 than zero or greater than the last line in the edit buffer. It shall be
222 an error for the final address value to be less than zero or greater
223 than the last line in the edit buffer. It shall be an error if a search
224 for a BRE fails to find a matching line.
225 Commands accept zero, one, or two addresses. If more than the required
227 number of addresses are provided to a command that requires zero
228 addresses, it shall be an error. Otherwise, if more than the required
229 number of addresses are provided to a command, the addresses specified
230 first shall be evaluated and then discarded until the maximum number of
231 valid addresses remain, for the specified command.
232 Addresses shall be separated from each other by a <comma> (',') or
234 <semicolon> character (';'). In the case of a <semicolon> separator,
235 the current line ('.') shall be set to the first address, and only
236 then will the second address be calculated. This feature can be used to
237 determine the starting line for forwards and backwards searches; see
238 rules 5. and 6.
239 Addresses can be omitted on either side of the <comma> or <semicolon>
241 separator, in which case the resulting address pairs shall be as fol‐
242 lows:
243 ┌──────────┬─────────────┐
245 │Specified │ Resulting │
246 ├──────────┼─────────────┤
247 │, │ 1 , $ │
248 │, addr │ 1 , addr │
249 │addr , │ addr , addr │
250 │; │ . ; $ │
251 │; addr │ . ; addr │
252 │addr ; │ addr ; addr │
253 └──────────┴─────────────┘
254 Any <blank> characters included between addresses, address separators,
255 or address offsets shall be ignored.
256 Commands in ed
258 In the following list of ed commands, the default addresses are shown
259 in parentheses. The number of addresses shown in the default shall be
260 the number expected by the command. The parentheses are not part of the
261 address; they show that the given addresses are the default.
262 It is generally invalid for more than one command to appear on a line.
264 However, any command (except e, E, f, q, Q, r, w, and !) can be suf‐
265 fixed by the letter l, n, or p; in which case, except for the l, n, and
266 p commands, the command shall be executed and then the new current line
267 shall be written as described below under the l, n, and p commands.
268 When an l, n, or p suffix is used with an l, n, or p command, the com‐
269 mand shall write to standard output as described below, but it is
270 unspecified whether the suffix writes the current line again in the
271 requested format or whether the suffix has no effect. For example, the
272 pl command (base p command with an l suffix) shall either write just
273 the current line or write it twice—once as specified for p and once as
274 specified for l. Also, the g, G, v, and V commands shall take a com‐
275 mand as a parameter.
276 Each address component can be preceded by zero or more <blank> charac‐
278 ters. The command letter can be preceded by zero or more <blank> char‐
279 acters. If a suffix letter (l, n, or p) is given, the application shall
280 ensure that it immediately follows the command.
281 The e, E, f, r, and w commands shall take an optional file parameter,
283 separated from the command letter by one or more <blank> characters.
284 If changes have been made in the buffer since the last w command that
286 wrote the entire buffer, ed shall warn the user if an attempt is made
287 to destroy the editor buffer via the e or q commands. The ed utility
288 shall write the string:
289 "?\n"
292 (followed by an explanatory message if help mode has been enabled via
294 the H command) to standard output and shall continue in command mode
295 with the current line number unchanged. If the e or q command is
296 repeated with no intervening command, it shall take effect.
297 If a terminal disconnect (see the Base Definitions volume of
299 POSIX.1‐2017, Chapter 11, General Terminal Interface, Modem Disconnect
300 and Closing a Device Terminal), is detected:
301 * If accompanied by a SIGHUP signal, the ed utility shall operate as
303 described in the ASYNCHRONOUS EVENTS section for a SIGHUP signal.
304 * If not accompanied by a SIGHUP signal, the ed utility shall act as
306 if an end-of-file had been detected on standard input.
307 If an end-of-file is detected on standard input:
309 * If the ed utility is in input mode, ed shall terminate input mode
311 and return to command mode. It is unspecified if any partially
312 entered lines (that is, input text without a terminating <newline>)
313 are discarded from the input text.
314 * If the ed utility is in command mode, it shall act as if a q com‐
316 mand had been entered.
317 If the closing delimiter of an RE or of a replacement string (for exam‐
319 ple, '/') in a g, G, s, v, or V command would be the last character
320 before a <newline>, that delimiter can be omitted, in which case the
321 addressed line shall be written. For example, the following pairs of
322 commands are equivalent:
323 s/s1/s2 s/s1/s2/p
326 g/s1 g/s1/p
327 ?s1 ?s1?
328 If an invalid command is entered, ed shall write the string:
330 "?\n"
333 (followed by an explanatory message if help mode has been enabled via
335 the H command) to standard output and shall continue in command mode
336 with the current line number unchanged.
337 Append Command
339 Synopsis:
340 (.)a
342 <text>
343 .
344 The a command shall read the given text and append it after the
346 addressed line; the current line number shall become the address of the
347 last inserted line or, if there were none, the addressed line. Address
348 0 shall be valid for this command; it shall cause the appended text to
349 be placed at the beginning of the buffer.
350 Change Command
352 Synopsis:
353 (.,.)c
355 <text>
356 .
357 The c command shall delete the addressed lines, then accept input text
359 that replaces these lines; the current line shall be set to the address
360 of the last line input; or, if there were none, at the line after the
361 last line deleted; if the lines deleted were originally at the end of
362 the buffer, the current line number shall be set to the address of the
363 new last line; if no lines remain in the buffer, the current line num‐
364 ber shall be set to zero. Address 0 shall be valid for this command; it
365 shall be interpreted as if address 1 were specified.
366 Delete Command
368 Synopsis:
369 (.,.)d
371 The d command shall delete the addressed lines from the buffer. The
373 address of the line after the last line deleted shall become the cur‐
374 rent line number; if the lines deleted were originally at the end of
375 the buffer, the current line number shall be set to the address of the
376 new last line; if no lines remain in the buffer, the current line num‐
377 ber shall be set to zero.
378 Edit Command
380 Synopsis:
381 e [file]
383 The e command shall delete the entire contents of the buffer and then
385 read in the file named by the pathname file. The current line number
386 shall be set to the address of the last line of the buffer. If no path‐
387 name is given, the currently remembered pathname, if any, shall be used
388 (see the f command). The number of bytes read shall be written to stan‐
389 dard output, unless the -s option was specified, in the following for‐
390 mat:
391 "%d\n", <number of bytes read>
394 The name file shall be remembered for possible use as a default path‐
396 name in subsequent e, E, r, and w commands. If file is replaced by '!',
397 the rest of the line shall be taken to be a shell command line whose
398 output is to be read. Such a shell command line shall not be remembered
399 as the current file. All marks shall be discarded upon the completion
400 of a successful e command. If the buffer has changed since the last
401 time the entire buffer was written, the user shall be warned, as
402 described previously.
403 Edit Without Checking Command
405 Synopsis:
406 E [file]
408 The E command shall possess all properties and restrictions of the e
410 command except that the editor shall not check to see whether any
411 changes have been made to the buffer since the last w command.
412 Filename Command
414 Synopsis:
415 f [file]
417 If file is given, the f command shall change the currently remembered
419 pathname to file; whether the name is changed or not, it shall then
420 write the (possibly new) currently remembered pathname to the standard
421 output in the following format:
422 "%s\n", <pathname>
425 The current line number shall be unchanged.
427 Global Command
429 Synopsis:
430 (1,$)g/RE/command list
432 In the g command, the first step shall be to mark every line for which
434 the line excluding the terminating <newline> matches the given RE.
435 Then, going sequentially from the beginning of the file to the end of
436 the file, the given command list shall be executed for each marked
437 line, with the current line number set to the address of that line. Any
438 line modified by the command list shall be unmarked. When the g command
439 completes, the current line number shall have the value assigned by the
440 last command in the command list. If there were no matching lines, the
441 current line number shall not be changed. A single command or the first
442 of a list of commands shall appear on the same line as the global com‐
443 mand. All lines of a multi-line list except the last line shall be
444 ended with a <backslash> preceding the terminating <newline>; the a, i,
445 and c commands and associated input are permitted. The '.' terminating
446 input mode can be omitted if it would be the last line of the command
447 list. An empty command list shall be equivalent to the p command. The
448 use of the g, G, v, V, and ! commands in the command list produces
449 undefined results. Any character other than <space> or <newline> can be
450 used instead of a <slash> to delimit the RE. Within the RE, the RE
451 delimiter itself can be used as a literal character if it is preceded
452 by a <backslash>.
453 Interactive Global Command
455 Synopsis:
456 (1,$)G/RE/
458 In the G command, the first step shall be to mark every line for which
460 the line excluding the terminating <newline> matches the given RE.
461 Then, for every such line, that line shall be written, the current line
462 number shall be set to the address of that line, and any one command
463 (other than one of the a, c, i, g, G, v, and V commands) shall be read
464 and executed. A <newline> shall act as a null command (causing no
465 action to be taken on the current line); an '&' shall cause the re-exe‐
466 cution of the most recent non-null command executed within the current
467 invocation of G. Note that the commands input as part of the execution
468 of the G command can address and affect any lines in the buffer. Any
469 line modified by the command shall be unmarked. The final value of the
470 current line number shall be the value set by the last command success‐
471 fully executed. (Note that the last command successfully executed shall
472 be the G command itself if a command fails or the null command is spec‐
473 ified.) If there were no matching lines, the current line number shall
474 not be changed. The G command can be terminated by a SIGINT signal. Any
475 character other than <space> or <newline> can be used instead of a
476 <slash> to delimit the RE and the replacement. Within the RE, the RE
477 delimiter itself can be used as a literal character if it is preceded
478 by a <backslash>.
479 Help Command
481 Synopsis:
482 h
484 The h command shall write a short message to standard output that
486 explains the reason for the most recent '?' notification. The current
487 line number shall be unchanged.
488 Help-Mode Command
490 Synopsis:
491 H
493 The H command shall cause ed to enter a mode in which help messages
495 (see the h command) shall be written to standard output for all subse‐
496 quent '?' notifications. The H command alternately shall turn this
497 mode on and off; it is initially off. If the help-mode is being turned
498 on, the H command also explains the previous '?' notification, if
499 there was one. The current line number shall be unchanged.
500 Insert Command
502 Synopsis:
503 (.)i
505 <text>
506 .
507 The i command shall insert the given text before the addressed line;
509 the current line is set to the last inserted line or, if there was
510 none, to the addressed line. This command differs from the a command
511 only in the placement of the input text. Address 0 shall be valid for
512 this command; it shall be interpreted as if address 1 were specified.
513 Join Command
515 Synopsis:
516 (.,.+1)j
518 The j command shall join contiguous lines by removing the appropriate
520 <newline> characters. If exactly one address is given, this command
521 shall do nothing. If lines are joined, the current line number shall be
522 set to the address of the joined line; otherwise, the current line num‐
523 ber shall be unchanged.
524 Mark Command
526 Synopsis:
527 (.)kx
529 The k command shall mark the addressed line with name x, which the
531 application shall ensure is a lowercase letter from the portable char‐
532 acter set. The address "'x" shall then refer to this line; the current
533 line number shall be unchanged.
534 List Command
536 Synopsis:
537 (.,.)l
539 The l command shall write to standard output the addressed lines in a
541 visually unambiguous form. The characters listed in the Base Defini‐
542 tions volume of POSIX.1‐2017, Table 5-1, Escape Sequences and Associ‐
543 ated Actions ('\\', '\a', '\b', '\f', '\r', '\t', '\v') shall be writ‐
544 ten as the corresponding escape sequence; the '\n' in that table is not
545 applicable. Non-printable characters not in the table shall be written
546 as one three-digit octal number (with a preceding <backslash> charac‐
547 ter) for each byte in the character (most significant byte first).
548 Long lines shall be folded, with the point of folding indicated by
550 <newline> preceded by a <backslash>; the length at which folding occurs
551 is unspecified, but should be appropriate for the output device. The
552 end of each line shall be marked with a '$', and '$' characters within
553 the text shall be written with a preceding <backslash>. An l command
554 can be appended to any other command other than e, E, f, q, Q, r, w, or
555 !. The current line number shall be set to the address of the last
556 line written.
557 Move Command
559 Synopsis:
560 (.,.)maddress
562 The m command shall reposition the addressed lines after the line
564 addressed by address. Address 0 shall be valid for address and cause
565 the addressed lines to be moved to the beginning of the buffer. It
566 shall be an error if address address falls within the range of moved
567 lines. The current line number shall be set to the address of the last
568 line moved.
569 Number Command
571 Synopsis:
572 (.,.)n
574 The n command shall write to standard output the addressed lines, pre‐
576 ceding each line by its line number and a <tab>; the current line num‐
577 ber shall be set to the address of the last line written. The n command
578 can be appended to any command other than e, E, f, q, Q, r, w, or !.
579 Print Command
581 Synopsis:
582 (.,.)p
584 The p command shall write to standard output the addressed lines; the
586 current line number shall be set to the address of the last line writ‐
587 ten. The p command can be appended to any command other than e, E, f,
588 q, Q, r, w, or !.
589 Prompt Command
591 Synopsis:
592 P
594 The P command shall cause ed to prompt with an <asterisk> ('*') (or
596 string, if -p is specified) for all subsequent commands. The P command
597 alternatively shall turn this mode on and off; it shall be initially on
598 if the -p option is specified; otherwise, off. The current line number
599 shall be unchanged.
600 Quit Command
602 Synopsis:
603 q
605 The q command shall cause ed to exit. If the buffer has changed since
607 the last time the entire buffer was written, the user shall be warned,
608 as described previously.
609 Quit Without Checking Command
611 Synopsis:
612 Q
614 The Q command shall cause ed to exit without checking whether changes
616 have been made in the buffer since the last w command.
617 Read Command
619 Synopsis:
620 ($)r [file]
622 The r command shall read in the file named by the pathname file and
624 append it after the addressed line. If no file argument is given, the
625 currently remembered pathname, if any, shall be used (see the e and f
626 commands). The currently remembered pathname shall not be changed
627 unless there is no remembered pathname. Address 0 shall be valid for r
628 and shall cause the file to be read at the beginning of the buffer. If
629 the read is successful, and -s was not specified, the number of bytes
630 read shall be written to standard output in the following format:
631 "%d\n", <number of bytes read>
634 The current line number shall be set to the address of the last line
636 read in. If file is replaced by '!', the rest of the line shall be
637 taken to be a shell command line whose output is to be read. Such a
638 shell command line shall not be remembered as the current pathname.
639 Substitute Command
641 Synopsis:
642 (.,.)s/RE/replacement/flags
644 The s command shall search each addressed line for an occurrence of the
646 specified RE and replace either the first or all (non-overlapped)
647 matched strings with the replacement; see the following description of
648 the g suffix. It is an error if the substitution fails on every
649 addressed line. Any character other than <space> or <newline> can be
650 used instead of a <slash> to delimit the RE and the replacement. Within
651 the RE, the RE delimiter itself can be used as a literal character if
652 it is preceded by a <backslash>. The current line shall be set to the
653 address of the last line on which a substitution occurred.
654 An <ampersand> ('&') appearing in the replacement shall be replaced by
656 the string matching the RE on the current line. The special meaning of
657 '&' in this context can be suppressed by preceding it by <backslash>.
658 As a more general feature, the characters '\n', where n is a digit,
659 shall be replaced by the text matched by the corresponding back-refer‐
660 ence expression. If the corresponding back-reference expression does
661 not match, then the characters '\n' shall be replaced by the empty
662 string. When the character '%' is the only character in the replace‐
663 ment, the replacement used in the most recent substitute command shall
664 be used as the replacement in the current substitute command; if there
665 was no previous substitute command, the use of '%' in this manner shall
666 be an error. The '%' shall lose its special meaning when it is in a
667 replacement string of more than one character or is preceded by a
668 <backslash>. For each <backslash> encountered in scanning replacement
669 from beginning to end, the following character shall lose its special
670 meaning (if any). It is unspecified what special meaning is given to
671 any character other than <backslash>, '&', '%', or digits.
672 A line can be split by substituting a <newline> into it. The applica‐
674 tion shall ensure it escapes the <newline> in the replacement by pre‐
675 ceding it by <backslash>. Such substitution cannot be done as part of
676 a g or v command list. The current line number shall be set to the
677 address of the last line on which a substitution is performed. If no
678 substitution is performed, the current line number shall be unchanged.
679 If a line is split, a substitution shall be considered to have been
680 performed on each of the new lines for the purpose of determining the
681 new current line number. A substitution shall be considered to have
682 been performed even if the replacement string is identical to the
683 string that it replaces.
684 The application shall ensure that the value of flags is zero or more
686 of:
687 count Substitute for the countth occurrence only of the RE found on
689 each addressed line.
690 g Globally substitute for all non-overlapping instances of the RE
692 rather than just the first one. If both g and count are speci‐
693 fied, the results are unspecified.
694 l Write to standard output the final line in which a substitution
696 was made. The line shall be written in the format specified for
697 the l command.
698 n Write to standard output the final line in which a substitution
700 was made. The line shall be written in the format specified for
701 the n command.
702 p Write to standard output the final line in which a substitution
704 was made. The line shall be written in the format specified for
705 the p command.
706 Copy Command
708 Synopsis:
709 (.,.)taddress
711 The t command shall be equivalent to the m command, except that a copy
713 of the addressed lines shall be placed after address address (which can
714 be 0); the current line number shall be set to the address of the last
715 line added.
716 Undo Command
718 Synopsis:
719 u
721 The u command shall nullify the effect of the most recent command that
723 modified anything in the buffer, namely the most recent a, c, d, g, i,
724 j, m, r, s, t, u, v, G, or V command. All changes made to the buffer by
725 a g, G, v, or V global command shall be undone as a single change; if
726 no changes were made by the global command (such as with g/RE/p), the u
727 command shall have no effect. The current line number shall be set to
728 the value it had immediately before the command being undone started.
729 Global Non-Matched Command
731 Synopsis:
732 (1,$)v/RE/command list
734 This command shall be equivalent to the global command g except that
736 the lines that are marked during the first step shall be those for
737 which the line excluding the terminating <newline> does not match the
738 RE.
739 Interactive Global Not-Matched Command
741 Synopsis:
742 (1,$)V/RE/
744 This command shall be equivalent to the interactive global command G
746 except that the lines that are marked during the first step shall be
747 those for which the line excluding the terminating <newline> does not
748 match the RE.
749 Write Command
751 Synopsis:
752 (1,$)w [file]
754 The w command shall write the addressed lines into the file named by
756 the pathname file. The command shall create the file, if it does not
757 exist, or shall replace the contents of the existing file. The cur‐
758 rently remembered pathname shall not be changed unless there is no
759 remembered pathname. If no pathname is given, the currently remembered
760 pathname, if any, shall be used (see the e and f commands); the current
761 line number shall be unchanged. If the command is successful, the num‐
762 ber of bytes written shall be written to standard output, unless the -s
763 option was specified, in the following format:
764 "%d\n", <number of bytes written>
767 If file begins with '!', the rest of the line shall be taken to be a
769 shell command line whose standard input shall be the addressed lines.
770 Such a shell command line shall not be remembered as the current path‐
771 name. This usage of the write command with '!' shall not be considered
772 as a ``last w command that wrote the entire buffer'', as described pre‐
773 viously; thus, this alone shall not prevent the warning to the user if
774 an attempt is made to destroy the editor buffer via the e or q com‐
775 mands.
776 Line Number Command
778 Synopsis:
779 ($)=
781 The line number of the addressed line shall be written to standard out‐
783 put in the following format:
784 "%d\n", <line number>
787 The current line number shall be unchanged by this command.
789 Shell Escape Command
791 Synopsis:
792 !command
794 The remainder of the line after the '!' shall be sent to the command
796 interpreter to be interpreted as a shell command line. Within the text
797 of that shell command line, the unescaped character '%' shall be
798 replaced with the remembered pathname; if a '!' appears as the first
799 character of the command, it shall be replaced with the text of the
800 previous shell command executed via '!'. Thus, "!!" shall repeat the
801 previous !command. If any replacements of '%' or '!' are performed,
802 the modified line shall be written to the standard output before com‐
803 mand is executed. The ! command shall write:
804 "!\n"
807 to standard output upon completion, unless the -s option is specified.
809 The current line number shall be unchanged.
810 Null Command
812 Synopsis:
813 (.+1)
815 An address alone on a line shall cause the addressed line to be writ‐
817 ten. A <newline> alone shall be equivalent to "+1p". The current line
818 number shall be set to the address of the written line.
819
821 The following exit values shall be returned:
822 0 Successful completion without any file or command errors.
824 >0 An error occurred.
826
828 When an error in the input script is encountered, or when an error is
829 detected that is a consequence of the data (not) present in the file or
830 due to an external condition such as a read or write error:
831 * If the standard input is a terminal device file, all input shall be
833 flushed, and a new command read.
834 * If the standard input is a regular file, ed shall terminate with a
836 non-zero exit status.
837 The following sections are informative.
839
841 Because of the extremely terse nature of the default error messages,
842 the prudent script writer begins the ed input commands with an H com‐
843 mand, so that if any errors do occur at least some clue as to the cause
844 is made available.
845 In earlier versions of this standard, an obsolescent - option was
847 described. This is no longer specified. Applications should use the -s
848 option. Using - as a file operand now produces unspecified results.
849 This allows implementations to continue to support the former required
850 behavior.
851
853 None.
854
856 The initial description of this utility was adapted from the SVID. It
857 contains some features not found in Version 7 or BSD-derived systems.
858 Some of the differences between the POSIX and BSD ed utilities include,
859 but need not be limited to:
860 * The BSD - option does not suppress the '!' prompt after a ! com‐
862 mand.
863 * BSD does not support the special meanings of the '%' and '!' char‐
865 acters within a ! command.
866 * BSD does not support the addresses ';' and ','.
868 * BSD allows the command/suffix pairs pp, ll, and so on, which are
870 unspecified in this volume of POSIX.1‐2017.
871 * BSD does not support the '!' character part of the e, r, or w com‐
873 mands.
874 * A failed g command in BSD sets the line number to the last line
876 searched if there are no matches.
877 * BSD does not default the command list to the p command.
879 * BSD does not support the G, h, H, n, or V commands.
881 * On BSD, if there is no inserted text, the insert command changes
883 the current line to the referenced line -1; that is, the line
884 before the specified line.
885 * On BSD, the join command with only a single address changes the
887 current line to that address.
888 * BSD does not support the P command; moreover, in BSD it is synony‐
890 mous with the p command.
891 * BSD does not support the undo of the commands j, m, r, s, or t.
893 * The Version 7 ed command W, and the BSD ed commands W, wq, and z
895 are not present in this volume of POSIX.1‐2017.
896 The -s option was added to allow the functionality of the removed -
898 option in a manner compatible with the Utility Syntax Guidelines.
899 In early proposals there was a limit, {ED_FILE_MAX}, that described the
901 historical limitations of some ed utilities in their handling of large
902 files; some of these have had problems with files larger than 100000
903 bytes. It was this limitation that prompted much of the desire to
904 include a split command in this volume of POSIX.1‐2017. Since this
905 limit was removed, this volume of POSIX.1‐2017 requires that implemen‐
906 tations document the file size limits imposed by ed in the conformance
907 document. The limit {ED_LINE_MAX} was also removed; therefore, the
908 global limit {LINE_MAX} is used for input and output lines.
909 The manner in which the l command writes non-printable characters was
911 changed to avoid the historical backspace-overstrike method. On video
912 display terminals, the overstrike is ambiguous because most terminals
913 simply replace overstruck characters, making the l format not useful
914 for its intended purpose of unambiguously understanding the content of
915 the line. The historical <backslash>-escapes were also ambiguous. (The
916 string "a\0011" could represent a line containing those six characters
917 or a line containing the three characters 'a', a byte with a binary
918 value of 1, and a 1.) In the format required here, a <backslash>
919 appearing in the line is written as "\\" so that the output is truly
920 unambiguous. The method of marking the ends of lines was adopted from
921 the ex editor and is required for any line ending in <space> charac‐
922 ters; the '$' is placed on all lines so that a real '$' at the end of a
923 line cannot be misinterpreted.
924 Earlier versions of this standard allowed for implementations with
926 bytes other than eight bits, but this has been modified in this ver‐
927 sion.
928 The description of how a NUL is written was removed. The NUL character
930 cannot be in text files, and this volume of POSIX.1‐2017 should not
931 dictate behavior in the case of undefined, erroneous input.
932 Unlike some of the other editing utilities, the filenames accepted by
934 the E, e, R, and r commands are not patterns.
935 Early proposals stated that the -p option worked only when standard
937 input was associated with a terminal device. This has been changed to
938 conform to historical implementations, thereby allowing applications to
939 interpose themselves between a user and the ed utility.
940 The form of the substitute command that uses the n suffix was limited
942 in some historical documentation (where this was described incorrectly
943 as ``backreferencing''). This limit has been omitted because there is
944 no reason why an editor processing lines of {LINE_MAX} length should
945 have this restriction. The command s/x/X/2047 should be able to substi‐
946 tute the 2047th occurrence of 'x' on a line.
947 The use of printing commands with printing suffixes (such as pn, lp,
949 and so on) was made unspecified because BSD-based systems allow this,
950 whereas System V does not.
951 Some BSD-based systems exit immediately upon receipt of end-of-file if
953 all of the lines in the file have been deleted. Since this volume of
954 POSIX.1‐2017 refers to the q command in this instance, such behavior is
955 not allowed.
956 Some historical implementations returned exit status zero even if com‐
958 mand errors had occurred; this is not allowed by this volume of
959 POSIX.1‐2017.
960 Some historical implementations contained a bug that allowed a single
962 <period> to be entered in input mode as <backslash> <period> <newline>.
963 This is not allowed by ed because there is no description of escaping
964 any of the characters in input mode; <backslash> characters are entered
965 into the buffer exactly as typed. The typical method of entering a sin‐
966 gle <period> has been to precede it with another character and then use
967 the substitute command to delete that character.
968 It is difficult under some modes of some versions of historical operat‐
970 ing system terminal drivers to distinguish between an end-of-file con‐
971 dition and terminal disconnect. POSIX.1‐2008 does not require implemen‐
972 tations to distinguish between the two situations, which permits his‐
973 torical implementations of the ed utility on historical platforms to
974 conform. Implementations are encouraged to distinguish between the two,
975 if possible, and take appropriate action on terminal disconnect.
976 Historically, ed accepted a zero address for the a and r commands in
978 order to insert text at the start of the edit buffer. When the buffer
979 was empty the command .= returned zero. POSIX.1‐2008 requires confor‐
980 mance to historical practice.
981 For consistency with the a and r commands and better user functional‐
983 ity, the i and c commands must also accept an address of 0, in which
984 case 0i is treated as 1i and likewise for the c command.
985 All of the following are valid addresses:
987 +++ Three lines after the current line.
989 /pattern/- One line before the next occurrence of pattern.
991 -2 Two lines before the current line.
993 3 ---- 2 Line one (note the intermediate negative address).
995 1 2 3 Line six.
997 Any number of addresses can be provided to commands taking addresses;
999 for example, "1,2,3,4,5p" prints lines 4 and 5, because two is the
1000 greatest valid number of addresses accepted by the print command. This,
1001 in combination with the <semicolon> delimiter, permits users to create
1002 commands based on ordered patterns in the file. For example, the com‐
1003 mand "3;/foo/;+2p" will display the first line after line 3 that con‐
1004 tains the pattern foo, plus the next two lines. Note that the address
1005 "3;" must still be evaluated before being discarded, because the search
1006 origin for the "/foo/" command depends on this.
1007 Historically, ed disallowed address chains, as discussed above, con‐
1009 sisting solely of <comma> or <semicolon> separators; for example, ",,,"
1010 or ";;;" were considered an error. For consistency of address specifi‐
1011 cation, this restriction is removed. The following table lists some of
1012 the address forms now possible:
1013 ┌────────┬───────┬───────┬────────────┬───────────────────────┐
1015 │Address │ Addr1 │ Addr2 │ Status │ Comment │
1016 ├────────┼───────┼───────┼────────────┼───────────────────────┤
1017 │7, │ 7 │ 7 │ Historical │ │
1018 │7,5, │ 5 │ 5 │ Historical │ │
1019 │7,5,9 │ 5 │ 9 │ Historical │ │
1020 │7,9 │ 7 │ 9 │ Historical │ │
1021 │7,+ │ 7 │ 8 │ Historical │ │
1022 │, │ 1 │ $ │ Historical │ │
1023 │,7 │ 1 │ 7 │ Extension │ │
1024 │,, │ $ │ $ │ Extension │ │
1025 │,; │ $ │ $ │ Extension │ │
1026 │7; │ 7 │ 7 │ Historical │ │
1027 │7;5; │ 5 │ 5 │ Historical │ │
1028 │7;5;9 │ 5 │ 9 │ Historical │ │
1029 │7;5,9 │ 5 │ 9 │ Historical │ │
1030 │7;$;4 │ $ │ 4 │ Historical │ Valid, but erroneous. │
1031 │7;9 │ 7 │ 9 │ Historical │ │
1032 │7;+ │ 7 │ 8 │ Historical │ │
1033 │; │ . │ $ │ Historical │ │
1034 │;7 │ . │ 7 │ Extension │ │
1035 │;; │ $ │ $ │ Extension │ │
1036 │;, │ $ │ $ │ Extension │ │
1037 └────────┴───────┴───────┴────────────┴───────────────────────┘
1038 Historically, ed accepted the '^' character as an address, in which
1039 case it was identical to the <hyphen-minus> character. POSIX.1‐2008
1040 does not require or prohibit this behavior.
1041
1043 None.
1044
1046 Section 1.4, Utility Description Defaults, ex, sed, sh, vi
1047 The Base Definitions volume of POSIX.1‐2017, Table 5-1, Escape
1049 Sequences and Associated Actions, Chapter 8, Environment Variables,
1050 Section 9.3, Basic Regular Expressions, Chapter 11, General Terminal
1051 Interface, Section 12.2, Utility Syntax Guidelines
1052
1054 Portions of this text are reprinted and reproduced in electronic form
1055 from IEEE Std 1003.1-2017, Standard for Information Technology -- Por‐
1056 table Operating System Interface (POSIX), The Open Group Base Specifi‐
1057 cations Issue 7, 2018 Edition, Copyright (C) 2018 by the Institute of
1058 Electrical and Electronics Engineers, Inc and The Open Group. In the
1059 event of any discrepancy between this version and the original IEEE and
1060 The Open Group Standard, the original IEEE and The Open Group Standard
1061 is the referee document. The original Standard can be obtained online
1062 at http://www.opengroup.org/unix/online.html .
1063 Any typographical or formatting errors that appear in this page are
1065 most likely to have been introduced during the conversion of the source
1066 files to man page format. To report such errors, see https://www.ker‐
1067 nel.org/doc/man-pages/reporting_bugs.html .
1068IEEE/The Open Group 2017 ED(1P)