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
13 ed — edit text
14
16 ed [−p string] [−s] [file]
17
19 The ed utility is a line-oriented text editor that uses two modes: com‐
20 mand mode and input mode. In command mode the input characters shall
21 be interpreted as commands, and in input mode they shall be interpreted
22 as text. See the EXTENDED DESCRIPTION section.
23 If an operand is '−', the results are unspecified.
25
27 The ed utility shall conform to the Base Definitions volume of
28 POSIX.1‐2008, Section 12.2, Utility Syntax Guidelines, except for the
29 unspecified usage of '−'.
30 The following options shall be supported:
32 −p string Use string as the prompt string when in command mode. By
34 default, there shall be no prompt string.
35 −s Suppress the writing of byte counts by e, E, r, and w com‐
37 mands and of the '!' prompt after a !command.
38
40 The following operand shall be supported:
41 file If the file argument is given, ed shall simulate an e command
43 on the file named by the pathname, file, before accepting
44 commands from the standard input.
45
47 The standard input shall be a text file consisting of commands, as
48 described in the EXTENDED DESCRIPTION section.
49
51 The input files shall be text files.
52
54 The following environment variables shall affect the execution of ed:
55 HOME Determine the pathname of the user's home directory.
57 LANG Provide a default value for the internationalization vari‐
59 ables that are unset or null. (See the Base Definitions vol‐
60 ume of POSIX.1‐2008, Section 8.2, Internationalization Vari‐
61 ables for the precedence of internationalization variables
62 used to determine the values of locale categories.)
63 LC_ALL If set to a non-empty string value, override the values of
65 all the other internationalization variables.
66 LC_COLLATE
68 Determine the locale for the behavior of ranges, equivalence
69 classes, and multi-character collating elements within regu‐
70 lar expressions.
71 LC_CTYPE Determine the locale for the interpretation of sequences of
73 bytes of text data as characters (for example, single-byte as
74 opposed to multi-byte characters in arguments and input
75 files) and the behavior of character classes within regular
76 expressions.
77 LC_MESSAGES
79 Determine the locale that should be used to affect the format
80 and contents of diagnostic messages written to standard error
81 and informative messages written to standard output.
82 NLSPATH Determine the location of message catalogs for the processing
84 of LC_MESSAGES.
85
87 The ed utility shall take the standard action for all signals (see the
88 ASYNCHRONOUS EVENTS section in Section 1.4, Utility Description
89 Defaults) with the following exceptions:
90 SIGINT The ed utility shall interrupt its current activity, write
92 the string "?\n" to standard output, and return to command
93 mode (see the EXTENDED DESCRIPTION section).
94 SIGHUP If the buffer is not empty and has changed since the last
96 write, the ed utility shall attempt to write a copy of the
97 buffer in a file. First, the file named ed.hup in the current
98 directory shall be used; if that fails, the file named ed.hup
99 in the directory named by the HOME environment variable shall
100 be used. In any case, the ed utility shall exit without writ‐
101 ing the file to the currently remembered pathname and without
102 returning to command mode.
103 SIGQUIT The ed utility shall ignore this event.
105
107 Various editing commands and the prompting feature (see −p) write to
108 standard output, as described in the EXTENDED DESCRIPTION section.
109
111 The standard error shall be used only for diagnostic messages.
112
114 The output files shall be text files whose formats are dependent on the
115 editing commands given.
116
118 The ed utility shall operate on a copy of the file it is editing;
119 changes made to the copy shall have no effect on the file until a w
120 (write) command is given. The copy of the text is called the buffer.
121 Commands to ed have a simple and regular structure: zero, one, or two
123 addresses followed by a single-character command, possibly followed by
124 parameters to that command. These addresses specify one or more lines
125 in the buffer. Every command that requires addresses has default
126 addresses, so that the addresses very often can be omitted. If the −p
127 option is specified, the prompt string shall be written to standard
128 output before each command is read.
129 In general, only one command can appear on a line. Certain commands
131 allow text to be input. This text is placed in the appropriate place in
132 the buffer. While ed is accepting text, it is said to be in input mode.
133 In this mode, no commands shall be recognized; all input is merely col‐
134 lected. Input mode is terminated by entering a line consisting of two
135 characters: a <period> ('.') followed by a <newline>. This line is
136 not considered part of the input text.
137 Regular Expressions in ed
139 The ed utility shall support basic regular expressions, as described in
140 the Base Definitions volume of POSIX.1‐2008, Section 9.3, Basic Regular
141 Expressions. Since regular expressions in ed are always matched
142 against single lines (excluding the terminating <newline> characters),
143 never against any larger section of text, there is no way for a regular
144 expression to match a <newline>.
145 A null RE shall be equivalent to the last RE encountered.
147 Regular expressions are used in addresses to specify lines, and in some
149 commands (for example, the s substitute command) to specify portions of
150 a line to be substituted.
151 Addresses in ed
153 Addressing in ed relates to the current line. Generally, the current
154 line is the last line affected by a command. The current line number is
155 the address of the current line. If the edit buffer is not empty, the
156 initial value for the current line shall be the last line in the edit
157 buffer; otherwise, zero.
158 Addresses shall be constructed as follows:
160 1. The <period> character ('.') shall address the current line.
162 2. The <dollar-sign> character ('$') shall address the last line of
164 the edit buffer.
165 3. The positive decimal number n shall address the nth line of the
167 edit buffer.
168 4. The <apostrophe>-x character pair ("'x") shall address the line
170 marked with the mark name character x, which shall be a lowercase
171 letter from the portable character set. It shall be an error if the
172 character has not been set to mark a line or if the line that was
173 marked is not currently present in the edit buffer.
174 5. A BRE enclosed by <slash> characters ('/') shall address the first
176 line found by searching forwards from the line following the cur‐
177 rent line toward the end of the edit buffer and stopping at the
178 first line for which the line excluding the terminating <newline>
179 matches the BRE. The BRE consisting of a null BRE delimited by a
180 pair of <slash> characters shall address the next line for which
181 the line excluding the terminating <newline> matches the last BRE
182 encountered. In addition, the second <slash> can be omitted at the
183 end of a command line. Within the BRE, a <backslash>-<slash> pair
184 ("\/") shall represent a literal <slash> instead of the BRE delim‐
185 iter. If necessary, the search shall wrap around to the beginning
186 of the buffer and continue up to and including the current line, so
187 that the entire buffer is searched.
188 6. A BRE enclosed by <question-mark> characters ('?') shall address
190 the first line found by searching backwards from the line preceding
191 the current line toward the beginning of the edit buffer and stop‐
192 ping at the first line for which the line excluding the terminating
193 <newline> matches the BRE. The BRE consisting of a null BRE delim‐
194 ited by a pair of <question-mark> characters ("??") shall address
195 the previous line for which the line excluding the terminating
196 <newline> matches the last BRE encountered. In addition, the second
197 <question-mark> can be omitted at the end of a command line. Within
198 the BRE, a <backslash>-<question-mark> pair ("\?") shall represent
199 a literal <question-mark> instead of the BRE delimiter. If neces‐
200 sary, the search shall wrap around to the end of the buffer and
201 continue up to and including the current line, so that the entire
202 buffer is searched.
203 7. A <plus-sign> ('+') or <hyphen> character ('−') followed by a deci‐
205 mal number shall address the current line plus or minus the number.
206 A <plus-sign> or <hyphen> character not followed by a decimal num‐
207 ber shall address the current line plus or minus 1.
208 Addresses can be followed by zero or more address offsets, optionally
210 <blank>-separated. Address offsets are constructed as follows:
211 * A <plus-sign> or <hyphen> character followed by a decimal number
213 shall add or subtract, respectively, the indicated number of lines
214 to or from the address. A <plus-sign> or <hyphen> character not
215 followed by a decimal number shall add or subtract 1 to or from the
216 address.
217 * A decimal number shall add the indicated number of lines to the
219 address.
220 It shall not be an error for an intermediate address value to be less
222 than zero or greater than the last line in the edit buffer. It shall be
223 an error for the final address value to be less than zero or greater
224 than the last line in the edit buffer. It shall be an error if a search
225 for a BRE fails to find a matching line.
226 Commands accept zero, one, or two addresses. If more than the required
228 number of addresses are provided to a command that requires zero
229 addresses, it shall be an error. Otherwise, if more than the required
230 number of addresses are provided to a command, the addresses specified
231 first shall be evaluated and then discarded until the maximum number of
232 valid addresses remain, for the specified command.
233 Addresses shall be separated from each other by a <comma> (',') or
235 <semicolon> character (';'). In the case of a <semicolon> separator,
236 the current line ('.') shall be set to the first address, and only
237 then will the second address be calculated. This feature can be used to
238 determine the starting line for forwards and backwards searches; see
239 rules 5. and 6.
240 Addresses can be omitted on either side of the <comma> or <semicolon>
242 separator, in which case the resulting address pairs shall be as fol‐
243 lows:
244 ┌──────────┬─────────────┐
246 │Specified │ Resulting │
247 ├──────────┼─────────────┤
248 │, │ 1 , $ │
249 │, addr │ 1 , addr │
250 │addr , │ addr , addr │
251 │; │ . ; $ │
252 │; addr │ . ; addr │
253 │addr ; │ addr ; addr │
254 └──────────┴─────────────┘
255 Any <blank> characters included between addresses, address separators,
256 or address offsets shall be ignored.
257 Commands in ed
259 In the following list of ed commands, the default addresses are shown
260 in parentheses. The number of addresses shown in the default shall be
261 the number expected by the command. The parentheses are not part of the
262 address; they show that the given addresses are the default.
263 It is generally invalid for more than one command to appear on a line.
265 However, any command (except e, E, f, q, Q, r, w, and !) can be suf‐
266 fixed by the letter l, n, or p; in which case, except for the l, n, and
267 p commands, the command shall be executed and then the new current line
268 shall be written as described below under the l, n, and p commands.
269 When an l, n, or p suffix is used with an l, n, or p command, the com‐
270 mand shall write to standard output as described below, but it is
271 unspecified whether the suffix writes the current line again in the
272 requested format or whether the suffix has no effect. For example, the
273 pl command (base p command with an l suffix) shall either write just
274 the current line or write it twice—once as specified for p and once as
275 specified for l. Also, the g, G, v, and V commands shall take a com‐
276 mand as a parameter.
277 Each address component can be preceded by zero or more <blank> charac‐
279 ters. The command letter can be preceded by zero or more <blank> char‐
280 acters. If a suffix letter (l, n, or p) is given, the application shall
281 ensure that it immediately follows the command.
282 The e, E, f, r, and w commands shall take an optional file parameter,
284 separated from the command letter by one or more <blank> characters.
285 If changes have been made in the buffer since the last w command that
287 wrote the entire buffer, ed shall warn the user if an attempt is made
288 to destroy the editor buffer via the e or q commands. The ed utility
289 shall write the string:
290 "?\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.1‐2008, 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
325 g/s1 g/s1/p
326 ?s1 ?s1?
327 If an invalid command is entered, ed shall write the string:
329 "?\n"
331 (followed by an explanatory message if help mode has been enabled via
333 the H command) to standard output and shall continue in command mode
334 with the current line number unchanged.
335 Append Command
337 Synopsis:
338 (.)a
339 <text>
340 .
341 The a command shall read the given text and append it after the
343 addressed line; the current line number shall become the address of the
344 last inserted line or, if there were none, the addressed line. Address
345 0 shall be valid for this command; it shall cause the appended text to
346 be placed at the beginning of the buffer.
347 Change Command
349 Synopsis:
350 (.,.)c
351 <text>
352 .
353 The c command shall delete the addressed lines, then accept input text
355 that replaces these lines; the current line shall be set to the address
356 of the last line input; or, if there were none, at the line after the
357 last line deleted; if the lines deleted were originally at the end of
358 the buffer, the current line number shall be set to the address of the
359 new last line; if no lines remain in the buffer, the current line num‐
360 ber shall be set to zero. Address 0 shall be valid for this command; it
361 shall be interpreted as if address 1 were specified.
362 Delete Command
364 Synopsis:
365 (.,.)d
366 The d command shall delete the addressed lines from the buffer. The
368 address of the line after the last line deleted shall become the cur‐
369 rent line number; if the lines deleted were originally at the end of
370 the buffer, the current line number shall be set to the address of the
371 new last line; if no lines remain in the buffer, the current line num‐
372 ber shall be set to zero.
373 Edit Command
375 Synopsis:
376 e [file]
377 The e command shall delete the entire contents of the buffer and then
379 read in the file named by the pathname file. The current line number
380 shall be set to the address of the last line of the buffer. If no path‐
381 name is given, the currently remembered pathname, if any, shall be used
382 (see the f command). The number of bytes read shall be written to stan‐
383 dard output, unless the −s option was specified, in the following for‐
384 mat:
385 "%d\n", <number of bytes read>
387 The name file shall be remembered for possible use as a default path‐
389 name in subsequent e, E, r, and w commands. If file is replaced by '!',
390 the rest of the line shall be taken to be a shell command line whose
391 output is to be read. Such a shell command line shall not be remembered
392 as the current file. All marks shall be discarded upon the completion
393 of a successful e command. If the buffer has changed since the last
394 time the entire buffer was written, the user shall be warned, as
395 described previously.
396 Edit Without Checking Command
398 Synopsis:
399 E [file]
400 The E command shall possess all properties and restrictions of the e
402 command except that the editor shall not check to see whether any
403 changes have been made to the buffer since the last w command.
404 Filename Command
406 Synopsis:
407 f [file]
408 If file is given, the f command shall change the currently remembered
410 pathname to file; whether the name is changed or not, it shall then
411 write the (possibly new) currently remembered pathname to the standard
412 output in the following format:
413 "%s\n", <pathname>
415 The current line number shall be unchanged.
417 Global Command
419 Synopsis:
420 (1,$)g/RE/command list
421 In the g command, the first step shall be to mark every line for which
423 the line excluding the terminating <newline> matches the given RE.
424 Then, going sequentially from the beginning of the file to the end of
425 the file, the given command list shall be executed for each marked
426 line, with the current line number set to the address of that line. Any
427 line modified by the command list shall be unmarked. When the g command
428 completes, the current line number shall have the value assigned by the
429 last command in the command list. If there were no matching lines, the
430 current line number shall not be changed. A single command or the first
431 of a list of commands shall appear on the same line as the global com‐
432 mand. All lines of a multi-line list except the last line shall be
433 ended with a <backslash> preceding the terminating <newline>; the a, i,
434 and c commands and associated input are permitted. The '.' terminating
435 input mode can be omitted if it would be the last line of the command
436 list. An empty command list shall be equivalent to the p command. The
437 use of the g, G, v, V, and ! commands in the command list produces
438 undefined results. Any character other than <space> or <newline> can be
439 used instead of a <slash> to delimit the RE. Within the RE, the RE
440 delimiter itself can be used as a literal character if it is preceded
441 by a <backslash>.
442 Interactive Global Command
444 Synopsis:
445 (1,$)G/RE/
446 In the G command, the first step shall be to mark every line for which
448 the line excluding the terminating <newline> matches the given RE.
449 Then, for every such line, that line shall be written, the current line
450 number shall be set to the address of that line, and any one command
451 (other than one of the a, c, i, g, G, v, and V commands) shall be read
452 and executed. A <newline> shall act as a null command (causing no
453 action to be taken on the current line); an '&' shall cause the re-exe‐
454 cution of the most recent non-null command executed within the current
455 invocation of G. Note that the commands input as part of the execution
456 of the G command can address and affect any lines in the buffer. Any
457 line modified by the command shall be unmarked. The final value of the
458 current line number shall be the value set by the last command success‐
459 fully executed. (Note that the last command successfully executed shall
460 be the G command itself if a command fails or the null command is spec‐
461 ified.) If there were no matching lines, the current line number shall
462 not be changed. The G command can be terminated by a SIGINT signal. Any
463 character other than <space> or <newline> can be used instead of a
464 <slash> to delimit the RE and the replacement. Within the RE, the RE
465 delimiter itself can be used as a literal character if it is preceded
466 by a <backslash>.
467 Help Command
469 Synopsis:
470 h
471 The h command shall write a short message to standard output that
473 explains the reason for the most recent '?' notification. The current
474 line number shall be unchanged.
475 Help-Mode Command
477 Synopsis:
478 H
479 The H command shall cause ed to enter a mode in which help messages
481 (see the h command) shall be written to standard output for all subse‐
482 quent '?' notifications. The H command alternately shall turn this
483 mode on and off; it is initially off. If the help-mode is being turned
484 on, the H command also explains the previous '?' notification, if
485 there was one. The current line number shall be unchanged.
486 Insert Command
488 Synopsis:
489 (.)i
490 <text>
491 .
492 The i command shall insert the given text before the addressed line;
494 the current line is set to the last inserted line or, if there was
495 none, to the addressed line. This command differs from the a command
496 only in the placement of the input text. Address 0 shall be valid for
497 this command; it shall be interpreted as if address 1 were specified.
498 Join Command
500 Synopsis:
501 (.,.+1)j
502 The j command shall join contiguous lines by removing the appropriate
504 <newline> characters. If exactly one address is given, this command
505 shall do nothing. If lines are joined, the current line number shall be
506 set to the address of the joined line; otherwise, the current line num‐
507 ber shall be unchanged.
508 Mark Command
510 Synopsis:
511 (.)kx
512 The k command shall mark the addressed line with name x, which the
514 application shall ensure is a lowercase letter from the portable char‐
515 acter set. The address "'x" shall then refer to this line; the current
516 line number shall be unchanged.
517 List Command
519 Synopsis:
520 (.,.)l
521 The l command shall write to standard output the addressed lines in a
523 visually unambiguous form. The characters listed in the Base Defini‐
524 tions volume of POSIX.1‐2008, Table 5-1, Escape Sequences and Associ‐
525 ated Actions ('\\', '\a', '\b', '\f', '\r', '\t', '\v') shall be writ‐
526 ten as the corresponding escape sequence; the '\n' in that table is not
527 applicable. Non-printable characters not in the table shall be written
528 as one three-digit octal number (with a preceding <backslash> charac‐
529 ter) for each byte in the character (most significant byte first).
530 Long lines shall be folded, with the point of folding indicated by
532 <newline> preceded by a <backslash>; the length at which folding occurs
533 is unspecified, but should be appropriate for the output device. The
534 end of each line shall be marked with a '$', and '$' characters within
535 the text shall be written with a preceding <backslash>. An l command
536 can be appended to any other command other than e, E, f, q, Q, r, w, or
537 !. The current line number shall be set to the address of the last
538 line written.
539 Move Command
541 Synopsis:
542 (.,.)maddress
543 The m command shall reposition the addressed lines after the line
545 addressed by address. Address 0 shall be valid for address and cause
546 the addressed lines to be moved to the beginning of the buffer. It
547 shall be an error if address address falls within the range of moved
548 lines. The current line number shall be set to the address of the last
549 line moved.
550 Number Command
552 Synopsis:
553 (.,.)n
554 The n command shall write to standard output the addressed lines, pre‐
556 ceding each line by its line number and a <tab>; the current line num‐
557 ber shall be set to the address of the last line written. The n command
558 can be appended to any command other than e, E, f, q, Q, r, w, or !.
559 Print Command
561 Synopsis:
562 (.,.)p
563 The p command shall write to standard output the addressed lines; the
565 current line number shall be set to the address of the last line writ‐
566 ten. The p command can be appended to any command other than e, E, f,
567 q, Q, r, w, or !.
568 Prompt Command
570 Synopsis:
571 P
572 The P command shall cause ed to prompt with an <asterisk> ('*') (or
574 string, if −p is specified) for all subsequent commands. The P command
575 alternatively shall turn this mode on and off; it shall be initially on
576 if the −p option is specified; otherwise, off. The current line number
577 shall be unchanged.
578 Quit Command
580 Synopsis:
581 q
582 The q command shall cause ed to exit. If the buffer has changed since
584 the last time the entire buffer was written, the user shall be warned,
585 as described previously.
586 Quit Without Checking Command
588 Synopsis:
589 Q
590 The Q command shall cause ed to exit without checking whether changes
592 have been made in the buffer since the last w command.
593 Read Command
595 Synopsis:
596 ($)r [file]
597 The r command shall read in the file named by the pathname file and
599 append it after the addressed line. If no file argument is given, the
600 currently remembered pathname, if any, shall be used (see the e and f
601 commands). The currently remembered pathname shall not be changed
602 unless there is no remembered pathname. Address 0 shall be valid for r
603 and shall cause the file to be read at the beginning of the buffer. If
604 the read is successful, and −s was not specified, the number of bytes
605 read shall be written to standard output in the following format:
606 "%d\n", <number of bytes read>
608 The current line number shall be set to the address of the last line
610 read in. If file is replaced by '!', the rest of the line shall be
611 taken to be a shell command line whose output is to be read. Such a
612 shell command line shall not be remembered as the current pathname.
613 Substitute Command
615 Synopsis:
616 (.,.)s/RE/replacement/flags
617 The s command shall search each addressed line for an occurrence of the
619 specified RE and replace either the first or all (non-overlapped)
620 matched strings with the replacement; see the following description of
621 the g suffix. It is an error if the substitution fails on every
622 addressed line. Any character other than <space> or <newline> can be
623 used instead of a <slash> to delimit the RE and the replacement. Within
624 the RE, the RE delimiter itself can be used as a literal character if
625 it is preceded by a <backslash>. The current line shall be set to the
626 address of the last line on which a substitution occurred.
627 An <ampersand> ('&') appearing in the replacement shall be replaced by
629 the string matching the RE on the current line. The special meaning of
630 '&' in this context can be suppressed by preceding it by <backslash>.
631 As a more general feature, the characters '\n', where n is a digit,
632 shall be replaced by the text matched by the corresponding back-refer‐
633 ence expression. If the corresponding back-reference expression does
634 not match, then the characters '\n' shall be replaced by the empty
635 string. When the character '%' is the only character in the replace‐
636 ment, the replacement used in the most recent substitute command shall
637 be used as the replacement in the current substitute command; if there
638 was no previous substitute command, the use of '%' in this manner shall
639 be an error. The '%' shall lose its special meaning when it is in a
640 replacement string of more than one character or is preceded by a
641 <backslash>. For each <backslash> encountered in scanning replacement
642 from beginning to end, the following character shall lose its special
643 meaning (if any). It is unspecified what special meaning is given to
644 any character other than <backslash>, '&', '%', or digits.
645 A line can be split by substituting a <newline> into it. The applica‐
647 tion shall ensure it escapes the <newline> in the replacement by pre‐
648 ceding it by <backslash>. Such substitution cannot be done as part of
649 a g or v command list. The current line number shall be set to the
650 address of the last line on which a substitution is performed. If no
651 substitution is performed, the current line number shall be unchanged.
652 If a line is split, a substitution shall be considered to have been
653 performed on each of the new lines for the purpose of determining the
654 new current line number. A substitution shall be considered to have
655 been performed even if the replacement string is identical to the
656 string that it replaces.
657 The application shall ensure that the value of flags is zero or more
659 of:
660 count Substitute for the countth occurrence only of the RE found on
662 each addressed line.
663 g Globally substitute for all non-overlapping instances of the RE
665 rather than just the first one. If both g and count are speci‐
666 fied, the results are unspecified.
667 l Write to standard output the final line in which a substitution
669 was made. The line shall be written in the format specified for
670 the l command.
671 n Write to standard output the final line in which a substitution
673 was made. The line shall be written in the format specified for
674 the n command.
675 p Write to standard output the final line in which a substitution
677 was made. The line shall be written in the format specified for
678 the p command.
679 Copy Command
681 Synopsis:
682 (.,.)taddress
683 The t command shall be equivalent to the m command, except that a copy
685 of the addressed lines shall be placed after address address (which can
686 be 0); the current line number shall be set to the address of the last
687 line added.
688 Undo Command
690 Synopsis:
691 u
692 The u command shall nullify the effect of the most recent command that
694 modified anything in the buffer, namely the most recent a, c, d, g, i,
695 j, m, r, s, t, u, v, G, or V command. All changes made to the buffer by
696 a g, G, v, or V global command shall be undone as a single change; if
697 no changes were made by the global command (such as with g/RE/p), the u
698 command shall have no effect. The current line number shall be set to
699 the value it had immediately before the command being undone started.
700 Global Non-Matched Command
702 Synopsis:
703 (1,$)v/RE/command list
704 This command shall be equivalent to the global command g except that
706 the lines that are marked during the first step shall be those for
707 which the line excluding the terminating <newline> does not match the
708 RE.
709 Interactive Global Not-Matched Command
711 Synopsis:
712 (1,$)V/RE/
713 This command shall be equivalent to the interactive global command G
715 except that the lines that are marked during the first step shall be
716 those for which the line excluding the terminating <newline> does not
717 match the RE.
718 Write Command
720 Synopsis:
721 (1,$)w [file]
722 The w command shall write the addressed lines into the file named by
724 the pathname file. The command shall create the file, if it does not
725 exist, or shall replace the contents of the existing file. The cur‐
726 rently remembered pathname shall not be changed unless there is no
727 remembered pathname. If no pathname is given, the currently remembered
728 pathname, if any, shall be used (see the e and f commands); the current
729 line number shall be unchanged. If the command is successful, the num‐
730 ber of bytes written shall be written to standard output, unless the −s
731 option was specified, in the following format:
732 "%d\n", <number of bytes written>
734 If file begins with '!', the rest of the line shall be taken to be a
736 shell command line whose standard input shall be the addressed lines.
737 Such a shell command line shall not be remembered as the current path‐
738 name. This usage of the write command with '!' shall not be considered
739 as a ``last w command that wrote the entire buffer'', as described pre‐
740 viously; thus, this alone shall not prevent the warning to the user if
741 an attempt is made to destroy the editor buffer via the e or q com‐
742 mands.
743 Line Number Command
745 Synopsis:
746 ($)=
747 The line number of the addressed line shall be written to standard out‐
749 put in the following format:
750 "%d\n", <line number>
752 The current line number shall be unchanged by this command.
754 Shell Escape Command
756 Synopsis:
757 !command
758 The remainder of the line after the '!' shall be sent to the command
760 interpreter to be interpreted as a shell command line. Within the text
761 of that shell command line, the unescaped character '%' shall be
762 replaced with the remembered pathname; if a '!' appears as the first
763 character of the command, it shall be replaced with the text of the
764 previous shell command executed via '!'. Thus, "!!" shall repeat the
765 previous !command. If any replacements of '%' or '!' are performed,
766 the modified line shall be written to the standard output before com‐
767 mand is executed. The ! command shall write:
768 "!\n"
770 to standard output upon completion, unless the −s option is specified.
772 The current line number shall be unchanged.
773 Null Command
775 Synopsis:
776 (.+1)
777 An address alone on a line shall cause the addressed line to be writ‐
779 ten. A <newline> alone shall be equivalent to "+1p". The current line
780 number shall be set to the address of the written line.
781
783 The following exit values shall be returned:
784 0 Successful completion without any file or command errors.
786 >0 An error occurred.
788
790 When an error in the input script is encountered, or when an error is
791 detected that is a consequence of the data (not) present in the file or
792 due to an external condition such as a read or write error:
793 * If the standard input is a terminal device file, all input shall be
795 flushed, and a new command read.
796 * If the standard input is a regular file, ed shall terminate with a
798 non-zero exit status.
799 The following sections are informative.
801
803 Because of the extremely terse nature of the default error messages,
804 the prudent script writer begins the ed input commands with an H com‐
805 mand, so that if any errors do occur at least some clue as to the cause
806 is made available.
807 In earlier versions of this standard, an obsolescent − option was
809 described. This is no longer specified. Applications should use the −s
810 option. Using − as a file operand now produces unspecified results.
811 This allows implementations to continue to support the former required
812 behavior.
813
815 None.
816
818 The initial description of this utility was adapted from the SVID. It
819 contains some features not found in Version 7 or BSD-derived systems.
820 Some of the differences between the POSIX and BSD ed utilities include,
821 but need not be limited to:
822 * The BSD − option does not suppress the '!' prompt after a ! com‐
824 mand.
825 * BSD does not support the special meanings of the '%' and '!' char‐
827 acters within a ! command.
828 * BSD does not support the addresses ';' and ','.
830 * BSD allows the command/suffix pairs pp, ll, and so on, which are
832 unspecified in this volume of POSIX.1‐2008.
833 * BSD does not support the '!' character part of the e, r, or w com‐
835 mands.
836 * A failed g command in BSD sets the line number to the last line
838 searched if there are no matches.
839 * BSD does not default the command list to the p command.
841 * BSD does not support the G, h, H, n, or V commands.
843 * On BSD, if there is no inserted text, the insert command changes
845 the current line to the referenced line −1; that is, the line
846 before the specified line.
847 * On BSD, the join command with only a single address changes the
849 current line to that address.
850 * BSD does not support the P command; moreover, in BSD it is synony‐
852 mous with the p command.
853 * BSD does not support the undo of the commands j, m, r, s, or t.
855 * The Version 7 ed command W, and the BSD ed commands W, wq, and z
857 are not present in this volume of POSIX.1‐2008.
858 The −s option was added to allow the functionality of the removed −
860 option in a manner compatible with the Utility Syntax Guidelines.
861 In early proposals there was a limit, {ED_FILE_MAX}, that described the
863 historical limitations of some ed utilities in their handling of large
864 files; some of these have had problems with files larger than 100000
865 bytes. It was this limitation that prompted much of the desire to
866 include a split command in this volume of POSIX.1‐2008. Since this
867 limit was removed, this volume of POSIX.1‐2008 requires that implemen‐
868 tations document the file size limits imposed by ed in the conformance
869 document. The limit {ED_LINE_MAX} was also removed; therefore, the
870 global limit {LINE_MAX} is used for input and output lines.
871 The manner in which the l command writes non-printable characters was
873 changed to avoid the historical backspace-overstrike method. On video
874 display terminals, the overstrike is ambiguous because most terminals
875 simply replace overstruck characters, making the l format not useful
876 for its intended purpose of unambiguously understanding the content of
877 the line. The historical <backslash>-escapes were also ambiguous. (The
878 string "a\0011" could represent a line containing those six characters
879 or a line containing the three characters 'a', a byte with a binary
880 value of 1, and a 1.) In the format required here, a <backslash>
881 appearing in the line is written as "\\" so that the output is truly
882 unambiguous. The method of marking the ends of lines was adopted from
883 the ex editor and is required for any line ending in <space> charac‐
884 ters; the '$' is placed on all lines so that a real '$' at the end of a
885 line cannot be misinterpreted.
886 Earlier versions of this standard allowed for implementations with
888 bytes other than eight bits, but this has been modified in this ver‐
889 sion.
890 The description of how a NUL is written was removed. The NUL character
892 cannot be in text files, and this volume of POSIX.1‐2008 should not
893 dictate behavior in the case of undefined, erroneous input.
894 Unlike some of the other editing utilities, the filenames accepted by
896 the E, e, R, and r commands are not patterns.
897 Early proposals stated that the −p option worked only when standard
899 input was associated with a terminal device. This has been changed to
900 conform to historical implementations, thereby allowing applications to
901 interpose themselves between a user and the ed utility.
902 The form of the substitute command that uses the n suffix was limited
904 in some historical documentation (where this was described incorrectly
905 as ``backreferencing''). This limit has been omitted because there is
906 no reason why an editor processing lines of {LINE_MAX} length should
907 have this restriction. The command s/x/X/2047 should be able to substi‐
908 tute the 2047th occurrence of 'x' on a line.
909 The use of printing commands with printing suffixes (such as pn, lp,
911 and so on) was made unspecified because BSD-based systems allow this,
912 whereas System V does not.
913 Some BSD-based systems exit immediately upon receipt of end-of-file if
915 all of the lines in the file have been deleted. Since this volume of
916 POSIX.1‐2008 refers to the q command in this instance, such behavior is
917 not allowed.
918 Some historical implementations returned exit status zero even if com‐
920 mand errors had occurred; this is not allowed by this volume of
921 POSIX.1‐2008.
922 Some historical implementations contained a bug that allowed a single
924 <period> to be entered in input mode as <backslash> <period> <newline>.
925 This is not allowed by ed because there is no description of escaping
926 any of the characters in input mode; <backslash> characters are entered
927 into the buffer exactly as typed. The typical method of entering a sin‐
928 gle <period> has been to precede it with another character and then use
929 the substitute command to delete that character.
930 It is difficult under some modes of some versions of historical operat‐
932 ing system terminal drivers to distinguish between an end-of-file con‐
933 dition and terminal disconnect. POSIX.1‐2008 does not require implemen‐
934 tations to distinguish between the two situations, which permits his‐
935 torical implementations of the ed utility on historical platforms to
936 conform. Implementations are encouraged to distinguish between the two,
937 if possible, and take appropriate action on terminal disconnect.
938 Historically, ed accepted a zero address for the a and r commands in
940 order to insert text at the start of the edit buffer. When the buffer
941 was empty the command .= returned zero. POSIX.1‐2008 requires confor‐
942 mance to historical practice.
943 For consistency with the a and r commands and better user functional‐
945 ity, the i and c commands must also accept an address of 0, in which
946 case 0i is treated as 1i and likewise for the c command.
947 All of the following are valid addresses:
949 +++ Three lines after the current line.
951 /pattern/− One line before the next occurrence of pattern.
953 −2 Two lines before the current line.
955 3 −−−− 2 Line one (note the intermediate negative address).
957 1 2 3 Line six.
959 Any number of addresses can be provided to commands taking addresses;
961 for example, "1,2,3,4,5p" prints lines 4 and 5, because two is the
962 greatest valid number of addresses accepted by the print command. This,
963 in combination with the <semicolon> delimiter, permits users to create
964 commands based on ordered patterns in the file. For example, the com‐
965 mand "3;/foo/;+2p" will display the first line after line 3 that con‐
966 tains the pattern foo, plus the next two lines. Note that the address
967 "3;" must still be evaluated before being discarded, because the search
968 origin for the "/foo/" command depends on this.
969 Historically, ed disallowed address chains, as discussed above, con‐
971 sisting solely of <comma> or <semicolon> separators; for example, ",,,"
972 or ";;;" were considered an error. For consistency of address specifi‐
973 cation, this restriction is removed. The following table lists some of
974 the address forms now possible:
975 ┌────────┬───────┬───────┬────────────┬───────────────────────┐
977 │Address │ Addr1 │ Addr2 │ Status │ Comment │
978 ├────────┼───────┼───────┼────────────┼───────────────────────┤
979 │7, │ 7 │ 7 │ Historical │ │
980 │7,5, │ 5 │ 5 │ Historical │ │
981 │7,5,9 │ 5 │ 9 │ Historical │ │
982 │7,9 │ 7 │ 9 │ Historical │ │
983 │7,+ │ 7 │ 8 │ Historical │ │
984 │, │ 1 │ $ │ Historical │ │
985 │,7 │ 1 │ 7 │ Extension │ │
986 │,, │ $ │ $ │ Extension │ │
987 │,; │ $ │ $ │ Extension │ │
988 │7; │ 7 │ 7 │ Historical │ │
989 │7;5; │ 5 │ 5 │ Historical │ │
990 │7;5;9 │ 5 │ 9 │ Historical │ │
991 │7;5,9 │ 5 │ 9 │ Historical │ │
992 │7;$;4 │ $ │ 4 │ Historical │ Valid, but erroneous. │
993 │7;9 │ 7 │ 9 │ Historical │ │
994 │7;+ │ 7 │ 8 │ Historical │ │
995 │; │ . │ $ │ Historical │ │
996 │;7 │ . │ 7 │ Extension │ │
997 │;; │ $ │ $ │ Extension │ │
998 │;, │ $ │ $ │ Extension │ │
999 └────────┴───────┴───────┴────────────┴───────────────────────┘
1000 Historically, ed accepted the '^' character as an address, in which
1001 case it was identical to the <hyphen> character. POSIX.1‐2008 does not
1002 require or prohibit this behavior.
1003
1005 None.
1006
1008 Section 1.4, Utility Description Defaults, ex, sed, sh, vi
1009 The Base Definitions volume of POSIX.1‐2008, Table 5-1, Escape
1011 Sequences and Associated Actions, Chapter 8, Environment Variables,
1012 Section 9.3, Basic Regular Expressions, Chapter 11, General Terminal
1013 Interface, Section 12.2, Utility Syntax Guidelines
1014
1016 Portions of this text are reprinted and reproduced in electronic form
1017 from IEEE Std 1003.1, 2013 Edition, Standard for Information Technology
1018 -- Portable Operating System Interface (POSIX), The Open Group Base
1019 Specifications Issue 7, Copyright (C) 2013 by the Institute of Electri‐
1020 cal and Electronics Engineers, Inc and The Open Group. (This is
1021 POSIX.1-2008 with the 2013 Technical Corrigendum 1 applied.) In the
1022 event of any discrepancy between this version and the original IEEE and
1023 The Open Group Standard, the original IEEE and The Open Group Standard
1024 is the referee document. The original Standard can be obtained online
1025 at http://www.unix.org/online.html .
1026 Any typographical or formatting errors that appear in this page are
1028 most likely to have been introduced during the conversion of the source
1029 files to man page format. To report such errors, see https://www.ker‐
1030 nel.org/doc/man-pages/reporting_bugs.html .
1031IEEE/The Open Group 2013 ED(1P)