1ED(P) POSIX Programmer's Manual ED(P)
2
6 ed - edit text
7
9 ed [-p string][-s][file]
10
12 The ed utility is a line-oriented text editor that uses two modes: com‐
13 mand mode and input mode. In command mode the input characters shall be
14 interpreted as commands, and in input mode they shall be interpreted as
15 text. See the EXTENDED DESCRIPTION section.
16
18 The ed utility shall conform to the Base Definitions volume of
19 IEEE Std 1003.1-2001, Section 12.2, Utility Syntax Guidelines.
20 The following options shall be supported:
22 -p string
24 Use string as the prompt string when in command mode. By
25 default, there shall be no prompt string.
26 -s Suppress the writing of byte counts by e, E, r, and w commands
28 and of the '!' prompt after a !command.
29
32 The following operand shall be supported:
33 file If the file argument is given, ed shall simulate an e command on
35 the file named by the pathname, file, before accepting commands
36 from the standard input. If the file operand is '-' , the
37 results are unspecified.
38
41 The standard input shall be a text file consisting of commands, as
42 described in the EXTENDED DESCRIPTION section.
43
45 The input files shall be text files.
46
48 The following environment variables shall affect the execution of ed:
49 HOME Determine the pathname of the user's home directory.
51 LANG Provide a default value for the internationalization variables
53 that are unset or null. (See the Base Definitions volume of
54 IEEE Std 1003.1-2001, Section 8.2, Internationalization Vari‐
55 ables for the precedence of internationalization variables used
56 to determine the values of locale categories.)
57 LC_ALL If set to a non-empty string value, override the values of all
59 the other internationalization variables.
60 LC_COLLATE
62 Determine the locale for the behavior of ranges, equivalence
64 classes, and multi-character collating elements within regular
65 expressions.
66 LC_CTYPE
68 Determine the locale for the interpretation of sequences of
69 bytes of text data as characters (for example, single-byte as
70 opposed to multi-byte characters in arguments and input files)
71 and the behavior of character classes within regular expres‐
72 sions.
73 LC_MESSAGES
75 Determine the locale that should be used to affect the format
76 and contents of diagnostic messages written to standard error
77 and informative messages written to standard output.
78 NLSPATH
80 Determine the location of message catalogs for the processing of
81 LC_MESSAGES .
82
85 The ed utility shall take the standard action for all signals (see the
86 ASYNCHRONOUS EVENTS section in Utility Description Defaults ) with the
87 following exceptions:
88 SIGINT The ed utility shall interrupt its current activity, write the
90 string "?\n" to standard output, and return to command mode (see
91 the EXTENDED DESCRIPTION section).
92 SIGHUP If the buffer is not empty and has changed since the last write,
94 the ed utility shall attempt to write a copy of the buffer in a
95 file. First, the file named ed.hup in the current directory
96 shall be used; if that fails, the file named ed.hup in the
97 directory named by the HOME environment variable shall be used.
98 In any case, the ed utility shall exit without returning to com‐
99 mand mode.
100 SIGQUIT
102 The ed utility shall ignore this event.
103
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 not
135 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 IEEE Std 1003.1-2001, Section 9.3, Basic
140 Regular Expressions. Since regular expressions in ed are always matched
141 against single lines (excluding the terminating <newline>s), never
142 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 the
180 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 a
198 literal question mark instead of the BRE delimiter. If necessary,
199 the search shall wrap around to the end of the buffer and continue
200 up to and including the current line, so that the entire buffer is
201 searched.
202 7. A plus-sign ( '+' ) or hyphen character ( '-' ) followed by a deci‐
204 mal number shall address the current line plus or minus the number.
205 A plus-sign or hyphen character not followed by a decimal number
206 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 character followed by a decimal number shall
212 add or subtract, respectively, the indicated number of lines to or
213 from the address. A plus-sign or hyphen character not followed by a
214 decimal number shall add or subtract 1 to or from the address.
215 * A decimal number shall add the indicated number of lines to the
217 address.
218 It shall not be an error for an intermediate address value to be less
220 than zero or greater than the last line in the edit buffer. It shall be
221 an error for the final address value to be less than zero or greater
222 than the last line in the edit buffer. It shall be an error if a search
223 for a BRE fails to find a matching line.
224 Commands accept zero, one, or two addresses. If more than the required
226 number of addresses are provided to a command that requires zero
227 addresses, it shall be an error. Otherwise, if more than the required
228 number of addresses are provided to a command, the addresses specified
229 first shall be evaluated and then discarded until the maximum number of
230 valid addresses remain, for the specified command.
231 Addresses shall be separated from each other by a comma ( ',' ) or
233 semicolon character ( ';' ). In the case of a semicolon separator, the
234 current line ( '.' ) shall be set to the first address, and only then
235 will the second address be calculated. This feature can be used to
236 determine the starting line for forwards and backwards searches; see
237 rules 5. and 6.
238 Addresses can be omitted on either side of the comma or semicolon sepa‐
240 rator, in which case the resulting address pairs shall be as follows:
241 Specified Resulting
243 , 1 , $
244 , addr 1 , addr
245 addr , addr , addr
246 ; . ; $
247 ; addr . ; addr
248 addr ; addr ; addr
249 Any <blank>s included between addresses, address separators, or address
251 offsets shall be ignored.
252 Commands in ed
254 In the following list of ed commands, the default addresses are shown
255 in parentheses. The number of addresses shown in the default shall be
256 the number expected by the command. The parentheses are not part of the
257 address; they show that the given addresses are the default.
258 It is generally invalid for more than one command to appear on a line.
260 However, any command (except e, E, f, q, Q, r, w, and !) can be suf‐
261 fixed by the letter l, n, or p; in which case, except for the l, n, and
262 p commands, the command shall be executed and then the new current line
263 shall be written as described below under the l, n, and p commands.
264 When an l, n, or p suffix is used with an l, n, or p command, the com‐
265 mand shall write to standard output as described below, but it is
266 unspecified whether the suffix writes the current line again in the
267 requested format or whether the suffix has no effect. For example, the
268 pl command (base p command with an l suffix) shall either write just
269 the current line or write it twice-once as specified for p and once as
270 specified for l. Also, the g, G, v, and V commands shall take a com‐
271 mand as a parameter.
272 Each address component can be preceded by zero or more <blank>s. The
274 command letter can be preceded by zero or more <blank>s. If a suffix
275 letter ( l, n, or p) is given, the application shall ensure that it
276 immediately follows the command.
277 The e, E, f, r, and w commands shall take an optional file parameter,
279 separated from the command letter by one or more <blank>s.
280 If changes have been made in the buffer since the last w command that
282 wrote the entire buffer, ed shall warn the user if an attempt is made
283 to destroy the editor buffer via the e or q commands. The ed utility
284 shall write the string:
285 "?\n"
288 (followed by an explanatory message if help mode has been enabled via
290 the H command) to standard output and shall continue in command mode
291 with the current line number unchanged. If the e or q command is
292 repeated with no intervening command, it shall take effect.
293 If a terminal disconnect is detected:
295 * If the buffer is not empty and has changed since the last write, the
297 ed utility shall attempt to write a copy of the buffer to a file
298 named ed.hup in the current directory. If this write fails, ed shall
299 attempt to write a copy of the buffer to a filename ed.hup in the
300 directory named by the HOME environment variable. If both these
301 attempts fail, ed shall exit without saving the buffer.
302 * The ed utility shall not write the file to the currently remembered
304 pathname or return to command mode, and shall terminate with a non-
305 zero exit status.
306 If an end-of-file is detected on standard input:
308 * If the ed utility is in input mode, ed shall terminate input mode
310 and return to command mode. It is unspecified if any partially
311 entered lines (that is, input text without a terminating <newline>)
312 are discarded from the input text.
313 * If the ed utility is in command mode, it shall act as if a q command
315 had been entered.
316 If the closing delimiter of an RE or of a replacement string (for exam‐
318 ple, '/' ) in a g, G, s, v, or V command would be the last character
319 before a <newline>, that delimiter can be omitted, in which case the
320 addressed line shall be written. For example, the following pairs of
321 commands are equivalent:
322 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"
332 (followed by an explanatory message if help mode has been enabled via
334 the H command) to standard output and shall continue in command mode
335 with the current line number unchanged.
336 Append Command
338 Synopsis:
339 (.)a
342 <text>
343 .
344 The a command shall read the given text and append it after the
347 addressed line; the current line number shall become the address of the
348 last inserted line or, if there were none, the addressed line. Address
349 0 shall be valid for this command; it shall cause the appended text to
350 be placed at the beginning of the buffer.
351 Change Command
353 Synopsis:
354 (.,.)c
357 <text>
358 .
359 The c command shall delete the addressed lines, then accept input text
362 that replaces these lines; the current line shall be set to the address
363 of the last line input; or, if there were none, at the line after the
364 last line deleted; if the lines deleted were originally at the end of
365 the buffer, the current line number shall be set to the address of the
366 new last line; if no lines remain in the buffer, the current line num‐
367 ber shall be set to zero. Address 0 shall be valid for this command;
368 it shall be interpreted as if address 1 were specified.
369 Delete Command
371 Synopsis:
372 (.,.)d
375 The d command shall delete the addressed lines from the buffer. The
378 address of the line after the last line deleted shall become the cur‐
379 rent line number; if the lines deleted were originally at the end of
380 the buffer, the current line number shall be set to the address of the
381 new last line; if no lines remain in the buffer, the current line num‐
382 ber shall be set to zero.
383 Edit Command
385 Synopsis:
386 e [file]
389 The e command shall delete the entire contents of the buffer and then
392 read in the file named by the pathname file. The current line number
393 shall be set to the address of the last line of the buffer. If no path‐
394 name is given, the currently remembered pathname, if any, shall be used
395 (see the f command). The number of bytes read shall be written to
396 standard output, unless the -s option was specified, in the following
397 format:
398 "%d\n", <number of bytes read>
401 The name file shall be remembered for possible use as a default path‐
403 name in subsequent e, E, r, and w commands. If file is replaced by '!'
404 , the rest of the line shall be taken to be a shell command line whose
405 output is to be read. Such a shell command line shall not be remembered
406 as the current file. All marks shall be discarded upon the completion
407 of a successful e command. If the buffer has changed since the last
408 time the entire buffer was written, the user shall be warned, as
409 described previously.
410 Edit Without Checking Command
412 Synopsis:
413 E [file]
416 The E command shall possess all properties and restrictions of the e
419 command except that the editor shall not check to see whether any
420 changes have been made to the buffer since the last w command.
421 Filename Command
423 Synopsis:
424 f [file]
427 If file is given, the f command shall change the currently remembered
430 pathname to file; whether the name is changed or not, it shall then
431 write the (possibly new) currently remembered pathname to the standard
432 output in the following format:
433 "%s\n", <pathname>
436 The current line number shall be unchanged.
438 Global Command
440 Synopsis:
441 (1,$)g/RE/command list
444 In the g command, the first step shall be to mark every line for which
447 the line excluding the terminating <newline> matches the given RE.
448 Then, going sequentially from the beginning of the file to the end of
449 the file, the given command list shall be executed for each marked
450 line, with the current line number set to the address of that line. Any
451 line modified by the command list shall be unmarked. When the g command
452 completes, the current line number shall have the value assigned by the
453 last command in the command list. If there were no matching lines, the
454 current line number shall not be changed. A single command or the first
455 of a list of commands shall appear on the same line as the global com‐
456 mand. All lines of a multi-line list except the last line shall be
457 ended with a backslash preceding the terminating <newline>; the a, i,
458 and c commands and associated input are permitted. The '.' terminating
459 input mode can be omitted if it would be the last line of the command
460 list. An empty command list shall be equivalent to the p command. The
461 use of the g, G, v, V, and ! commands in the command list produces
462 undefined results. Any character other than <space> or <newline> can be
463 used instead of a slash to delimit the RE. Within the RE, the RE delim‐
464 iter itself can be used as a literal character if it is preceded by a
465 backslash.
466 Interactive Global Command
468 Synopsis:
469 (1,$)G/RE/
472 In the G command, the first step shall be to mark every line for which
475 the line excluding the terminating <newline> matches the given RE.
476 Then, for every such line, that line shall be written, the current line
477 number shall be set to the address of that line, and any one command
478 (other than one of the a, c, i, g, G, v, and V commands) shall be read
479 and executed. A <newline> shall act as a null command (causing no
480 action to be taken on the current line); an '&' shall cause the re-exe‐
481 cution of the most recent non-null command executed within the current
482 invocation of G. Note that the commands input as part of the execution
483 of the G command can address and affect any lines in the buffer. Any
484 line modified by the command shall be unmarked. The final value of the
485 current line number shall be the value set by the last command success‐
486 fully executed. (Note that the last command successfully executed shall
487 be the G command itself if a command fails or the null command is spec‐
488 ified.) If there were no matching lines, the current line number shall
489 not be changed. The G command can be terminated by a SIGINT signal. Any
490 character other than <space> or <newline> can be used instead of a
491 slash to delimit the RE and the replacement. Within the RE, the RE
492 delimiter itself can be used as a literal character if it is preceded
493 by a backslash.
494 Help Command
496 Synopsis:
497 h
500 The h command shall write a short message to standard output that
503 explains the reason for the most recent '?' notification. The current
504 line number shall be unchanged.
505 Help-Mode Command
507 Synopsis:
508 H
511 The H command shall cause ed to enter a mode in which help messages
514 (see the h command) shall be written to standard output for all subse‐
515 quent '?' notifications. The H command alternately shall turn this mode
516 on and off; it is initially off. If the help-mode is being turned on,
517 the H command also explains the previous '?' notification, if there was
518 one. The current line number shall be unchanged.
519 Insert Command
521 Synopsis:
522 (.)i
525 <text>
526 .
527 The i command shall insert the given text before the addressed line;
530 the current line is set to the last inserted line or, if there was
531 none, to the addressed line. This command differs from the a command
532 only in the placement of the input text. Address 0 shall be valid for
533 this command; it shall be interpreted as if address 1 were specified.
534 Join Command
536 Synopsis:
537 (.,.+1)j
540 The j command shall join contiguous lines by removing the appropriate
543 <newline>s. If exactly one address is given, this command shall do
544 nothing. If lines are joined, the current line number shall be set to
545 the address of the joined line; otherwise, the current line number
546 shall be unchanged.
547 Mark Command
549 Synopsis:
550 (.)kx
553 The k command shall mark the addressed line with name x, which the
556 application shall ensure is a lowercase letter from the portable char‐
557 acter set. The address "'x" shall then refer to this line; the current
558 line number shall be unchanged.
559 List Command
561 Synopsis:
562 (.,.)l
565 The l command shall write to standard output the addressed lines in a
568 visually unambiguous form. The characters listed in the Base Defini‐
569 tions volume of IEEE Std 1003.1-2001, Table 5-1, Escape Sequences and
570 Associated Actions ( '\\' , '\a' , '\b' , '\f' , '\r' , '\t' , '\v' )
571 shall be written as the corresponding escape sequence; the '\n' in that
572 table is not applicable. Non-printable characters not in the table
573 shall be written as one three-digit octal number (with a preceding
574 backslash character) for each byte in the character (most significant
575 byte first). If the size of a byte on the system is greater than nine
576 bits, the format used for non-printable characters is implementation-
577 defined.
578 Long lines shall be folded, with the point of folding indicated by
580 <newline> preceded by a backslash; the length at which folding occurs
581 is unspecified, but should be appropriate for the output device. The
582 end of each line shall be marked with a '$' , and '$' characters within
583 the text shall be written with a preceding backslash. An l command can
584 be appended to any other command other than e, E, f, q, Q, r, w, or !.
585 The current line number shall be set to the address of the last line
586 written.
587 Move Command
589 Synopsis:
590 (.,.)maddress
593 The m command shall reposition the addressed lines after the line
596 addressed by address. Address 0 shall be valid for address and cause
597 the addressed lines to be moved to the beginning of the buffer. It
598 shall be an error if address address falls within the range of moved
599 lines. The current line number shall be set to the address of the last
600 line moved.
601 Number Command
603 Synopsis:
604 (.,.)n
607 The n command shall write to standard output the addressed lines, pre‐
610 ceding each line by its line number and a <tab>; the current line num‐
611 ber shall be set to the address of the last line written. The n command
612 can be appended to any command other than e, E, f, q, Q, r, w, or !.
613 Print Command
615 Synopsis:
616 (.,.)p
619 The p command shall write to standard output the addressed lines; the
622 current line number shall be set to the address of the last line writ‐
623 ten. The p command can be appended to any command other than e, E, f,
624 q, Q, r, w, or !.
625 Prompt Command
627 Synopsis:
628 P
631 The P command shall cause ed to prompt with an asterisk ( '*' ) (or
634 string, if -p is specified) for all subsequent commands. The P command
635 alternatively shall turn this mode on and off; it shall be initially on
636 if the -p option is specified; otherwise, off. The current line number
637 shall be unchanged.
638 Quit Command
640 Synopsis:
641 q
644 The q command shall cause ed to exit. If the buffer has changed since
647 the last time the entire buffer was written, the user shall be warned,
648 as described previously.
649 Quit Without Checking Command
651 Synopsis:
652 Q
655 The Q command shall cause ed to exit without checking whether changes
658 have been made in the buffer since the last w command.
659 Read Command
661 Synopsis:
662 ($)r [file]
665 The r command shall read in the file named by the pathname file and
668 append it after the addressed line. If no file argument is given, the
669 currently remembered pathname, if any, shall be used (see the e and f
670 commands). The currently remembered pathname shall not be changed
671 unless there is no remembered pathname. Address 0 shall be valid for r
672 and shall cause the file to be read at the beginning of the buffer. If
673 the read is successful, and -s was not specified, the number of bytes
674 read shall be written to standard output in the following format:
675 "%d\n", <number of bytes read>
678 The current line number shall be set to the address of the last line
680 read in. If file is replaced by '!' , the rest of the line shall be
681 taken to be a shell command line whose output is to be read. Such a
682 shell command line shall not be remembered as the current pathname.
683 Substitute Command
685 Synopsis:
686 (.,.)s/RE/replacement/flags
689 The s command shall search each addressed line for an occurrence of the
692 specified RE and replace either the first or all (non-overlapped)
693 matched strings with the replacement; see the following description of
694 the g suffix. It is an error if the substitution fails on every
695 addressed line. Any character other than <space> or <newline> can be
696 used instead of a slash to delimit the RE and the replacement. Within
697 the RE, the RE delimiter itself can be used as a literal character if
698 it is preceded by a backslash. The current line shall be set to the
699 address of the last line on which a substitution occurred.
700 An ampersand ( '&' ) appearing in the replacement shall be replaced by
702 the string matching the RE on the current line. The special meaning of
703 '&' in this context can be suppressed by preceding it by backslash. As
704 a more general feature, the characters '\n' , where n is a digit, shall
705 be replaced by the text matched by the corresponding back-reference
706 expression. When the character '%' is the only character in the
707 replacement, the replacement used in the most recent substitute command
708 shall be used as the replacement in the current substitute command; if
709 there was no previous substitute command, the use of '%' in this manner
710 shall be an error. The '%' shall lose its special meaning when it is in
711 a replacement string of more than one character or is preceded by a
712 backslash. For each backslash ( '\' ) encountered in scanning replace‐
713 ment from beginning to end, the following character shall lose its spe‐
714 cial meaning (if any). It is unspecified what special meaning is given
715 to any character other than '&' , '\' , '%' , or digits.
716 A line can be split by substituting a <newline> into it. The applica‐
718 tion shall ensure it escapes the <newline> in the replacement by pre‐
719 ceding it by backslash. Such substitution cannot be done as part of a g
720 or v command list. The current line number shall be set to the address
721 of the last line on which a substitution is performed. If no substitu‐
722 tion is performed, the current line number shall be unchanged. If a
723 line is split, a substitution shall be considered to have been per‐
724 formed on each of the new lines for the purpose of determining the new
725 current line number. A substitution shall be considered to have been
726 performed even if the replacement string is identical to the string
727 that it replaces.
728 The application shall ensure that the value of flags is zero or more
730 of:
731 count Substitute for the countth occurrence only of the RE found on
733 each addressed line.
734 g Globally substitute for all non-overlapping instances of the RE
736 rather than just the first one. If both g and count are speci‐
737 fied, the results are unspecified.
738 l Write to standard output the final line in which a substitution
740 was made. The line shall be written in the format specified for
741 the l command.
742 n Write to standard output the final line in which a substitution
744 was made. The line shall be written in the format specified for
745 the n command.
746 p Write to standard output the final line in which a substitution
748 was made. The line shall be written in the format specified for
749 the p command.
750 Copy Command
753 Synopsis:
754 (.,.)taddress
757 The t command shall be equivalent to the m command, except that a copy
760 of the addressed lines shall be placed after address address (which can
761 be 0); the current line number shall be set to the address of the last
762 line added.
763 Undo Command
765 Synopsis:
766 u
769 The u command shall nullify the effect of the most recent command that
772 modified anything in the buffer, namely the most recent a, c, d, g, i,
773 j, m, r, s, t, u, v, G, or V command. All changes made to the buffer by
774 a g, G, v, or V global command shall be undone as a single change; if
775 no changes were made by the global command (such as with g/RE/ p), the
776 u command shall have no effect. The current line number shall be set to
777 the value it had immediately before the command being undone started.
778 Global Non-Matched Command
780 Synopsis:
781 (1,$)v/RE/command list
784 This command shall be equivalent to the global command g except that
787 the lines that are marked during the first step shall be those for
788 which the line excluding the terminating <newline> does not match the
789 RE.
790 Interactive Global Not-Matched Command
792 Synopsis:
793 (1,$)V/RE/
796 This command shall be equivalent to the interactive global command G
799 except that the lines that are marked during the first step shall be
800 those for which the line excluding the terminating <newline> does not
801 match the RE.
802 Write Command
804 Synopsis:
805 (1,$)w [file]
808 The w command shall write the addressed lines into the file named by
811 the pathname file. The command shall create the file, if it does not
812 exist, or shall replace the contents of the existing file. The cur‐
813 rently remembered pathname shall not be changed unless there is no
814 remembered pathname. If no pathname is given, the currently remembered
815 pathname, if any, shall be used (see the e and f commands); the current
816 line number shall be unchanged. If the command is successful, the num‐
817 ber of bytes written shall be written to standard output, unless the -s
818 option was specified, in the following format:
819 "%d\n", <number of bytes written>
822 If file begins with '!' , the rest of the line shall be taken to be a
824 shell command line whose standard input shall be the addressed lines.
825 Such a shell command line shall not be remembered as the current path‐
826 name. This usage of the write command with '!' shall not be considered
827 as a "last w command that wrote the entire buffer", as described previ‐
828 ously; thus, this alone shall not prevent the warning to the user if an
829 attempt is made to destroy the editor buffer via the e or q commands.
830 Line Number Command
832 Synopsis:
833 ($)=
836 The line number of the addressed line shall be written to standard out‐
839 put in the following format:
840 "%d\n", <line number>
843 The current line number shall be unchanged by this command.
845 Shell Escape Command
847 Synopsis:
848 !command
851 The remainder of the line after the '!' shall be sent to the command
854 interpreter to be interpreted as a shell command line. Within the text
855 of that shell command line, the unescaped character '%' shall be
856 replaced with the remembered pathname; if a '!' appears as the first
857 character of the command, it shall be replaced with the text of the
858 previous shell command executed via '!' . Thus, "!!" shall repeat the
859 previous !command. If any replacements of '%' or '!' are performed, the
860 modified line shall be written to the standard output before command is
861 executed. The ! command shall write:
862 "!\n"
865 to standard output upon completion, unless the -s option is specified.
867 The current line number shall be unchanged.
868 Null Command
870 Synopsis:
871 (.+1)
874 An address alone on a line shall cause the addressed line to be writ‐
877 ten. A <newline> alone shall be equivalent to "+1p" . The current line
878 number shall be set to the address of the written line.
879
881 The following exit values shall be returned:
882 0 Successful completion without any file or command errors.
884 >0 An error occurred.
886
889 When an error in the input script is encountered, or when an error is
890 detected that is a consequence of the data (not) present in the file or
891 due to an external condition such as a read or write error:
892 * If the standard input is a terminal device file, all input shall be
894 flushed, and a new command read.
895 * If the standard input is a regular file, ed shall terminate with a
897 non-zero exit status.
898 The following sections are informative.
900
902 Because of the extremely terse nature of the default error messages,
903 the prudent script writer begins the ed input commands with an H com‐
904 mand, so that if any errors do occur at least some clue as to the cause
905 is made available.
906 In previous versions, an obsolescent - option was described. This is
908 no longer specified. Applications should use the -s option. Using - as
909 a file operand now produces unspecified results. This allows implemen‐
910 tations to continue to support the former required behavior.
911
913 None.
914
916 The initial description of this utility was adapted from the SVID. It
917 contains some features not found in Version 7 or BSD-derived systems.
918 Some of the differences between the POSIX and BSD ed utilities include,
919 but need not be limited to:
920 * The BSD - option does not suppress the '!' prompt after a ! command.
922 * BSD does not support the special meanings of the '%' and '!' char‐
924 acters within a ! command.
925 * BSD does not support the addresses ';' and ',' .
927 * BSD allows the command/suffix pairs pp, ll, and so on, which are
929 unspecified in this volume of IEEE Std 1003.1-2001.
930 * BSD does not support the '!' character part of the e, r, or w com‐
932 mands.
933 * A failed g command in BSD sets the line number to the last line
935 searched if there are no matches.
936 * BSD does not default the command list to the p command.
938 * BSD does not support the G, h, H, n, or V commands.
940 * On BSD, if there is no inserted text, the insert command changes the
942 current line to the referenced line -1; that is, the line before the
943 specified line.
944 * On BSD, the join command with only a single address changes the cur‐
946 rent line to that address.
947 * BSD does not support the P command; moreover, in BSD it is synony‐
949 mous with the p command.
950 * BSD does not support the undo of the commands j, m, r, s, or t.
952 * The Version 7 ed command W, and the BSD ed commands W, wq, and z are
954 not present in this volume of IEEE Std 1003.1-2001.
955 The -s option was added to allow the functionality of the now withdrawn
957 - option in a manner compatible with the Utility Syntax Guidelines.
958 In early proposals there was a limit, {ED_FILE_MAX}, that described the
960 historical limitations of some ed utilities in their handling of large
961 files; some of these have had problems with files larger than 100000
962 bytes. It was this limitation that prompted much of the desire to
963 include a split command in this volume of IEEE Std 1003.1-2001. Since
964 this limit was removed, this volume of IEEE Std 1003.1-2001 requires
965 that implementations document the file size limits imposed by ed in the
966 conformance document. The limit {ED_LINE_MAX} was also removed; there‐
967 fore, the global limit {LINE_MAX} is used for input and output lines.
968 The manner in which the l command writes non-printable characters was
970 changed to avoid the historical backspace-overstrike method. On video
971 display terminals, the overstrike is ambiguous because most terminals
972 simply replace overstruck characters, making the l format not useful
973 for its intended purpose of unambiguously understanding the content of
974 the line. The historical backslash escapes were also ambiguous. (The
975 string "a\0011" could represent a line containing those six characters
976 or a line containing the three characters 'a' , a byte with a binary
977 value of 1, and a 1.) In the format required here, a backslash appear‐
978 ing in the line is written as "\\" so that the output is truly unam‐
979 biguous. The method of marking the ends of lines was adopted from the
980 ex editor and is required for any line ending in <space>s; the '$' is
981 placed on all lines so that a real '$' at the end of a line cannot be
982 misinterpreted.
983 Systems with bytes too large to fit into three octal digits must devise
985 other means of displaying non-printable characters. Consideration was
986 given to requiring that the number of octal digits be large enough to
987 hold a byte, but this seemed to be too confusing for applications on
988 the vast majority of systems where three digits are adequate. It would
989 be theoretically possible for the application to use the getconf util‐
990 ity to find out the CHAR_BIT value and deal with such an algorithm;
991 however, there is really no portable way that an application can use
992 the octal values of the bytes across various coded character sets, so
993 the additional specification was not worthwhile.
994 The description of how a NUL is written was removed. The NUL character
996 cannot be in text files, and this volume of IEEE Std 1003.1-2001 should
997 not dictate behavior in the case of undefined, erroneous input.
998 Unlike some of the other editing utilities, the filenames accepted by
1000 the E, e, R, and r commands are not patterns.
1001 Early proposals stated that the -p option worked only when standard
1003 input was associated with a terminal device. This has been changed to
1004 conform to historical implementations, thereby allowing applications to
1005 interpose themselves between a user and the ed utility.
1006 The form of the substitute command that uses the n suffix was limited
1008 in some historical documentation (where this was described incorrectly
1009 as "backreferencing"). This limit has been omitted because there is no
1010 reason why an editor processing lines of {LINE_MAX} length should have
1011 this restriction. The command s/x/X/2047 should be able to substitute
1012 the 2047th occurrence of 'x' on a line.
1013 The use of printing commands with printing suffixes (such as pn, lp,
1015 and so on) was made unspecified because BSD-based systems allow this,
1016 whereas System V does not.
1017 Some BSD-based systems exit immediately upon receipt of end-of-file if
1019 all of the lines in the file have been deleted. Since this volume of
1020 IEEE Std 1003.1-2001 refers to the q command in this instance, such
1021 behavior is not allowed.
1022 Some historical implementations returned exit status zero even if com‐
1024 mand errors had occurred; this is not allowed by this volume of
1025 IEEE Std 1003.1-2001.
1026 Some historical implementations contained a bug that allowed a single
1028 period to be entered in input mode as <backslash> <period> <newline>.
1029 This is not allowed by ed because there is no description of escaping
1030 any of the characters in input mode; backslashes are entered into the
1031 buffer exactly as typed. The typical method of entering a single period
1032 has been to precede it with another character and then use the substi‐
1033 tute command to delete that character.
1034 It is difficult under some modes of some versions of historical operat‐
1036 ing system terminal drivers to distinguish between an end-of-file con‐
1037 dition and terminal disconnect. IEEE Std 1003.1-2001 does not require
1038 implementations to distinguish between the two situations, which per‐
1039 mits historical implementations of the ed utility on historical plat‐
1040 forms to conform. Implementations are encouraged to distinguish
1041 between the two, if possible, and take appropriate action on terminal
1042 disconnect.
1043 Historically, ed accepted a zero address for the a and r commands in
1045 order to insert text at the start of the edit buffer. When the buffer
1046 was empty the command .= returned zero. IEEE Std 1003.1-2001 requires
1047 conformance to historical practice.
1048 For consistency with the a and r commands and better user functional‐
1050 ity, the i and c commands must also accept an address of 0, in which
1051 case 0i is treated as 1i and likewise for the c command.
1052 All of the following are valid addresses:
1054 +++ Three lines after the current line.
1056 /pattern/-
1058 One line before the next occurrence of pattern.
1059 -2 Two lines before the current line.
1061 3 ---- 2
1063 Line one (note the intermediate negative address).
1064 1 2 3 Line six.
1066 Any number of addresses can be provided to commands taking addresses;
1069 for example, "1,2,3,4,5p" prints lines 4 and 5, because two is the
1070 greatest valid number of addresses accepted by the print command. This,
1071 in combination with the semicolon delimiter, permits users to create
1072 commands based on ordered patterns in the file. For example, the com‐
1073 mand "3;/foo/;+2p" will display the first line after line 3 that con‐
1074 tains the pattern foo, plus the next two lines. Note that the address
1075 "3;" must still be evaluated before being discarded, because the search
1076 origin for the "/foo/" command depends on this.
1077 Historically, ed disallowed address chains, as discussed above, con‐
1079 sisting solely of comma or semicolon separators; for example, ",,," or
1080 ";;;" were considered an error. For consistency of address specifica‐
1081 tion, this restriction is removed. The following table lists some of
1082 the address forms now possible:
1083 Address Addr1 Addr2 Status Comment
1085 7, 7 7 Historical
1086 7,5, 5 5 Historical
1087 7,5,9 5 9 Historical
1088 7,9 7 9 Historical
1089 7,+ 7 8 Historical
1090 , 1 $ Historical
1091 ,7 1 7 Extension
1092 ,, $ $ Extension
1093 ,; $ $ Extension
1094 7; 7 7 Historical
1095 7;5; 5 5 Historical
1096 7;5;9 5 9 Historical
1097 7;5,9 5 9 Historical
1098 7;$;4 $ 4 Historical Valid, but erroneous.
1100 7;9 7 9 Historical
1101 7;+ 7 8 Historical
1102 ; . $ Historical
1103 ;7 . 7 Extension
1104 ;; $ $ Extension
1105 ;, $ $ Extension
1106 Historically, values could be added to addresses by including them
1108 after one or more <blank>s; for example, "3 - 5p" wrote the seventh
1109 line of the file, and "/foo/ 5" was the same as "5 /foo/" . However,
1110 only absolute values could be added; for example, "5 /foo/" was an
1111 error. IEEE Std 1003.1-2001 requires conformance to historical prac‐
1112 tice.
1113 Historically, ed accepted the '^' character as an address, in which
1115 case it was identical to the hyphen character. IEEE Std 1003.1-2001
1116 does not require or prohibit this behavior.
1117
1119 None.
1120
1122 Utility Description Defaults , ex , sed , sh , vi
1123
1125 Portions of this text are reprinted and reproduced in electronic form
1126 from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
1127 -- Portable Operating System Interface (POSIX), The Open Group Base
1128 Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of
1129 Electrical and Electronics Engineers, Inc and The Open Group. In the
1130 event of any discrepancy between this version and the original IEEE and
1131 The Open Group Standard, the original IEEE and The Open Group Standard
1132 is the referee document. The original Standard can be obtained online
1133 at http://www.opengroup.org/unix/online.html .
1134IEEE/The Open Group 2003 ED(P)