1.\" Copyright (c) 1992, 1993 2.\" The Regents of the University of California. All rights reserved. 3.\" 4.\" This code is derived from software contributed to Berkeley by 5.\" the Institute of Electrical and Electronics Engineers, Inc. 6.\" 7.\" Redistribution and use in source and binary forms, with or without 8.\" modification, are permitted provided that the following conditions 9.\" are met: 10.\" 1. Redistributions of source code must retain the above copyright 11.\" notice, this list of conditions and the following disclaimer. 12.\" 2. Redistributions in binary form must reproduce the above copyright 13.\" notice, this list of conditions and the following disclaimer in the 14.\" documentation and/or other materials provided with the distribution. 15.\" 3. All advertising materials mentioning features or use of this software 16.\" must display the following acknowledgement: 17.\" This product includes software developed by the University of 18.\" California, Berkeley and its contributors. 19.\" 4. Neither the name of the University nor the names of its contributors 20.\" may be used to endorse or promote products derived from this software 21.\" without specific prior written permission. 22.\" 23.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33.\" SUCH DAMAGE. 34.\" 35.\" @(#)sed.1 8.2 (Berkeley) 12/30/93 36.\" $FreeBSD$ 37.\" 38.Dd May 7, 2002 39.Dt SED 1 40.Os 41.Sh NAME 42.Nm sed 43.Nd stream editor 44.Sh SYNOPSIS 45.Nm 46.Op Fl Ean 47.Ar command 48.Op Ar 49.Nm 50.Op Fl Ean 51.Op Fl e Ar command 52.Op Fl f Ar command_file 53.Op Fl i Ar extension 54.Op Ar 55.Sh DESCRIPTION 56The 57.Nm 58utility reads the specified files, or the standard input if no files 59are specified, modifying the input as specified by a list of commands. 60The input is then written to the standard output. 61.Pp 62A single command may be specified as the first argument to 63.Nm . 64Multiple commands may be specified by using the 65.Fl e 66or 67.Fl f 68options. 69All commands are applied to the input in the order they are specified 70regardless of their origin. 71.Pp 72The following options are available: 73.Bl -tag -width indent 74.It Fl E 75Interpret regular expressions as extended (modern) regular expressions 76rather than basic regular expressions (BRE's). 77The 78.Xr re_format 7 79manual page fully describes both formats. 80.It Fl a 81The files listed as parameters for the 82.Dq w 83functions are created (or truncated) before any processing begins, 84by default. 85The 86.Fl a 87option causes 88.Nm 89to delay opening each file until a command containing the related 90.Dq w 91function is applied to a line of input. 92.It Fl e Ar command 93Append the editing commands specified by the 94.Ar command 95argument 96to the list of commands. 97.It Fl f Ar command_file 98Append the editing commands found in the file 99.Ar command_file 100to the list of commands. 101The editing commands should each be listed on a separate line. 102.It Fl i Ar extension 103Edit files in-place, saving backups with the specified 104.Ar extension . 105If a zero-length 106.Ar extension 107is given, no backup will be saved. 108It is not recommended to give a zero-length 109.Ar extension 110when in-place editing files, as you risk corruption or partial content 111in situations where disk space is exhausted, etc. 112.It Fl n 113By default, each line of input is echoed to the standard output after 114all of the commands have been applied to it. 115The 116.Fl n 117option suppresses this behavior. 118.El 119.Pp 120The form of a 121.Nm 122command is as follows: 123.Pp 124.Dl [address[,address]]function[arguments] 125.Pp 126Whitespace may be inserted before the first address and the function 127portions of the command. 128.Pp 129Normally, 130.Nm 131cyclically copies a line of input, not including its terminating newline 132character, into a 133.Em "pattern space" , 134(unless there is something left after a 135.Dq D 136function), 137applies all of the commands with addresses that select that pattern space, 138copies the pattern space to the standard output, appending a newline, and 139deletes the pattern space. 140.Pp 141Some of the functions use a 142.Em "hold space" 143to save all or part of the pattern space for subsequent retrieval. 144.Sh "Sed Addresses" 145An address is not required, but if specified must be a number (that counts 146input lines 147cumulatively across input files), a dollar 148.Pq Dq $ 149character that addresses the last line of input, or a context address 150(which consists of a regular expression preceded and followed by a 151delimiter). 152.Pp 153A command line with no addresses selects every pattern space. 154.Pp 155A command line with one address selects all of the pattern spaces 156that match the address. 157.Pp 158A command line with two addresses selects an inclusive range. This 159range starts with the first pattern space that matches the first 160address. The end of the range is the next following pattern space 161that matches the second address. If the second address is a number 162less than or equal to the line number first selected, only that 163line is selected. In the case when the second address is a context 164address, sed does not re-match the second address against the 165pattern space that matched the first address. Starting at the 166first line following the selected range, 167.Nm 168starts looking again for the first address. 169.Pp 170Editing commands can be applied to non-selected pattern spaces by use 171of the exclamation character 172.Pq Dq \&! 173function. 174.Sh "Sed Regular Expressions" 175The regular expressions used in 176.Nm , 177by default, are basic regular expressions (BREs, see 178.Xr re_format 7 179for more information). 180.Nm 181can use extended (modern) regular expressions instead if the 182.Fl E 183flag is given. 184In addition, 185.Nm 186has the following two additions to regular expressions: 187.Pp 188.Bl -enum -compact 189.It 190In a context address, any character other than a backslash 191.Pq Dq \e 192or newline character may be used to delimit the regular expression. 193Also, putting a backslash character before the delimiting character 194causes the character to be treated literally. 195For example, in the context address \exabc\exdefx, the RE delimiter 196is an 197.Dq x 198and the second 199.Dq x 200stands for itself, so that the regular expression is 201.Dq abcxdef . 202.Pp 203.It 204The escape sequence \en matches a newline character embedded in the 205pattern space. 206You can't, however, use a literal newline character in an address or 207in the substitute command. 208.El 209.Pp 210One special feature of 211.Nm 212regular expressions is that they can default to the last regular 213expression used. 214If a regular expression is empty, i.e. just the delimiter characters 215are specified, the last regular expression encountered is used instead. 216The last regular expression is defined as the last regular expression 217used as part of an address or substitute command, and at run-time, not 218compile-time. 219For example, the command 220.Dq /abc/s//XXX/ 221will substitute 222.Dq XXX 223for the pattern 224.Dq abc . 225.Sh "Sed Functions" 226In the following list of commands, the maximum number of permissible 227addresses for each command is indicated by [0addr], [1addr], or [2addr], 228representing zero, one, or two addresses. 229.Pp 230The argument 231.Em text 232consists of one or more lines. 233To embed a newline in the text, precede it with a backslash. 234Other backslashes in text are deleted and the following character 235taken literally. 236.Pp 237The 238.Dq r 239and 240.Dq w 241functions take an optional file parameter, which should be separated 242from the function letter by white space. 243Each file given as an argument to 244.Nm 245is created (or its contents truncated) before any input processing begins. 246.Pp 247The 248.Dq b , 249.Dq r , 250.Dq s , 251.Dq t , 252.Dq w , 253.Dq y , 254.Dq \&! , 255and 256.Dq \&: 257functions all accept additional arguments. 258The following synopses indicate which arguments have to be separated from 259the function letters by white space characters. 260.Pp 261Two of the functions take a function-list. 262This is a list of 263.Nm 264functions separated by newlines, as follows: 265.Bd -literal -offset indent 266{ function 267 function 268 ... 269 function 270} 271.Ed 272.Pp 273The 274.Dq { 275can be preceded by white space and can be followed by white space. 276The function can be preceded by white space. 277The terminating 278.Dq } 279must be preceded by a newline or optional white space. 280.Pp 281.Bl -tag -width "XXXXXX" -compact 282.It [2addr] function-list 283Execute function-list only when the pattern space is selected. 284.Pp 285.It [1addr]a\e 286.It text 287Write 288.Em text 289to standard output immediately before each attempt to read a line of input, 290whether by executing the 291.Dq N 292function or by beginning a new cycle. 293.Pp 294.It [2addr]b[label] 295Branch to the 296.Dq \&: 297function with the specified label. 298If the label is not specified, branch to the end of the script. 299.Pp 300.It [2addr]c\e 301.It text 302Delete the pattern space. 303With 0 or 1 address or at the end of a 2-address range, 304.Em text 305is written to the standard output. 306.Pp 307.It [2addr]d 308Delete the pattern space and start the next cycle. 309.Pp 310.It [2addr]D 311Delete the initial segment of the pattern space through the first 312newline character and start the next cycle. 313.Pp 314.It [2addr]g 315Replace the contents of the pattern space with the contents of the 316hold space. 317.Pp 318.It [2addr]G 319Append a newline character followed by the contents of the hold space 320to the pattern space. 321.Pp 322.It [2addr]h 323Replace the contents of the hold space with the contents of the 324pattern space. 325.Pp 326.It [2addr]H 327Append a newline character followed by the contents of the pattern space 328to the hold space. 329.Pp 330.It [1addr]i\e 331.It text 332Write 333.Em text 334to the standard output. 335.Pp 336.It [2addr]l 337(The letter ell.) 338Write the pattern space to the standard output in a visually unambiguous 339form. 340This form is as follows: 341.Pp 342.Bl -tag -width "carriage-returnXX" -offset indent -compact 343.It backslash 344\e\e 345.It alert 346\ea 347.It form-feed 348\ef 349.It carriage-return 350\er 351.It tab 352\et 353.It vertical tab 354\ev 355.El 356.Pp 357Nonprintable characters are written as three-digit octal numbers (with a 358preceding backslash) for each byte in the character (most significant byte 359first). 360Long lines are folded, with the point of folding indicated by displaying 361a backslash followed by a newline. 362The end of each line is marked with a 363.Dq $ . 364.Pp 365.It [2addr]n 366Write the pattern space to the standard output if the default output has 367not been suppressed, and replace the pattern space with the next line of 368input. 369.Pp 370.It [2addr]N 371Append the next line of input to the pattern space, using an embedded 372newline character to separate the appended material from the original 373contents. 374Note that the current line number changes. 375.Pp 376.It [2addr]p 377Write the pattern space to standard output. 378.Pp 379.It [2addr]P 380Write the pattern space, up to the first newline character to the 381standard output. 382.Pp 383.It [1addr]q 384Branch to the end of the script and quit without starting a new cycle. 385.Pp 386.It [1addr]r file 387Copy the contents of 388.Em file 389to the standard output immediately before the next attempt to read a 390line of input. 391If 392.Em file 393cannot be read for any reason, it is silently ignored and no error 394condition is set. 395.Pp 396.It [2addr]s/regular expression/replacement/flags 397Substitute the replacement string for the first instance of the regular 398expression in the pattern space. 399Any character other than backslash or newline can be used instead of 400a slash to delimit the RE and the replacement. 401Within the RE and the replacement, the RE delimiter itself can be used as 402a literal character if it is preceded by a backslash. 403.Pp 404An ampersand 405.Pq Dq & 406appearing in the replacement is replaced by the string matching the RE. 407The special meaning of 408.Dq & 409in this context can be suppressed by preceding it by a backslash. 410The string 411.Dq \e# , 412where 413.Dq # 414is a digit, is replaced by the text matched 415by the corresponding backreference expression (see 416.Xr re_format 7 ) . 417.Pp 418A line can be split by substituting a newline character into it. 419To specify a newline character in the replacement string, precede it with 420a backslash. 421.Pp 422The value of 423.Em flags 424in the substitute function is zero or more of the following: 425.Bl -tag -width "XXXXXX" -offset indent 426.It Ar N 427Make the substitution only for the 428.Ar N Ns 'th 429occurrence of the regular expression in the pattern space. 430.It g 431Make the substitution for all non-overlapping matches of the 432regular expression, not just the first one. 433.It p 434Write the pattern space to standard output if a replacement was made. 435If the replacement string is identical to that which it replaces, it 436is still considered to have been a replacement. 437.It w Em file 438Append the pattern space to 439.Em file 440if a replacement was made. 441If the replacement string is identical to that which it replaces, it 442is still considered to have been a replacement. 443.El 444.Pp 445.It [2addr]t [label] 446Branch to the 447.Dq \&: 448function bearing the label if any substitutions have been made since the 449most recent reading of an input line or execution of a 450.Dq t 451function. 452If no label is specified, branch to the end of the script. 453.Pp 454.It [2addr]w Em file 455Append the pattern space to the 456.Em file . 457.Pp 458.It [2addr]x 459Swap the contents of the pattern and hold spaces. 460.Pp 461.It [2addr]y/string1/string2/ 462Replace all occurrences of characters in 463.Em string1 464in the pattern space with the corresponding characters from 465.Em string2 . 466Any character other than a backslash or newline can be used instead of 467a slash to delimit the strings. 468Within 469.Em string1 470and 471.Em string2 , 472a backslash followed by any character other than a newline is that literal 473character, and a backslash followed by an ``n'' is replaced by a newline 474character. 475.Pp 476.It [2addr]!function 477.It [2addr]!function-list 478Apply the function or function-list only to the lines that are 479.Em not 480selected by the address(es). 481.Pp 482.It [0addr]:label 483This function does nothing; it bears a label to which the 484.Dq b 485and 486.Dq t 487commands may branch. 488.Pp 489.It [1addr]= 490Write the line number to the standard output followed by a newline 491character. 492.Pp 493.It [0addr] 494Empty lines are ignored. 495.Pp 496.It [0addr]# 497The 498.Dq # 499and the remainder of the line are ignored (treated as a comment), with 500the single exception that if the first two characters in the file are 501.Dq #n , 502the default output is suppressed. 503This is the same as specifying the 504.Fl n 505option on the command line. 506.El 507.Sh ENVIRONMENT 508The 509.Ev COLUMNS , LANG , LC_ALL , LC_CTYPE 510and 511.Ev LC_COLLATE 512environment variables affect the execution of 513.Nm 514as described in 515.Xr environ 7 . 516.Sh DIAGNOSTICS 517.Ex -std 518.Sh SEE ALSO 519.Xr awk 1 , 520.Xr ed 1 , 521.Xr grep 1 , 522.Xr regex 3 , 523.Xr re_format 7 524.Sh STANDARDS 525The 526.Nm 527utility is expected to be a superset of the 528.St -p1003.2 529specification. 530.Pp 531The 532.Fl i 533option is a non-standard 534.Fx 535extension and may not be available on other operating systems. 536.Sh HISTORY 537A 538.Nm 539command appeared in 540.At v7 . 541