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.\" 4. Neither the name of the University nor the names of its contributors 16.\" may be used to endorse or promote products derived from this software 17.\" without specific prior written permission. 18.\" 19.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29.\" SUCH DAMAGE. 30.\" 31.\" @(#)sed.1 8.2 (Berkeley) 12/30/93 32.\" $FreeBSD: src/usr.bin/sed/sed.1,v 1.46 2007/07/04 16:42:41 ssouhlal Exp $ 33.\" $DragonFly: src/usr.bin/sed/sed.1,v 1.5 2008/04/11 20:22:18 swildner Exp $ 34.\" 35.Dd April 8, 2008 36.Dt SED 1 37.Os 38.Sh NAME 39.Nm sed 40.Nd stream editor 41.Sh SYNOPSIS 42.Nm 43.Op Fl Ealn 44.Ar command 45.Op Ar 46.Nm 47.Op Fl Ealn 48.Op Fl e Ar command 49.Op Fl f Ar command_file 50.Op Fl I Ar extension 51.Op Fl i Ar extension 52.Op Ar 53.Sh DESCRIPTION 54The 55.Nm 56utility reads the specified files, or the standard input if no files 57are specified, modifying the input as specified by a list of commands. 58The input is then written to the standard output. 59.Pp 60A single command may be specified as the first argument to 61.Nm . 62Multiple commands may be specified by using the 63.Fl e 64or 65.Fl f 66options. 67All commands are applied to the input in the order they are specified 68regardless of their origin. 69.Pp 70The following options are available: 71.Bl -tag -width indent 72.It Fl E 73Interpret regular expressions as extended (modern) regular expressions 74rather than basic regular expressions (BRE's). 75The 76.Xr re_format 7 77manual page fully describes both formats. 78.It Fl a 79The files listed as parameters for the 80.Dq w 81functions are created (or truncated) before any processing begins, 82by default. 83The 84.Fl a 85option causes 86.Nm 87to delay opening each file until a command containing the related 88.Dq w 89function is applied to a line of input. 90.It Fl e Ar command 91Append the editing commands specified by the 92.Ar command 93argument 94to the list of commands. 95.It Fl f Ar command_file 96Append the editing commands found in the file 97.Ar command_file 98to the list of commands. 99The editing commands should each be listed on a separate line. 100.It Fl I Ar extension 101Edit files in-place, saving backups with the specified 102.Ar extension . 103If a zero-length 104.Ar extension 105is given, no backup will be saved. 106It is not recommended to give a zero-length 107.Ar extension 108when in-place editing files, as you risk corruption or partial content 109in situations where disk space is exhausted, etc. 110.Pp 111Note that in-place editing with 112.Fl I 113still takes place in a single continuous line address space covering 114all files, although each file preserves its individuality instead of 115forming one output stream. 116The line counter is never reset between files, address ranges can span 117file boundaries, and the 118.Dq $ 119address matches only the last line of the last file. 120(See 121.Sx "Sed Addresses" . ) 122That can lead to unexpected results in many cases of in-place editing, 123where using 124.Fl i 125is desired. 126.It Fl i Ar extension 127Edit files in-place similarly to 128.Fl I , 129but treat each file independently from other files. 130In particular, line numbers in each file start at 1, 131the 132.Dq $ 133address matches the last line of the current file, 134and address ranges are limited to the current file. 135(See 136.Sx "Sed Addresses" . ) 137The net result is as though each file were edited by a separate 138.Nm 139instance. 140.It Fl l 141Make output line buffered. 142.It Fl n 143By default, each line of input is echoed to the standard output after 144all of the commands have been applied to it. 145The 146.Fl n 147option suppresses this behavior. 148.El 149.Pp 150The form of a 151.Nm 152command is as follows: 153.Pp 154.Dl [address[,address]]function[arguments] 155.Pp 156Whitespace may be inserted before the first address and the function 157portions of the command. 158.Pp 159Normally, 160.Nm 161cyclically copies a line of input, not including its terminating newline 162character, into a 163.Em "pattern space" , 164(unless there is something left after a 165.Dq D 166function), 167applies all of the commands with addresses that select that pattern space, 168copies the pattern space to the standard output, appending a newline, and 169deletes the pattern space. 170.Pp 171Some of the functions use a 172.Em "hold space" 173to save all or part of the pattern space for subsequent retrieval. 174.Sh "Sed Addresses" 175An address is not required, but if specified must have one of the 176following formats: 177.Bl -bullet -offset indent 178.It 179a number that counts 180input lines 181cumulatively across input files (or in each file independently 182if a 183.Fl i 184option is in effect); 185.It 186a dollar 187.Pq Dq $ 188character that addresses the last line of input (or the last line 189of the current file if a 190.Fl i 191option was specified); 192.It 193a context address 194that consists of a regular expression preceded and followed by a 195delimiter. 196The closing delimiter can also optionally be followed by the 197.Dq I 198character, to indicate that the regular expression is to be matched 199in a case-insensitive way. 200.El 201.Pp 202A command line with no addresses selects every pattern space. 203.Pp 204A command line with one address selects all of the pattern spaces 205that match the address. 206.Pp 207A command line with two addresses selects an inclusive range. 208This 209range starts with the first pattern space that matches the first 210address. 211The end of the range is the next following pattern space 212that matches the second address. 213If the second address is a number 214less than or equal to the line number first selected, only that 215line is selected. 216In the case when the second address is a context 217address, 218.Nm 219does not re-match the second address against the 220pattern space that matched the first address. 221Starting at the 222first line following the selected range, 223.Nm 224starts looking again for the first address. 225.Pp 226Editing commands can be applied to non-selected pattern spaces by use 227of the exclamation character 228.Pq Dq \&! 229function. 230.Sh "Sed Regular Expressions" 231The regular expressions used in 232.Nm , 233by default, are basic regular expressions (BREs, see 234.Xr re_format 7 235for more information), but extended (modern) regular expressions can be used 236instead if the 237.Fl E 238flag is given. 239In addition, 240.Nm 241has the following two additions to regular expressions: 242.Pp 243.Bl -enum -compact 244.It 245In a context address, any character other than a backslash 246.Pq Dq \e 247or newline character may be used to delimit the regular expression. 248Also, putting a backslash character before the delimiting character 249causes the character to be treated literally. 250For example, in the context address \exabc\exdefx, the RE delimiter 251is an 252.Dq x 253and the second 254.Dq x 255stands for itself, so that the regular expression is 256.Dq abcxdef . 257.Pp 258.It 259The escape sequence \en matches a newline character embedded in the 260pattern space. 261You cannot, however, use a literal newline character in an address or 262in the substitute command. 263.El 264.Pp 265One special feature of 266.Nm 267regular expressions is that they can default to the last regular 268expression used. 269If a regular expression is empty, i.e., just the delimiter characters 270are specified, the last regular expression encountered is used instead. 271The last regular expression is defined as the last regular expression 272used as part of an address or substitute command, and at run-time, not 273compile-time. 274For example, the command 275.Dq /abc/s//XXX/ 276will substitute 277.Dq XXX 278for the pattern 279.Dq abc . 280.Sh "Sed Functions" 281In the following list of commands, the maximum number of permissible 282addresses for each command is indicated by [0addr], [1addr], or [2addr], 283representing zero, one, or two addresses. 284.Pp 285The argument 286.Em text 287consists of one or more lines. 288To embed a newline in the text, precede it with a backslash. 289Other backslashes in text are deleted and the following character 290taken literally. 291.Pp 292The 293.Dq r 294and 295.Dq w 296functions take an optional file parameter, which should be separated 297from the function letter by white space. 298Each file given as an argument to 299.Nm 300is created (or its contents truncated) before any input processing begins. 301.Pp 302The 303.Dq b , 304.Dq r , 305.Dq s , 306.Dq t , 307.Dq w , 308.Dq y , 309.Dq \&! , 310and 311.Dq \&: 312functions all accept additional arguments. 313The following synopses indicate which arguments have to be separated from 314the function letters by white space characters. 315.Pp 316Two of the functions take a function-list. 317This is a list of 318.Nm 319functions separated by newlines, as follows: 320.Bd -literal -offset indent 321{ function 322 function 323 ... 324 function 325} 326.Ed 327.Pp 328The 329.Dq { 330can be preceded by white space and can be followed by white space. 331The function can be preceded by white space. 332The terminating 333.Dq } 334must be preceded by a newline or optional white space. 335.Pp 336.Bl -tag -width "XXXXXX" -compact 337.It [2addr] function-list 338Execute function-list only when the pattern space is selected. 339.Pp 340.It [1addr]a\e 341.It text 342Write 343.Em text 344to standard output immediately before each attempt to read a line of input, 345whether by executing the 346.Dq N 347function or by beginning a new cycle. 348.Pp 349.It [2addr]b[label] 350Branch to the 351.Dq \&: 352function with the specified label. 353If the label is not specified, branch to the end of the script. 354.Pp 355.It [2addr]c\e 356.It text 357Delete the pattern space. 358With 0 or 1 address or at the end of a 2-address range, 359.Em text 360is written to the standard output. 361.Pp 362.It [2addr]d 363Delete the pattern space and start the next cycle. 364.Pp 365.It [2addr]D 366Delete the initial segment of the pattern space through the first 367newline character and start the next cycle. 368.Pp 369.It [2addr]g 370Replace the contents of the pattern space with the contents of the 371hold space. 372.Pp 373.It [2addr]G 374Append a newline character followed by the contents of the hold space 375to the pattern space. 376.Pp 377.It [2addr]h 378Replace the contents of the hold space with the contents of the 379pattern space. 380.Pp 381.It [2addr]H 382Append a newline character followed by the contents of the pattern space 383to the hold space. 384.Pp 385.It [1addr]i\e 386.It text 387Write 388.Em text 389to the standard output. 390.Pp 391.It [2addr]l 392(The letter ell.) 393Write the pattern space to the standard output in a visually unambiguous 394form. 395This form is as follows: 396.Pp 397.Bl -tag -width "carriage-returnXX" -offset indent -compact 398.It backslash 399\e\e 400.It alert 401\ea 402.It form-feed 403\ef 404.It carriage-return 405\er 406.It tab 407\et 408.It vertical tab 409\ev 410.El 411.Pp 412Nonprintable characters are written as three-digit octal numbers (with a 413preceding backslash) for each byte in the character (most significant byte 414first). 415Long lines are folded, with the point of folding indicated by displaying 416a backslash followed by a newline. 417The end of each line is marked with a 418.Dq $ . 419.Pp 420.It [2addr]n 421Write the pattern space to the standard output if the default output has 422not been suppressed, and replace the pattern space with the next line of 423input. 424.Pp 425.It [2addr]N 426Append the next line of input to the pattern space, using an embedded 427newline character to separate the appended material from the original 428contents. 429Note that the current line number changes. 430.Pp 431.It [2addr]p 432Write the pattern space to standard output. 433.Pp 434.It [2addr]P 435Write the pattern space, up to the first newline character to the 436standard output. 437.Pp 438.It [1addr]q 439Branch to the end of the script and quit without starting a new cycle. 440.Pp 441.It [1addr]r file 442Copy the contents of 443.Em file 444to the standard output immediately before the next attempt to read a 445line of input. 446If 447.Em file 448cannot be read for any reason, it is silently ignored and no error 449condition is set. 450.Pp 451.It [2addr]s/regular expression/replacement/flags 452Substitute the replacement string for the first instance of the regular 453expression in the pattern space. 454Any character other than backslash or newline can be used instead of 455a slash to delimit the RE and the replacement. 456Within the RE and the replacement, the RE delimiter itself can be used as 457a literal character if it is preceded by a backslash. 458.Pp 459An ampersand 460.Pq Dq & 461appearing in the replacement is replaced by the string matching the RE. 462The special meaning of 463.Dq & 464in this context can be suppressed by preceding it by a backslash. 465The string 466.Dq \e# , 467where 468.Dq # 469is a digit, is replaced by the text matched 470by the corresponding backreference expression (see 471.Xr re_format 7 ) . 472.Pp 473A line can be split by substituting a newline character into it. 474To specify a newline character in the replacement string, precede it with 475a backslash. 476.Pp 477The value of 478.Em flags 479in the substitute function is zero or more of the following: 480.Bl -tag -width "XXXXXX" -offset indent 481.It Ar N 482Make the substitution only for the 483.Ar N Ns 'th 484occurrence of the regular expression in the pattern space. 485.It g 486Make the substitution for all non-overlapping matches of the 487regular expression, not just the first one. 488.It p 489Write the pattern space to standard output if a replacement was made. 490If the replacement string is identical to that which it replaces, it 491is still considered to have been a replacement. 492.It w Em file 493Append the pattern space to 494.Em file 495if a replacement was made. 496If the replacement string is identical to that which it replaces, it 497is still considered to have been a replacement. 498.It I 499Match the regular expression in a case-insensitive way. 500.El 501.Pp 502.It [2addr]t [label] 503Branch to the 504.Dq \&: 505function bearing the label if any substitutions have been made since the 506most recent reading of an input line or execution of a 507.Dq t 508function. 509If no label is specified, branch to the end of the script. 510.Pp 511.It [2addr]w Em file 512Append the pattern space to the 513.Em file . 514.Pp 515.It [2addr]x 516Swap the contents of the pattern and hold spaces. 517.Pp 518.It [2addr]y/string1/string2/ 519Replace all occurrences of characters in 520.Em string1 521in the pattern space with the corresponding characters from 522.Em string2 . 523Any character other than a backslash or newline can be used instead of 524a slash to delimit the strings. 525Within 526.Em string1 527and 528.Em string2 , 529a backslash followed by any character other than a newline is that literal 530character, and a backslash followed by an ``n'' is replaced by a newline 531character. 532.Pp 533.It [2addr]!function 534.It [2addr]!function-list 535Apply the function or function-list only to the lines that are 536.Em not 537selected by the address(es). 538.Pp 539.It [0addr]:label 540This function does nothing; it bears a label to which the 541.Dq b 542and 543.Dq t 544commands may branch. 545.Pp 546.It [1addr]= 547Write the line number to the standard output followed by a newline 548character. 549.Pp 550.It [0addr] 551Empty lines are ignored. 552.Pp 553.It [0addr]# 554The 555.Dq # 556and the remainder of the line are ignored (treated as a comment), with 557the single exception that if the first two characters in the file are 558.Dq #n , 559the default output is suppressed. 560This is the same as specifying the 561.Fl n 562option on the command line. 563.El 564.Sh ENVIRONMENT 565The 566.Ev COLUMNS , LANG , LC_ALL , LC_CTYPE 567and 568.Ev LC_COLLATE 569environment variables affect the execution of 570.Nm 571as described in 572.Xr environ 7 . 573.Sh EXIT STATUS 574.Ex -std 575.Sh SEE ALSO 576.Xr awk 1 , 577.Xr ed 1 , 578.Xr grep 1 , 579.Xr regex 3 , 580.Xr re_format 7 581.Sh STANDARDS 582The 583.Nm 584utility is expected to be a superset of the 585.St -p1003.2 586specification. 587.Pp 588The 589.Fl E , I , a 590and 591.Fl i 592options, as well as the 593.Dq I 594flag to the address regular expression and substitution command are 595non-standard 596.Dx 597extensions and may not be available on other operating systems. 598.Sh HISTORY 599A 600.Nm 601command, written by 602.An L. E. McMahon , 603appeared in 604.At v7 . 605.Sh AUTHORS 606.An "Diomidis D. Spinellis" Aq dds@FreeBSD.org 607.Sh BUGS 608Multibyte characters containing a byte with value 0x5C 609.Tn ( ASCII 610.Ql \e ) 611may be incorrectly treated as line continuation characters in arguments to the 612.Dq a , 613.Dq c 614and 615.Dq i 616commands. 617Multibyte characters cannot be used as delimiters with the 618.Dq s 619and 620.Dq y 621commands. 622