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 July 17, 2004 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. 159This 160range starts with the first pattern space that matches the first 161address. 162The end of the range is the next following pattern space 163that matches the second address. 164If the second address is a number 165less than or equal to the line number first selected, only that 166line is selected. 167In the case when the second address is a context 168address, 169.Nm 170does not re-match the second address against the 171pattern space that matched the first address. 172Starting at the 173first line following the selected range, 174.Nm 175starts looking again for the first address. 176.Pp 177Editing commands can be applied to non-selected pattern spaces by use 178of the exclamation character 179.Pq Dq \&! 180function. 181.Sh "Sed Regular Expressions" 182The regular expressions used in 183.Nm , 184by default, are basic regular expressions (BREs, see 185.Xr re_format 7 186for more information), but extended (modern) regular expressions can be used 187instead if the 188.Fl E 189flag is given. 190In addition, 191.Nm 192has the following two additions to regular expressions: 193.Pp 194.Bl -enum -compact 195.It 196In a context address, any character other than a backslash 197.Pq Dq \e 198or newline character may be used to delimit the regular expression. 199Also, putting a backslash character before the delimiting character 200causes the character to be treated literally. 201For example, in the context address \exabc\exdefx, the RE delimiter 202is an 203.Dq x 204and the second 205.Dq x 206stands for itself, so that the regular expression is 207.Dq abcxdef . 208.Pp 209.It 210The escape sequence \en matches a newline character embedded in the 211pattern space. 212You can't, however, use a literal newline character in an address or 213in the substitute command. 214.El 215.Pp 216One special feature of 217.Nm 218regular expressions is that they can default to the last regular 219expression used. 220If a regular expression is empty, i.e., just the delimiter characters 221are specified, the last regular expression encountered is used instead. 222The last regular expression is defined as the last regular expression 223used as part of an address or substitute command, and at run-time, not 224compile-time. 225For example, the command 226.Dq /abc/s//XXX/ 227will substitute 228.Dq XXX 229for the pattern 230.Dq abc . 231.Sh "Sed Functions" 232In the following list of commands, the maximum number of permissible 233addresses for each command is indicated by [0addr], [1addr], or [2addr], 234representing zero, one, or two addresses. 235.Pp 236The argument 237.Em text 238consists of one or more lines. 239To embed a newline in the text, precede it with a backslash. 240Other backslashes in text are deleted and the following character 241taken literally. 242.Pp 243The 244.Dq r 245and 246.Dq w 247functions take an optional file parameter, which should be separated 248from the function letter by white space. 249Each file given as an argument to 250.Nm 251is created (or its contents truncated) before any input processing begins. 252.Pp 253The 254.Dq b , 255.Dq r , 256.Dq s , 257.Dq t , 258.Dq w , 259.Dq y , 260.Dq \&! , 261and 262.Dq \&: 263functions all accept additional arguments. 264The following synopses indicate which arguments have to be separated from 265the function letters by white space characters. 266.Pp 267Two of the functions take a function-list. 268This is a list of 269.Nm 270functions separated by newlines, as follows: 271.Bd -literal -offset indent 272{ function 273 function 274 ... 275 function 276} 277.Ed 278.Pp 279The 280.Dq { 281can be preceded by white space and can be followed by white space. 282The function can be preceded by white space. 283The terminating 284.Dq } 285must be preceded by a newline or optional white space. 286.Pp 287.Bl -tag -width "XXXXXX" -compact 288.It [2addr] function-list 289Execute function-list only when the pattern space is selected. 290.Pp 291.It [1addr]a\e 292.It text 293Write 294.Em text 295to standard output immediately before each attempt to read a line of input, 296whether by executing the 297.Dq N 298function or by beginning a new cycle. 299.Pp 300.It [2addr]b[label] 301Branch to the 302.Dq \&: 303function with the specified label. 304If the label is not specified, branch to the end of the script. 305.Pp 306.It [2addr]c\e 307.It text 308Delete the pattern space. 309With 0 or 1 address or at the end of a 2-address range, 310.Em text 311is written to the standard output. 312.Pp 313.It [2addr]d 314Delete the pattern space and start the next cycle. 315.Pp 316.It [2addr]D 317Delete the initial segment of the pattern space through the first 318newline character and start the next cycle. 319.Pp 320.It [2addr]g 321Replace the contents of the pattern space with the contents of the 322hold space. 323.Pp 324.It [2addr]G 325Append a newline character followed by the contents of the hold space 326to the pattern space. 327.Pp 328.It [2addr]h 329Replace the contents of the hold space with the contents of the 330pattern space. 331.Pp 332.It [2addr]H 333Append a newline character followed by the contents of the pattern space 334to the hold space. 335.Pp 336.It [1addr]i\e 337.It text 338Write 339.Em text 340to the standard output. 341.Pp 342.It [2addr]l 343(The letter ell.) 344Write the pattern space to the standard output in a visually unambiguous 345form. 346This form is as follows: 347.Pp 348.Bl -tag -width "carriage-returnXX" -offset indent -compact 349.It backslash 350\e\e 351.It alert 352\ea 353.It form-feed 354\ef 355.It carriage-return 356\er 357.It tab 358\et 359.It vertical tab 360\ev 361.El 362.Pp 363Nonprintable characters are written as three-digit octal numbers (with a 364preceding backslash) for each byte in the character (most significant byte 365first). 366Long lines are folded, with the point of folding indicated by displaying 367a backslash followed by a newline. 368The end of each line is marked with a 369.Dq $ . 370.Pp 371.It [2addr]n 372Write the pattern space to the standard output if the default output has 373not been suppressed, and replace the pattern space with the next line of 374input. 375.Pp 376.It [2addr]N 377Append the next line of input to the pattern space, using an embedded 378newline character to separate the appended material from the original 379contents. 380Note that the current line number changes. 381.Pp 382.It [2addr]p 383Write the pattern space to standard output. 384.Pp 385.It [2addr]P 386Write the pattern space, up to the first newline character to the 387standard output. 388.Pp 389.It [1addr]q 390Branch to the end of the script and quit without starting a new cycle. 391.Pp 392.It [1addr]r file 393Copy the contents of 394.Em file 395to the standard output immediately before the next attempt to read a 396line of input. 397If 398.Em file 399cannot be read for any reason, it is silently ignored and no error 400condition is set. 401.Pp 402.It [2addr]s/regular expression/replacement/flags 403Substitute the replacement string for the first instance of the regular 404expression in the pattern space. 405Any character other than backslash or newline can be used instead of 406a slash to delimit the RE and the replacement. 407Within the RE and the replacement, the RE delimiter itself can be used as 408a literal character if it is preceded by a backslash. 409.Pp 410An ampersand 411.Pq Dq & 412appearing in the replacement is replaced by the string matching the RE. 413The special meaning of 414.Dq & 415in this context can be suppressed by preceding it by a backslash. 416The string 417.Dq \e# , 418where 419.Dq # 420is a digit, is replaced by the text matched 421by the corresponding backreference expression (see 422.Xr re_format 7 ) . 423.Pp 424A line can be split by substituting a newline character into it. 425To specify a newline character in the replacement string, precede it with 426a backslash. 427.Pp 428The value of 429.Em flags 430in the substitute function is zero or more of the following: 431.Bl -tag -width "XXXXXX" -offset indent 432.It Ar N 433Make the substitution only for the 434.Ar N Ns 'th 435occurrence of the regular expression in the pattern space. 436.It g 437Make the substitution for all non-overlapping matches of the 438regular expression, not just the first one. 439.It p 440Write the pattern space to standard output if 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.It w Em file 444Append the pattern space to 445.Em file 446if a replacement was made. 447If the replacement string is identical to that which it replaces, it 448is still considered to have been a replacement. 449.El 450.Pp 451.It [2addr]t [label] 452Branch to the 453.Dq \&: 454function bearing the label if any substitutions have been made since the 455most recent reading of an input line or execution of a 456.Dq t 457function. 458If no label is specified, branch to the end of the script. 459.Pp 460.It [2addr]w Em file 461Append the pattern space to the 462.Em file . 463.Pp 464.It [2addr]x 465Swap the contents of the pattern and hold spaces. 466.Pp 467.It [2addr]y/string1/string2/ 468Replace all occurrences of characters in 469.Em string1 470in the pattern space with the corresponding characters from 471.Em string2 . 472Any character other than a backslash or newline can be used instead of 473a slash to delimit the strings. 474Within 475.Em string1 476and 477.Em string2 , 478a backslash followed by any character other than a newline is that literal 479character, and a backslash followed by an ``n'' is replaced by a newline 480character. 481.Pp 482.It [2addr]!function 483.It [2addr]!function-list 484Apply the function or function-list only to the lines that are 485.Em not 486selected by the address(es). 487.Pp 488.It [0addr]:label 489This function does nothing; it bears a label to which the 490.Dq b 491and 492.Dq t 493commands may branch. 494.Pp 495.It [1addr]= 496Write the line number to the standard output followed by a newline 497character. 498.Pp 499.It [0addr] 500Empty lines are ignored. 501.Pp 502.It [0addr]# 503The 504.Dq # 505and the remainder of the line are ignored (treated as a comment), with 506the single exception that if the first two characters in the file are 507.Dq #n , 508the default output is suppressed. 509This is the same as specifying the 510.Fl n 511option on the command line. 512.El 513.Sh ENVIRONMENT 514The 515.Ev COLUMNS , LANG , LC_ALL , LC_CTYPE 516and 517.Ev LC_COLLATE 518environment variables affect the execution of 519.Nm 520as described in 521.Xr environ 7 . 522.Sh DIAGNOSTICS 523.Ex -std 524.Sh SEE ALSO 525.Xr awk 1 , 526.Xr ed 1 , 527.Xr grep 1 , 528.Xr regex 3 , 529.Xr re_format 7 530.Sh STANDARDS 531The 532.Nm 533utility is expected to be a superset of the 534.St -p1003.2 535specification. 536.Pp 537The 538.Fl E , 539.Fl a 540and 541.Fl i 542options are non-standard 543.Fx 544extensions and may not be available on other operating systems. 545.Sh HISTORY 546A 547.Nm 548command, written by 549.An L. E. McMahon , 550appeared in 551.At v7 . 552.Sh AUTHORS 553.An "Diomidis D. Spinellis" Aq dds@FreeBSD.org 554.Sh BUGS 555Multibyte characters containing a byte with value 0x5C 556.No ( Ns 557.Tn ASCII 558.Ql \e Ns ) 559may be incorrectly treated as line continuation characters in arguments to the 560.Dq a , 561.Dq c 562and 563.Dq i 564commands. 565Multibyte characters cannot be used as delimiters with the 566.Dq s 567and 568.Dq y 569commands. 570