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. 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 1.50 2009/05/25 21:29:06 brian Exp $ 33.\" 34.Dd December 9, 2013 35.Dt SED 1 36.Os 37.Sh NAME 38.Nm sed 39.Nd stream editor 40.Sh SYNOPSIS 41.Nm 42.Op Fl Ealnr 43.Ar command 44.Op Ar 45.Nm 46.Op Fl Ealnr 47.Op Fl e Ar command 48.Op Fl f Ar command_file 49.Op Fl I Ar extension 50.Op Fl i Ar extension 51.Op Ar 52.Sh DESCRIPTION 53The 54.Nm 55utility reads the specified files, or the standard input if no files 56are specified, modifying the input as specified by a list of commands. 57The input is then written to the standard output. 58.Pp 59A single command may be specified as the first argument to 60.Nm . 61Multiple commands may be specified by using the 62.Fl e 63or 64.Fl f 65options. 66All commands are applied to the input in the order they are specified 67regardless of their origin. 68.Pp 69The following options are available: 70.Bl -tag -width indent 71.It Fl E 72Interpret regular expressions as extended (modern) regular expressions 73rather than basic regular expressions (BRE's). 74The 75.Xr re_format 7 76manual page fully describes both formats. 77.It Fl a 78The files listed as parameters for the 79.Dq w 80functions are created (or truncated) before any processing begins, 81by default. 82The 83.Fl a 84option causes 85.Nm 86to delay opening each file until a command containing the related 87.Dq w 88function is applied to a line of input. 89.It Fl e Ar command 90Append the editing commands specified by the 91.Ar command 92argument 93to the list of commands. 94.It Fl f Ar command_file 95Append the editing commands found in the file 96.Ar command_file 97to the list of commands. 98The editing commands should each be listed on a separate line. 99.It Fl I Ar extension 100Edit files in-place, saving backups with the specified 101.Ar extension . 102If a zero-length 103.Ar extension 104is given, no backup will be saved. 105It is not recommended to give a zero-length 106.Ar extension 107when in-place editing files, as you risk corruption or partial content 108in situations where disk space is exhausted, etc. 109.Pp 110Note that in-place editing with 111.Fl I 112still takes place in a single continuous line address space covering 113all files, although each file preserves its individuality instead of 114forming one output stream. 115The line counter is never reset between files, address ranges can span 116file boundaries, and the 117.Dq $ 118address matches only the last line of the last file. 119(See 120.Sx SED ADDRESSES . ) 121That can lead to unexpected results in many cases of in-place editing, 122where using 123.Fl i 124is desired. 125.It Fl i Ar extension 126Edit files in-place similarly to 127.Fl I , 128but treat each file independently from other files. 129In particular, line numbers in each file start at 1, 130the 131.Dq $ 132address matches the last line of the current file, 133and address ranges are limited to the current file. 134(See 135.Sx SED ADDRESSES . ) 136The net result is as though each file were edited by a separate 137.Nm 138instance. 139.It Fl l 140Make output line buffered. 141.It Fl n 142By default, each line of input is echoed to the standard output after 143all of the commands have been applied to it. 144The 145.Fl n 146option suppresses this behavior. 147.It Fl r 148Same as 149.Fl E 150for compatibility with GNU sed. 151.El 152.Pp 153The form of a 154.Nm 155command is as follows: 156.Pp 157.Dl [address[,address]]function[arguments] 158.Pp 159Whitespace may be inserted before the first address and the function 160portions of the command. 161.Pp 162Normally, 163.Nm 164cyclically copies a line of input, not including its terminating newline 165character, into a 166.Em "pattern space" , 167(unless there is something left after a 168.Dq D 169function), 170applies all of the commands with addresses that select that pattern space, 171copies the pattern space to the standard output, appending a newline, and 172deletes the pattern space. 173.Pp 174Some of the functions use a 175.Em "hold space" 176to save all or part of the pattern space for subsequent retrieval. 177.Sh SED ADDRESSES 178An address is not required, but if specified must have one of the 179following formats: 180.Bl -bullet -offset indent 181.It 182a number that counts 183input lines 184cumulatively across input files (or in each file independently 185if a 186.Fl i 187option is in effect); 188.It 189a dollar 190.Pq Dq $ 191character that addresses the last line of input (or the last line 192of the current file if a 193.Fl i 194option was specified); 195.It 196a context address 197that consists of a regular expression preceded and followed by a 198delimiter. 199The closing delimiter can also optionally be followed by the 200.Dq i 201character, to indicate that the regular expression is to be matched 202in a case-insensitive way. 203.El 204.Pp 205A command line with no addresses selects every pattern space. 206.Pp 207A command line with one address selects all of the pattern spaces 208that match the address. 209.Pp 210A command line with two addresses selects an inclusive range. 211This 212range starts with the first pattern space that matches the first 213address. 214The end of the range is the next following pattern space 215that matches the second address. 216If the second address is a number 217less than or equal to the line number first selected, only that 218line is selected. 219The number in the second address may be prefixed with a 220.Pq Dq \&+ 221to specify the number of lines to match after the first pattern. 222In the case when the second address is a context 223address, 224.Nm 225does not re-match the second address against the 226pattern space that matched the first address. 227Starting at the 228first line following the selected range, 229.Nm 230starts looking again for the first address. 231.Pp 232Editing commands can be applied to non-selected pattern spaces by use 233of the exclamation character 234.Pq Dq \&! 235function. 236.Sh SED REGULAR EXPRESSIONS 237The regular expressions used in 238.Nm , 239by default, are basic regular expressions (BREs, see 240.Xr re_format 7 241for more information), but extended (modern) regular expressions can be used 242instead if the 243.Fl E 244flag is given. 245In addition, 246.Nm 247has the following two additions to regular expressions: 248.Pp 249.Bl -enum -compact 250.It 251In a context address, any character other than a backslash 252.Pq Dq \e 253or newline character may be used to delimit the regular expression. 254The opening delimiter needs to be preceded by a backslash 255unless it is a slash. 256For example, the context address 257.Li \exabcx 258is equivalent to 259.Li /abc/ . 260Also, putting a backslash character before the delimiting character 261within the regular expression causes the character to be treated literally. 262For example, in the context address 263.Li \exabc\exdefx , 264the RE delimiter is an 265.Dq x 266and the second 267.Dq x 268stands for itself, so that the regular expression is 269.Dq abcxdef . 270.Pp 271.It 272The escape sequence \en matches a newline character embedded in the 273pattern space. 274You cannot, however, use a literal newline character in an address or 275in the substitute command. 276.El 277.Pp 278One special feature of 279.Nm 280regular expressions is that they can default to the last regular 281expression used. 282If a regular expression is empty, i.e., just the delimiter characters 283are specified, the last regular expression encountered is used instead. 284The last regular expression is defined as the last regular expression 285used as part of an address or substitute command, and at run-time, not 286compile-time. 287For example, the command 288.Dq /abc/s//XXX/ 289will substitute 290.Dq XXX 291for the pattern 292.Dq abc . 293.Sh SED FUNCTIONS 294In the following list of commands, the maximum number of permissible 295addresses for each command is indicated by [0addr], [1addr], or [2addr], 296representing zero, one, or two addresses. 297.Pp 298The argument 299.Em text 300consists of one or more lines. 301To embed a newline in the text, precede it with a backslash. 302Other backslashes in text are deleted and the following character 303taken literally. 304.Pp 305The 306.Dq r 307and 308.Dq w 309functions take an optional file parameter, which should be separated 310from the function letter by white space. 311Each file given as an argument to 312.Nm 313is created (or its contents truncated) before any input processing begins. 314.Pp 315The 316.Dq b , 317.Dq r , 318.Dq s , 319.Dq t , 320.Dq w , 321.Dq y , 322.Dq \&! , 323and 324.Dq \&: 325functions all accept additional arguments. 326The following synopses indicate which arguments have to be separated from 327the function letters by white space characters. 328.Pp 329Two of the functions take a function-list. 330This is a list of 331.Nm 332functions separated by newlines, as follows: 333.Bd -literal -offset indent 334{ function 335 function 336 ... 337 function 338} 339.Ed 340.Pp 341The 342.Dq { 343can be preceded by white space and can be followed by white space. 344The function can be preceded by white space. 345The terminating 346.Dq } 347must be preceded by a newline or optional white space. 348.Pp 349.Bl -tag -width "XXXXXX" -compact 350.It [2addr] function-list 351Execute function-list only when the pattern space is selected. 352.Pp 353.It [1addr]a\e 354.It text 355Write 356.Em text 357to standard output immediately before each attempt to read a line of input, 358whether by executing the 359.Dq N 360function or by beginning a new cycle. 361.Pp 362.It [2addr]b[label] 363Branch to the 364.Dq \&: 365function with the specified label. 366If the label is not specified, branch to the end of the script. 367.Pp 368.It [2addr]c\e 369.It text 370Delete the pattern space. 371With 0 or 1 address or at the end of a 2-address range, 372.Em text 373is written to the standard output. 374.Pp 375.It [2addr]d 376Delete the pattern space and start the next cycle. 377.Pp 378.It [2addr]D 379Delete the initial segment of the pattern space through the first 380newline character and start the next cycle. 381.Pp 382.It [2addr]g 383Replace the contents of the pattern space with the contents of the 384hold space. 385.Pp 386.It [2addr]G 387Append a newline character followed by the contents of the hold space 388to the pattern space. 389.Pp 390.It [2addr]h 391Replace the contents of the hold space with the contents of the 392pattern space. 393.Pp 394.It [2addr]H 395Append a newline character followed by the contents of the pattern space 396to the hold space. 397.Pp 398.It [1addr]i\e 399.It text 400Write 401.Em text 402to the standard output. 403.Pp 404.It [2addr]l 405(The letter ell.) 406Write the pattern space to the standard output in a visually unambiguous 407form. 408This form is as follows: 409.Pp 410.Bl -tag -width "carriage-returnXX" -offset indent -compact 411.It backslash 412\e\e 413.It alert 414\ea 415.It form-feed 416\ef 417.It carriage-return 418\er 419.It tab 420\et 421.It vertical tab 422\ev 423.El 424.Pp 425Nonprintable characters are written as three-digit octal numbers (with a 426preceding backslash) for each byte in the character (most significant byte 427first). 428Long lines are folded, with the point of folding indicated by displaying 429a backslash followed by a newline. 430The end of each line is marked with a 431.Dq $ . 432.Pp 433.It [2addr]n 434Write the pattern space to the standard output if the default output has 435not been suppressed, and replace the pattern space with the next line of 436input. 437.Pp 438.It [2addr]N 439Append the next line of input to the pattern space, using an embedded 440newline character to separate the appended material from the original 441contents. 442Note that the current line number changes. 443.Pp 444.It [2addr]p 445Write the pattern space to standard output. 446.Pp 447.It [2addr]P 448Write the pattern space, up to the first newline character to the 449standard output. 450.Pp 451.It [1addr]q 452Branch to the end of the script and quit without starting a new cycle. 453.Pp 454.It [1addr]r file 455Copy the contents of 456.Em file 457to the standard output immediately before the next attempt to read a 458line of input. 459If 460.Em file 461cannot be read for any reason, it is silently ignored and no error 462condition is set. 463.Pp 464.It [2addr]s/regular expression/replacement/flags 465Substitute the replacement string for the first instance of the regular 466expression in the pattern space. 467Any character other than backslash or newline can be used instead of 468a slash to delimit the RE and the replacement. 469Within the RE and the replacement, the RE delimiter itself can be used as 470a literal character if it is preceded by a backslash. 471.Pp 472An ampersand 473.Pq Dq & 474appearing in the replacement is replaced by the string matching the RE. 475The special meaning of 476.Dq & 477in this context can be suppressed by preceding it by a backslash. 478The string 479.Dq \e# , 480where 481.Dq # 482is a digit, is replaced by the text matched 483by the corresponding backreference expression (see 484.Xr re_format 7 ) . 485.Pp 486A line can be split by substituting a newline character into it. 487To specify a newline character in the replacement string, precede it with 488a backslash. 489.Pp 490The value of 491.Em flags 492in the substitute function is zero or more of the following: 493.Bl -tag -width "XXXXXX" -offset indent 494.It Ar N 495Make the substitution only for the 496.Ar N Ns 'th 497occurrence of the regular expression in the pattern space. 498.It g 499Make the substitution for all non-overlapping matches of the 500regular expression, not just the first one. 501.It p 502Write the pattern space to standard output if a replacement was made. 503If the replacement string is identical to that which it replaces, it 504is still considered to have been a replacement. 505.It w Em file 506Append the pattern space to 507.Em file 508if a replacement was made. 509If the replacement string is identical to that which it replaces, it 510is still considered to have been a replacement. 511.It i or I 512Match the regular expression in a case-insensitive way. 513.El 514.Pp 515.It [2addr]t [label] 516Branch to the 517.Dq \&: 518function bearing the label if any substitutions have been made since the 519most recent reading of an input line or execution of a 520.Dq t 521function. 522If no label is specified, branch to the end of the script. 523.Pp 524.It [2addr]w Em file 525Append the pattern space to the 526.Em file . 527.Pp 528.It [2addr]x 529Swap the contents of the pattern and hold spaces. 530.Pp 531.It [2addr]y/string1/string2/ 532Replace all occurrences of characters in 533.Em string1 534in the pattern space with the corresponding characters from 535.Em string2 . 536Any character other than a backslash or newline can be used instead of 537a slash to delimit the strings. 538Within 539.Em string1 540and 541.Em string2 , 542a backslash followed by any character other than a newline is that literal 543character, and a backslash followed by an ``n'' is replaced by a newline 544character. 545.Pp 546.It [2addr]!function 547.It [2addr]!function-list 548Apply the function or function-list only to the lines that are 549.Em not 550selected by the address(es). 551.Pp 552.It [0addr]:label 553This function does nothing; it bears a label to which the 554.Dq b 555and 556.Dq t 557commands may branch. 558.Pp 559.It [1addr]= 560Write the line number to the standard output followed by a newline 561character. 562.Pp 563.It [0addr] 564Empty lines are ignored. 565.Pp 566.It [0addr]# 567The 568.Dq # 569and the remainder of the line are ignored (treated as a comment), with 570the single exception that if the first two characters in the file are 571.Dq #n , 572the default output is suppressed. 573This is the same as specifying the 574.Fl n 575option on the command line. 576.El 577.Sh ENVIRONMENT 578The 579.Ev COLUMNS , LANG , LC_ALL , LC_CTYPE 580and 581.Ev LC_COLLATE 582environment variables affect the execution of 583.Nm 584as described in 585.Xr environ 7 . 586.Sh EXIT STATUS 587.Ex -std 588.Sh SEE ALSO 589.Xr awk 1 , 590.Xr ed 1 , 591.Xr grep 1 , 592.Xr regex 3 , 593.Xr re_format 7 594.Sh STANDARDS 595The 596.Nm 597utility is expected to be a superset of the 598.St -p1003.2 599specification. 600.Pp 601The 602.Fl E , I , a 603and 604.Fl i 605options, the prefixing 606.Dq \&+ 607in the second member of an address range, 608as well as the 609.Dq I 610flag to the address regular expression and substitution command are 611non-standard 612.Dx 613extensions and may not be available on other operating systems. 614.Sh HISTORY 615A 616.Nm 617command, written by 618.An L. E. McMahon , 619appeared in 620.At v7 . 621.Sh AUTHORS 622.An Diomidis D. Spinellis Aq Mt dds@FreeBSD.org 623.Sh BUGS 624Multibyte characters containing a byte with value 0x5C 625.Tn ( ASCII 626.Ql \e ) 627may be incorrectly treated as line continuation characters in arguments to the 628.Dq a , 629.Dq c 630and 631.Dq i 632commands. 633Multibyte characters cannot be used as delimiters with the 634.Dq s 635and 636.Dq y 637commands. 638