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, 165.Nm 166does not re-match the second address against the 167pattern space that matched the first address. Starting at the 168first line following the selected range, 169.Nm 170starts looking again for the first address. 171.Pp 172Editing commands can be applied to non-selected pattern spaces by use 173of the exclamation character 174.Pq Dq \&! 175function. 176.Sh "Sed Regular Expressions" 177The regular expressions used in 178.Nm , 179by default, are basic regular expressions (BREs, see 180.Xr re_format 7 181for more information), but extended (modern) regular expressions can be used 182instead if the 183.Fl E 184flag is given. 185In addition, 186.Nm 187has the following two additions to regular expressions: 188.Pp 189.Bl -enum -compact 190.It 191In a context address, any character other than a backslash 192.Pq Dq \e 193or newline character may be used to delimit the regular expression. 194Also, putting a backslash character before the delimiting character 195causes the character to be treated literally. 196For example, in the context address \exabc\exdefx, the RE delimiter 197is an 198.Dq x 199and the second 200.Dq x 201stands for itself, so that the regular expression is 202.Dq abcxdef . 203.Pp 204.It 205The escape sequence \en matches a newline character embedded in the 206pattern space. 207You can't, however, use a literal newline character in an address or 208in the substitute command. 209.El 210.Pp 211One special feature of 212.Nm 213regular expressions is that they can default to the last regular 214expression used. 215If a regular expression is empty, i.e. just the delimiter characters 216are specified, the last regular expression encountered is used instead. 217The last regular expression is defined as the last regular expression 218used as part of an address or substitute command, and at run-time, not 219compile-time. 220For example, the command 221.Dq /abc/s//XXX/ 222will substitute 223.Dq XXX 224for the pattern 225.Dq abc . 226.Sh "Sed Functions" 227In the following list of commands, the maximum number of permissible 228addresses for each command is indicated by [0addr], [1addr], or [2addr], 229representing zero, one, or two addresses. 230.Pp 231The argument 232.Em text 233consists of one or more lines. 234To embed a newline in the text, precede it with a backslash. 235Other backslashes in text are deleted and the following character 236taken literally. 237.Pp 238The 239.Dq r 240and 241.Dq w 242functions take an optional file parameter, which should be separated 243from the function letter by white space. 244Each file given as an argument to 245.Nm 246is created (or its contents truncated) before any input processing begins. 247.Pp 248The 249.Dq b , 250.Dq r , 251.Dq s , 252.Dq t , 253.Dq w , 254.Dq y , 255.Dq \&! , 256and 257.Dq \&: 258functions all accept additional arguments. 259The following synopses indicate which arguments have to be separated from 260the function letters by white space characters. 261.Pp 262Two of the functions take a function-list. 263This is a list of 264.Nm 265functions separated by newlines, as follows: 266.Bd -literal -offset indent 267{ function 268 function 269 ... 270 function 271} 272.Ed 273.Pp 274The 275.Dq { 276can be preceded by white space and can be followed by white space. 277The function can be preceded by white space. 278The terminating 279.Dq } 280must be preceded by a newline or optional white space. 281.Pp 282.Bl -tag -width "XXXXXX" -compact 283.It [2addr] function-list 284Execute function-list only when the pattern space is selected. 285.Pp 286.It [1addr]a\e 287.It text 288Write 289.Em text 290to standard output immediately before each attempt to read a line of input, 291whether by executing the 292.Dq N 293function or by beginning a new cycle. 294.Pp 295.It [2addr]b[label] 296Branch to the 297.Dq \&: 298function with the specified label. 299If the label is not specified, branch to the end of the script. 300.Pp 301.It [2addr]c\e 302.It text 303Delete the pattern space. 304With 0 or 1 address or at the end of a 2-address range, 305.Em text 306is written to the standard output. 307.Pp 308.It [2addr]d 309Delete the pattern space and start the next cycle. 310.Pp 311.It [2addr]D 312Delete the initial segment of the pattern space through the first 313newline character and start the next cycle. 314.Pp 315.It [2addr]g 316Replace the contents of the pattern space with the contents of the 317hold space. 318.Pp 319.It [2addr]G 320Append a newline character followed by the contents of the hold space 321to the pattern space. 322.Pp 323.It [2addr]h 324Replace the contents of the hold space with the contents of the 325pattern space. 326.Pp 327.It [2addr]H 328Append a newline character followed by the contents of the pattern space 329to the hold space. 330.Pp 331.It [1addr]i\e 332.It text 333Write 334.Em text 335to the standard output. 336.Pp 337.It [2addr]l 338(The letter ell.) 339Write the pattern space to the standard output in a visually unambiguous 340form. 341This form is as follows: 342.Pp 343.Bl -tag -width "carriage-returnXX" -offset indent -compact 344.It backslash 345\e\e 346.It alert 347\ea 348.It form-feed 349\ef 350.It carriage-return 351\er 352.It tab 353\et 354.It vertical tab 355\ev 356.El 357.Pp 358Nonprintable characters are written as three-digit octal numbers (with a 359preceding backslash) for each byte in the character (most significant byte 360first). 361Long lines are folded, with the point of folding indicated by displaying 362a backslash followed by a newline. 363The end of each line is marked with a 364.Dq $ . 365.Pp 366.It [2addr]n 367Write the pattern space to the standard output if the default output has 368not been suppressed, and replace the pattern space with the next line of 369input. 370.Pp 371.It [2addr]N 372Append the next line of input to the pattern space, using an embedded 373newline character to separate the appended material from the original 374contents. 375Note that the current line number changes. 376.Pp 377.It [2addr]p 378Write the pattern space to standard output. 379.Pp 380.It [2addr]P 381Write the pattern space, up to the first newline character to the 382standard output. 383.Pp 384.It [1addr]q 385Branch to the end of the script and quit without starting a new cycle. 386.Pp 387.It [1addr]r file 388Copy the contents of 389.Em file 390to the standard output immediately before the next attempt to read a 391line of input. 392If 393.Em file 394cannot be read for any reason, it is silently ignored and no error 395condition is set. 396.Pp 397.It [2addr]s/regular expression/replacement/flags 398Substitute the replacement string for the first instance of the regular 399expression in the pattern space. 400Any character other than backslash or newline can be used instead of 401a slash to delimit the RE and the replacement. 402Within the RE and the replacement, the RE delimiter itself can be used as 403a literal character if it is preceded by a backslash. 404.Pp 405An ampersand 406.Pq Dq & 407appearing in the replacement is replaced by the string matching the RE. 408The special meaning of 409.Dq & 410in this context can be suppressed by preceding it by a backslash. 411The string 412.Dq \e# , 413where 414.Dq # 415is a digit, is replaced by the text matched 416by the corresponding backreference expression (see 417.Xr re_format 7 ) . 418.Pp 419A line can be split by substituting a newline character into it. 420To specify a newline character in the replacement string, precede it with 421a backslash. 422.Pp 423The value of 424.Em flags 425in the substitute function is zero or more of the following: 426.Bl -tag -width "XXXXXX" -offset indent 427.It Ar N 428Make the substitution only for the 429.Ar N Ns 'th 430occurrence of the regular expression in the pattern space. 431.It g 432Make the substitution for all non-overlapping matches of the 433regular expression, not just the first one. 434.It p 435Write the pattern space to standard output if a replacement was made. 436If the replacement string is identical to that which it replaces, it 437is still considered to have been a replacement. 438.It w Em file 439Append the pattern space to 440.Em file 441if a replacement was made. 442If the replacement string is identical to that which it replaces, it 443is still considered to have been a replacement. 444.El 445.Pp 446.It [2addr]t [label] 447Branch to the 448.Dq \&: 449function bearing the label if any substitutions have been made since the 450most recent reading of an input line or execution of a 451.Dq t 452function. 453If no label is specified, branch to the end of the script. 454.Pp 455.It [2addr]w Em file 456Append the pattern space to the 457.Em file . 458.Pp 459.It [2addr]x 460Swap the contents of the pattern and hold spaces. 461.Pp 462.It [2addr]y/string1/string2/ 463Replace all occurrences of characters in 464.Em string1 465in the pattern space with the corresponding characters from 466.Em string2 . 467Any character other than a backslash or newline can be used instead of 468a slash to delimit the strings. 469Within 470.Em string1 471and 472.Em string2 , 473a backslash followed by any character other than a newline is that literal 474character, and a backslash followed by an ``n'' is replaced by a newline 475character. 476.Pp 477.It [2addr]!function 478.It [2addr]!function-list 479Apply the function or function-list only to the lines that are 480.Em not 481selected by the address(es). 482.Pp 483.It [0addr]:label 484This function does nothing; it bears a label to which the 485.Dq b 486and 487.Dq t 488commands may branch. 489.Pp 490.It [1addr]= 491Write the line number to the standard output followed by a newline 492character. 493.Pp 494.It [0addr] 495Empty lines are ignored. 496.Pp 497.It [0addr]# 498The 499.Dq # 500and the remainder of the line are ignored (treated as a comment), with 501the single exception that if the first two characters in the file are 502.Dq #n , 503the default output is suppressed. 504This is the same as specifying the 505.Fl n 506option on the command line. 507.El 508.Sh ENVIRONMENT 509The 510.Ev COLUMNS , LANG , LC_ALL , LC_CTYPE 511and 512.Ev LC_COLLATE 513environment variables affect the execution of 514.Nm 515as described in 516.Xr environ 7 . 517.Sh DIAGNOSTICS 518.Ex -std 519.Sh SEE ALSO 520.Xr awk 1 , 521.Xr ed 1 , 522.Xr grep 1 , 523.Xr regex 3 , 524.Xr re_format 7 525.Sh STANDARDS 526The 527.Nm 528utility is expected to be a superset of the 529.St -p1003.2 530specification. 531.Pp 532The 533.Fl i 534option is a non-standard 535.Fx 536extension and may not be available on other operating systems. 537.Sh HISTORY 538A 539.Nm 540command, written by L. E. McMahon, appeared in 541.At v7 . 542.Sh AUTHORS 543.An "Diomidis D. Spinellis" Aq dds@FreeBSD.org 544