sed(1) — Linux manual page

NAME | SYNOPSIS | DESCRIPTION | COMMAND SYNOPSIS | REGULAR EXPRESSIONS | BUGS | AUTHOR | COPYRIGHT | SEE ALSO | COLOPHON

SED(1)                        User Commands                       SED(1)

NAME         top

       sed - stream editor for filtering and transforming text

SYNOPSIS         top

       sed [OPTION]... {script-only-if-no-other-script} [input-file]...

DESCRIPTION         top

       Sed is a stream editor.  A stream editor is used to perform basic
       text transformations on an input stream (a file or input from a
       pipeline).  While in some ways similar to an editor which permits
       scripted edits (such as ed), sed works by making only one pass
       over the input(s), and is consequently more efficient.  But it is
       sed's ability to filter text in a pipeline which particularly
       distinguishes it from other types of editors.

       -n, --quiet, --silent

              suppress automatic printing of pattern space

       --debug

              annotate program execution

       -e script, --expression=script

              add the script to the commands to be executed

       -f script-file, --file=script-file

              add the contents of script-file to the commands to be
              executed

       --follow-symlinks

              follow symlinks when processing in place

       -i[SUFFIX], --in-place[=SUFFIX]

              edit files in place (makes backup if SUFFIX supplied)

       -l N, --line-length=N

              specify the desired line-wrap length for the `l' command

       --posix

              disable all GNU extensions.

       -E, -r, --regexp-extended

              use extended regular expressions in the script (for
              portability use POSIX -E).

       -s, --separate

              consider files as separate rather than as a single,
              continuous long stream.

       --sandbox

              operate in sandbox mode (disable e/r/w commands).

       -u, --unbuffered

              load minimal amounts of data from the input files and
              flush the output buffers more often

       -z, --null-data

              separate lines by NUL characters

       --help
              display this help and exit

       --version
              output version information and exit

       If no -e, --expression, -f, or --file option is given, then the
       first non-option argument is taken as the sed script to
       interpret.  All remaining arguments are names of input files; if
       no input files are specified, then the standard input is read.

       GNU sed home page: <https://www.gnu.org/software/sed/>.  General
       help using GNU software: <https://www.gnu.org/gethelp/>.  E-mail
       bug reports to: <bug-sed@gnu.org>.

COMMAND SYNOPSIS         top

       This is just a brief synopsis of sed commands to serve as a
       reminder to those who already know sed; other documentation (such
       as the texinfo document) must be consulted for fuller
       descriptions.

   Zero-address ``commands''
       : label
              Label for b and t commands.

       #comment
              The comment extends until the next newline (or the end of
              a -e script fragment).

       }      The closing bracket of a { } block.

   Zero- or One- address commands
       =      Print the current line number.

       a \

       text   Append text, which has each embedded newline preceded by a
              backslash.

       i \

       text   Insert text, which has each embedded newline preceded by a
              backslash.

       q [exit-code]
              Immediately quit the sed script without processing any
              more input, except that if auto-print is not disabled the
              current pattern space will be printed.  The exit code
              argument is a GNU extension.

       Q [exit-code]
              Immediately quit the sed script without processing any
              more input.  This is a GNU extension.

       r filename
              Append text read from filename.

       R filename
              Append a line read from filename.  Each invocation of the
              command reads a line from the file.  This is a GNU
              extension.

   Commands which accept address ranges
       {      Begin a block of commands (end with a }).

       b label
              Branch to label; if label is omitted, branch to end of
              script.

       c \

       text   Replace the selected lines with text, which has each
              embedded newline preceded by a backslash.

       d      Delete pattern space.  Start next cycle.

       D      If pattern space contains no newline, start a normal new
              cycle as if the d command was issued.  Otherwise, delete
              text in the pattern space up to the first newline, and
              restart cycle with the resultant pattern space, without
              reading a new line of input.

       h H    Copy/append pattern space to hold space.

       g G    Copy/append hold space to pattern space.

       l      List out the current line in a ``visually unambiguous''
              form.

       l width
              List out the current line in a ``visually unambiguous''
              form, breaking it at width characters.  This is a GNU
              extension.

       n N    Read/append the next line of input into the pattern space.

       p      Print the current pattern space.

       P      Print up to the first embedded newline of the current
              pattern space.

       s/regexp/replacement/
              Attempt to match regexp against the pattern space.  If
              successful, replace that portion matched with replacement.
              The replacement may contain the special character & to
              refer to that portion of the pattern space which matched,
              and the special escapes \1 through \9 to refer to the
              corresponding matching sub-expressions in the regexp.

       t label
              If a s/// has done a successful substitution since the
              last input line was read and since the last t or T
              command, then branch to label; if label is omitted, branch
              to end of script.

       T label
              If no s/// has done a successful substitution since the
              last input line was read and since the last t or T
              command, then branch to label; if label is omitted, branch
              to end of script.  This is a GNU extension.

       w filename
              Write the current pattern space to filename.

       W filename
              Write the first line of the current pattern space to
              filename.  This is a GNU extension.

       x      Exchange the contents of the hold and pattern spaces.

       y/source/dest/
              Transliterate the characters in the pattern space which
              appear in source to the corresponding character in dest.

Addresses
       Sed commands can be given with no addresses, in which case the
       command will be executed for all input lines; with one address,
       in which case the command will only be executed for input lines
       which match that address; or with two addresses, in which case
       the command will be executed for all input lines which match the
       inclusive range of lines starting from the first address and
       continuing to the second address.  Three things to note about
       address ranges: the syntax is addr1,addr2 (i.e., the addresses
       are separated by a comma); the line which addr1 matched will
       always be accepted, even if addr2 selects an earlier line; and if
       addr2 is a regexp, it will not be tested against the line that
       addr1 matched.

       After the address (or address-range), and before the command, a !
       may be inserted, which specifies that the command shall only be
       executed if the address (or address-range) does not match.

       The following address types are supported:

       number Match only the specified line number (which increments
              cumulatively across files, unless the -s option is
              specified on the command line).

       first~step
              Match every step'th line starting with line first.  For
              example, ``sed -n 1~2p'' will print all the odd-numbered
              lines in the input stream, and the address 2~5 will match
              every fifth line, starting with the second.  first can be
              zero; in this case, sed operates as if it were equal to
              step.  (This is an extension.)

       $      Match the last line.

       /regexp/
              Match lines matching the regular expression regexp.
              Matching is performed on the current pattern space, which
              can be modified with commands such as ``s///''.

       \cregexpc
              Match lines matching the regular expression regexp.  The c
              may be any character.

       GNU sed also supports some special 2-address forms:

       0,addr2
              Start out in "matched first address" state, until addr2 is
              found.  This is similar to 1,addr2, except that if addr2
              matches the very first line of input the 0,addr2 form will
              be at the end of its range, whereas the 1,addr2 form will
              still be at the beginning of its range.  This works only
              when addr2 is a regular expression.

       addr1,+N
              Will match addr1 and the N lines following addr1.

       addr1,~N
              Will match addr1 and the lines following addr1 until the
              next line whose input line number is a multiple of N.

REGULAR EXPRESSIONS         top

       POSIX.2 BREs should be supported, but they aren't completely
       because of performance problems.  The \n sequence in a regular
       expression matches the newline character, and similarly for \a,
       \t, and other sequences.  The -E option switches to using
       extended regular expressions instead; it has been supported for
       years by GNU sed, and is now included in POSIX.

BUGS         top

       E-mail bug reports to bug-sed@gnu.org.  Also, please include the
       output of ``sed --version'' in the body of your report if at all
       possible.

AUTHOR         top

       Written by Jay Fenlason, Tom Lord, Ken Pizzini, Paolo Bonzini,
       Jim Meyering, and Assaf Gordon.

       This sed program was built with SELinux support.  SELinux is
       enabled on this system.

       GNU sed home page: <https://www.gnu.org/software/sed/>.  General
       help using GNU software: <https://www.gnu.org/gethelp/>.  E-mail
       bug reports to: <bug-sed@gnu.org>.

COPYRIGHT         top

       Copyright © 2020 Free Software Foundation, Inc.  License GPLv3+:
       GNU GPL version 3 or later <https://gnu.org/licenses/gpl.html>.
       This is free software: you are free to change and redistribute
       it.  There is NO WARRANTY, to the extent permitted by law.

SEE ALSO         top

       awk(1), ed(1), grep(1), tr(1), perlre(1), sed.info, any of
       various books on sed, the sed FAQ
       (http://sed.sf.net/grabbag/tutorials/sedfaq.txt),
       http://sed.sf.net/grabbag/.

       The full documentation for sed is maintained as a Texinfo manual.
       If the info and sed programs are properly installed at your site,
       the command

              info sed

       should give you access to the complete manual.

COLOPHON         top

       This page is part of the sed (stream-oriented editor) project.
       Information about the project can be found at 
       ⟨http://www.gnu.org/software/sed/⟩.  If you have a bug report for
       this manual page, send it to bug-sed@gnu.org.  This page was
       obtained from the tarball sed-4.8.tar.gz fetched from
       ⟨https://www.gnu.org/software/sed/⟩ on 2021-08-27.  If you
       discover any rendering problems in this HTML version of the page,
       or you believe there is a better or more up-to-date source for
       the page, or you have corrections or improvements to the
       information in this COLOPHON (which is not part of the original
       manual page), send a mail to man-pages@man7.org

sed 4.8                       January 2020                        SED(1)

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