SED(1)                            User Commands                           SED(1)



NAME
       sed - stream editor for filtering and transforming text

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

DESCRIPTION
       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

       -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 extension supplied)

       -l N, --line-length=N

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

       --posix

              disable all GNU extensions.

       -r, --regexp-extended

              use extended regular expressions in the script.

       -s, --separate

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

       -u, --unbuffered

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

       --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 remain‐
       ing arguments are names of input files; if no input files are  specified,
       then the standard input is read.

       GNU  sed  home  page:  <http://www.gnu.org/software/sed/>.   General help
       using GNU software: <http://www.gnu.org/gethelp/>.   E-mail  bug  reports
       to:  <bug-gnu-utils@gnu.org>.   Be sure to include the word ``sed'' some‐
       where in the ``Subject:'' field.

COMMAND SYNOPSIS
       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 doc‐
       ument) 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 back‐
              slash.

       i \

       text   Insert text, which has each embedded newline preceded by  a  back‐
              slash.

       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 new‐
              line preceded by a backslash.

       d      Delete pattern space.  Start next cycle.
       D      Delete up to the first embedded  newline  in  the  pattern  space.
              Start  next  cycle,  but  skip  reading from the input if there is
              still data in the pattern space.

       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  reg‐
       exp, 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.

       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.

       \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
       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.

BUGS
       E-mail  bug  reports  to  bonzini@gnu.org.   Be  sure to include the word
       ``sed'' somewhere in the ``Subject:'' field.  Also,  please  include  the
       output  of  ``sed --version'' in the body of your report if at all possi‐
       ble.

COPYRIGHT
       Copyright © 2009 Free Software Foundation, Inc.
       This is free software; see the source for copying conditions.   There  is
       NO  warranty;  not  even  for MERCHANTABILITY or FITNESS FOR A PARTICULAR
       PURPOSE, to the extent permitted by law.

       GNU sed  home  page:  <http://www.gnu.org/software/sed/>.   General  help
       using  GNU  software:  <http://www.gnu.org/gethelp/>.  E-mail bug reports
       to: <bug-gnu-utils@gnu.org>.  Be sure to include the word  ``sed''  some‐
       where in the ``Subject:'' field.

SEE ALSO
       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.



sed 4.2.1                         December 2010                           SED(1)