sed

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
       remaining  arguments  are  names  of input files; if no input files are
       specified, then the standard input is read.

       GNU sed home page:  .   General  help
       using  GNU software: .  E-mail bug reports
       to: .  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
       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 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  com‐
              mand 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.

       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.

       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      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.

       x      Exchange the contents of the hold and pattern spaces.

       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 success‐
              ful,  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.

       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.

       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 exe‐
       cuted 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.

       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:  .   General  help
       using  GNU software: .  E-mail bug reports
       to: .  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/sed‐
       faq.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 com‐
       mand

              info sed

       should give you access to the complete manual.



sed version 4.2.1                  June 2009                            SED(1)