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'' somewhere 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 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 exten‐
	      sion.

   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      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 exten‐
	      sion.

       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.

       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 possible.

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  FIT‐
       NESS 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'' somewhere 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/grab‐
       bag/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)