Ubuntu Manpage: sed - stream editor for filtering and transforming text

NAME

       sed - stream editor for filtering and transforming text

SYNOPSIS

       sed [-V] [--version] [--help] [-n] [--quiet] [--silent]
           [-l N] [--line-length=N] [-u] [--unbuffered]
           [-E] [-r] [--regexp-extended]
           [-e script] [--expression=script]
           [-f script-file] [--file=script-file]
           [script-if-no-other-script]
           [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

--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>.

Packaged by Debian Copyright © 2022 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.

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 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

       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

       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

       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 disabled 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>.