SED(1) General Commands Manual SED(1)
NAME
sed - stream editor
SYNOPSIS
sed [-egn] [-f script_file] [edit_script] [file]
OPTIONS
-e Accept multiple commands commands on the commands line
-f The following argument contains the edit script
-g Set the global flag on all substitute commands
-n Only output selected lines
EXAMPLES
sed -f script <file # Run a sed script on file
sed '/pig/s//hog/g' <file
# Replace pig by hog in the file
DESCRIPTION
Sed is a stream editor. It takes an edit script either from its argument or a file, and performs an edit session on a named file or stdin,
producing output on stdout.
SEE ALSO
cgrep(1), fgrep(1), grep(1), awk(9).
SED(1)
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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 pipe-
line). 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.
E-mail bug reports to: bonzini@gnu.org . 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 tex-
info 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 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.
Q Immediately quit the sed script without processing any more input.
r filename
Append text read from filename.
R filename
Append a line read from filename.
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.
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.
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.
w filename
Write the current pattern space to filename.
W filename
Write the first line of the current pattern space to filename.
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. (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.
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
sequence in a regular expression
matches the newline character, and similarly for a, , 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 (C) 2003 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 PARTICU-
LAR PURPOSE, to the extent permitted by law.
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
command
info sed
should give you access to the complete manual.
sed version 4.1.5 July 2010 SED(1)