SED(1) User Commands SED(1)NAMEsed - manual page for sed version 4.0.7
SYNOPSISsed [OPTION]... {script-only-if-no-other-script} [input-
file]...
DESCRIPTION
Sed is a stream editor. A stream editor is used to per-
form 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
-i[suffix], --in-place[=suffix]
edit files in place (makes backup if extension sup-
plied)
-l N, --line-length=N
specify the desired line-wrap length for the `l'
command
-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
-V, --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 documenta-
tion (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 pre-
ceded by a backslash.
i \
text Insert text, which has each embedded newline pre-
ceded 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 pat-
tern space. Start next cycle, but skip reading
from the input if there is still data in the pat-
tern 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 unambigu-
ous'' 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 cur-
rent 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 spe-
cial 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 charac-
ter 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 sec-
ond address. Three things to note about address ranges:
the syntax is addr1,addr2 (i.e., the addresses are sepa-
rated 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 com-
mand, a ! may be inserted, which specifies that the com-
mand 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 com-
pletely 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 (C) 2003 Free Software Foundation, Inc.
This is free software; see the source for copying condi-
tions. There is NO warranty; not even for MERCHANTABILITY
or FITNESS FOR A PARTICULAR PURPOSE, to the extent permit-
ted by law.
SEE ALSOawk(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.html), 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 4.0.7 April 2003 SED(1)
