SED("1") manual page
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sed - stream editor for filtering and transforming text
sed
[OPTION]... {script-only-if-no-other-script} [input-file]...
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), works by making
only one pass over the input(s), and is consequently more efficient. But
it is ’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 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.
This is just a brief synopsis of commands to serve
as a reminder to those who already know ; 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
- Immediately quit the 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 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 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 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.
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.
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 © 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 PARTICULAR PURPOSE,
to the extent permitted by law.
awk(1)
, ed(1)
, grep(1)
, tr(1)
, perlre(1)
,
sed.info, any of various books on , the FAQ (http://sed.sf.net/grabbag/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.
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