Linux文本处理四剑客sed指令-man帮助手册

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 transforma‐
tions on an input stream (a file or input from a pipeline). While in some ways simi‐
lar 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 ar‐
gument 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 soft‐
ware: <https://www.gnu.org/gethelp/>. E-mail bug reports to: <[email protected]>.

COMMAND SYNOPSIS
This is just a brief synopsis of sed commands to serve as a reminder to those who al‐
ready 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 frag‐
ment).

} The closing bracket of a { } block.

Zero- or One- address commands
= Print the current line number.

text Append text, which has each embedded newline preceded by a backslash.

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.

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 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.

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 exe‐
cuted 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 ad‐
dress 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 ex‐
tension.)

$ 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 charac‐
ter.

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
sequence in a regular expression matches the newline character, and
similarly for a, , 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 [email protected]. 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 As‐
saf Gordon.

This sed program was built with SELinux support. SELinux is enabled on this system.

GNU sed home page: <https://www.gnu.org/software/sed/>. General help using GNU soft‐
ware: <https://www.gnu.org/gethelp/>. E-mail bug reports to: <[email protected]>.

COPYRIGHT
Copyright ? 2020 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 WAR‐
RANTY, 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/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 4.8 January 2020 SED(1)