sed(1)sed(1)Namesed - stream text editor
Syntaxsed [-n] [-e script] [-f sfile] [file...]
Description
The command copies the named files (standard input default) to the
standard output, edited according to a script of commands. The -f
option causes the script to be taken from file sfile; these options
accumulate. If there is just one -e option and no -f's, the flag -e
may be omitted. The -n option suppresses the default output; inclusion
in the script of a comment command of the form also suppresses the
default output. (See the description of the `#' command.)
A script consists of editing commands of the following form:
[address [, address] ] function [arguments]
Nominally, there is one command per line; but commands can be concate‐
nated on a line by being separated with semicolons
In normal operation cyclically copies a line of input into a pattern
space (unless there is something left after a `D' command), applies in
sequence all commands whose addresses select that pattern space, and at
the end of the script copies the pattern space to the standard output
(except under -n) and deletes the pattern space.
An address is either a decimal number that counts input lines cumula‐
tively across files, a `$' that addresses the last line of input, or a
context address, `/regular expression/', in the style of ed(1) modified
thus:
· In a context address, the construction \?regular expression?,
where ? is any character, is identical to regular expression.
Note that in the context address \xabc\xdefx, the second x
stands for itself, so that the regular expression is abcxdef.
· The escape sequence `\n' matches a new line embedded in the
pattern space.
· A command line with no addresses selects every pattern space.
· A command line with one address selects each pattern space that
matches the address.
· A command line with two addresses selects the inclusive range
from the first pattern space that matches the first address
through the next pattern space that matches the second. (If
the second address is a number less than or equal to the line
number first selected, only one line is selected.) Thereafter
the process is repeated, looking again for the first address.
Editing commands can be applied only to non-selected pattern spaces by
use of the negation function `!' (below).
In the following list of functions the maximum number of permissible
addresses for each function is indicated in parentheses.
An argument denoted text consists of one or more lines, all but the
last of which end with `\' to hide the new line. Backslashes in text
are treated like backslashes in the replacement string of an `s' com‐
mand, and may be used to protect initial blanks and tabs against the
stripping that is done on every script line.
An argument denoted rfile or wfile must terminate the command line and
must be preceded by exactly one blank. Each wfile is created before
processing begins. There can be at most 10 distinct wfile arguments.
(1)a\
text
Append. Place text on the output before reading the next input
line.
(2)b label
Branch to the `:' command bearing the label. If label is
empty, branch to the end of the script.
(2)c\
text
Change. Delete the pattern space. With 0 or 1 address or at
the end of a 2-address range, place text on the output. Start
the next cycle.
(2)d Delete the pattern space. Start the next cycle.
(2)D Delete the initial segment of the pattern space through the
first new line. Start the next cycle.
(2)g Replace the contents of the pattern space by the contents of
the hold space.
(2)G Append the contents of the hold space to the pattern space.
(2)h Replace the contents of the hold space by the contents of the
pattern space.
(2)H Append the contents of the pattern space to the hold space.
(1)i\
text
Insert. Place text on the standard output.
(2)n Copy the pattern space to the standard output. Replace the
pattern space with the next line of input.
(2)N Append the next line of input to the pattern space with an
embedded new line. (The current line number changes.)
(2)p Print. Copy the pattern space to the standard output.
(2)P Copy the initial segment of the pattern space through the first
new line to the standard output.
(1)q Quit. Branch to the end of the script. Do not start a new
cycle.
(2)r rfile
Read the contents of rfile. Place them on the output before
reading the next input line.
(2)s/regular expression/replacement/flags
Substitute the replacement string for instances of the regular
expression in the pattern space. Any character may be used
instead of `/'. For a more complete description see The flags
is zero or more of
g Global. Substitute for all nonoverlapping instances of
the regular expression rather than just the first one.
p Print the pattern space if a replacement was made.
w wfile Write. Append the pattern space to wfile if a replace‐
ment was made.
(2)t label
Test. Branch to the `:' command bearing the label if any sub‐
stitutions have been made since the most recent reading of an
input line or execution of a `t'. If label is empty, branch to
the end of the script.
(2)w wfile
Write. Append the pattern space to wfile.
(2)x Exchange the contents of the pattern and hold spaces.
(2)y/string1/string2/
Transform. Replace all occurrences of characters in string1
with the corresponding character in string2. The lengths of
string1 and string2 must be equal.
(2)! function
Don't. Apply the function (or group, if function is `{') only
to lines not selected by the address(es).
(0): label
This command does nothing; it bears a label for `b' and `t'
commands to branch to.
(1)= Place the current line number on the standard output as a line.
(2){ Execute the following commands through a matching `}' only when
the pattern space is selected.
(0) An empty command is ignored.
(0)# With one exception, any line whose first nonblank character is
a number sign is a comment and is ignored. The exception is
that if the first such line encountered contains only the num‐
ber sign followed by the letter `n' the default output is sup‐
pressed as if the -n option were in force.
Options-e 'command;command...'
Uses command;command... as the editing script. If no -f
option is given, the -e keyword can be omitted. For example,
the following two command are functionally identical:
% sed-e 's/DIGITAL/Digital/g' summary > summary.out
% sed 's/DIGITAL/Digital/g' summary > summary.out
-f sfile
Uses specified file as input file of commands to be executed.
Can be used with -e option to apply both explicit commands and
a separate script file.
-n Suppresses all normal output, writing only lines explicitly
written by the `p' or `P' commands or by an `s' command with
the `p' flag.
See Alsoawk(1), ed(1), grep(1), lex(1)sed(1)
