SED(1) SED(1)
NAME
sed - stream editor
SYNOPSIS
sed [ -n ] [ -e script ] [ -f sfile ] [ file ] ...
DESCRIPTION
Sed 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 sup-
presses the default output.
A script consists of editing commands, one per line, of the
following form:
[address [, address] ] function [arguments]
In normal operation sed 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 cumulatively across files, a `$' that addresses the
last line of input, or a context address, `/regular expres-
sion/', in the style of ed(1) modified thus:
The escape sequence `\n' matches a newline 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 sec-
ond. (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).
SED(1) SED(1)
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 newline.
Backslashes in text are treated like backslashes in the
replacement string of an `s' command, 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 com-
mand 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 newline. Start the next cycle.
(2)g Replace the contents of the pattern space by the con-
tents 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.
SED(1) SED(1)
(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 newline. (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 newline 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 fuller description
see ed(1). 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
replacement was made.
(2)t label
Test. Branch to the `:' command bearing the label if
any substitutions 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
SED(1) SED(1)
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.
SEE ALSO
ed(1), grep(1), awk(1), lex(1), cut(1), split(1)