SED(1) SysV SED(1)
NAME
sed - stream editor
SYNOPSIS
sed [ -n ] [ -e script ] [ -f sfile ] [ files ]
DESCRIPTION
The sed command copies the named files (standard input default) to the
standard output, edited according to a script of commands.
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.
Some of the commands use a hold space to save all or part of the pattern
space for subsequent retrieval.
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, i.e., a /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 newline embedded in the pattern
space.
⊕ A period . matches any character except the terminal newline of 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 ! (See the Functions section below).
OPTIONS
-e script
Edit according to script. If there is just one -e option and no -f
options, the flag -e may be omitted.
-f sfile
Take the script from file sfile; these options accumulate.
-n Suppress the default output.
FUNCTIONS
In the following list of functions the maximum number of permissible
addresses for each function is indicated in parentheses.
The text argument 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. The rfile or wfile argument 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 newline. 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)l List the pattern space on the standard output in an
unambiguous form. Non-printing characters are spelled in
two-digit ASCII and long lines are folded.
(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:
n n= 1 - 512. Substitute for just the n th
occurrence of the regular expression.
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 colon (:) 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 Don't. Apply the function (or group, if function is a
left brace ({) 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 right
brace (}) only when the pattern space is selected.
(0) An empty command is ignored.
(0)# If a pound sign (#) appears as the first character on the
first line of a script file, then that entire line is
treated as a comment, with one exception. If the
character after the pound sign is an 'n', then the default
output will be suppressed. The rest of the line after #n
is also ignored. A script file must contain at least one
non-comment line.
FILES
/lib/chrclass/*
NOTE
For information on the sed user-settable character classes, see
chrtbl(1M), ctype(3C), and environ(5).
SEE ALSO
awk(1), ed(1), grep(1), chrtbl(1M), ctype(3C), environ(5).