SED(1) DOMAIN/IX SYS5 SED(1)
NAME
sed - stream editor
USAGE
sed [ -n ] [ -e script ] [ -f sfile ] [ files ]
DESCRIPTION
Sed 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.
OPTIONS
-e script Specify script as a set of commands with which to
edit the named files. If there is just one -e
option and no -f options, the flag -e may be omit-
ted.
-f sfile Cause the script to be taken from file sfile.
This option accumulates.
-n Suppress the default output.
ADDRESSES
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) with the modifications
explained in the following paragraphs.
In a context address, the construction \?regular expres-
sion?, 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 expres-
sion is abcxdef.
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The escape sequence \n matches a newline embedded in the
pattern space.
A period (.) matches any character except the terminal new-
line 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.) Consequently, the process is repeated, looking
again for the first address.
You can apply editing commands to nonselected pattern spaces
only by using the negation function (!).
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 a backslash (\) to hide the newline.
Backslashes in text are treated like backslashes in the
replacement string of an s command, and may be used to pro-
tect 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 colon (:) command bearing the label.
If label is empty, branch to the end of the
script.
(2)c\
text Change. Delete the pattern space. With a 0 or 1
address or at the end of a 2-address range, place
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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 pat-
tern space.
(2)h Replace the contents of the hold space by the con-
tents 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. Nonprinting 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
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the regular expression in the pattern space. Any
character may be used instead of a slash (/). For
a more complete description, refer to ed(1).
Flags is zero or more of:
n n=1 through 512. Substitute for just
the nth occurrence of the regular
expression.
g Global. Substitute for all nonoverlap-
ping 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 execu-
tion 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 characters in
string2. The lengths of string1 and string2 must
be equal.
(2)! function
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 to
which b and t commands branch.
(1)= Place the current line number on the standard out-
put as a line.
(2){ Execute the following commands through a matching
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} only when the pattern space is selected.
(0) An empty command is ignored.
(0)# If a pound sign (#) appears as the first character
on any line of a script file, then that entire
line is treated as a comment, with one exception.
On the first line of the script only, if the char-
acter 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 noncomment line.
RELATED INFORMATION
awk(1), ed(1), grep(1).
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