sed(1) UNIX System V(Essential Utilities) sed(1)
NAME
sed - stream editor
SYNOPSIS
sed [-n] [-e script] [-f sfile] [file ...]
DESCRIPTION
sed copies the named file (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 options, the flag -e may be
omitted. The -n option suppresses 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.
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 new-line 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
address. (If the second address is a number less than or
equal to the line number selected by the first address, only
the line corresponding to the first address is selected.)
Thereafter the process is repeated, looking again for the
first address.
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sed(1) UNIX System V(Essential Utilities) sed(1)
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.
The text argument 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 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. 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)l List the pattern space on the standard output in an unambiguous
form. Non-printable characters are displayed in octal notation
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.
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sed(1) UNIX System V(Essential Utilities) sed(1)
(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 fuller description see ed(1). flags is
zero or more of:
n n= 1 - 512. Substitute for just the nth 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 : 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. The first
occurrence of w will cause wfile to be cleared. Subsequent
invocations of w will append. Each time the sed command is
used, wfile is overwritten.
(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. string1 and
string2 must have the same number of characters.
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sed(1) UNIX System V(Essential Utilities) sed(1)
(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)# If a # appears as the first character on a line of a script
file, then that entire line is treated as a comment, with one
exception: if a # appears on the first line and the character
after the # 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.
SEE ALSO
awk(1), ed(1), grep(1).
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