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NAMEsed — stream text editor SYNOPSISsed
[-n]
script
[file]... sed
[-n]
[-e
script]...
[-f
script_file]...
[file]... DESCRIPTIONsed
copies the named text
files
(standard input default) to the standard output,
edited according to a script containing up to 100 commands.
Only complete input lines are processed.
Any input text at the end of a file that is not terminated
by a new-line character is ignored. Optionssed
recognizes the following options:
- -f script_file
Take script from file
script_file. - -e script
Edit according to
script.
If there is just one
-e
option and no
-f
options, the flag
-e
can be omitted. - -n
Suppress the default output.
sed
interprets all
-e script
and
-f script_file
arguments in the order given.
Use caution, if mixing
-e
and
-f
options, to avoid unpredictable or incorrect results. Command ScriptsA script consists of editor 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. Command AddressesAn
address
is either a decimal number that counts
input lines cumulatively across files, a
$
which addresses the last line of input,
or a context address; that is, 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 character 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).
Thereafter the process is repeated, looking again for the
first address.
sed
supports Basic Regular Expression syntax (see
regexp(5)). Editing commands can also be applied to only non-selected pattern spaces
by use of the negation function
!
(described below). Command FunctionsIn the following list of functions,
the maximum number of permissible addresses for each function
is indicated in parentheses.
Other function elements are interpreted as follows:
- text
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 can be used to protect initial blanks and tabs
against the stripping that is done on every script line. - rfile
Must terminate the command line, and must be preceded by exactly one blank. - 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.
sed
recognizes the following functions: - (1)a\
- text
Append.
Place
text
on the output before reading next input line. - (2)b label
Branch to the
:
command bearing
label.
If no
label
is specified, 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 pattern space and start the next cycle. - (2)D
Delete initial segment of pattern space through first new-line
and start the next cycle. - (2)g
Replace contents of the pattern space with contents of the hold space. - (2)G
Append contents of hold space to the pattern space. - (2)h
Replace contents of the hold space with 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 three-digit octal number format
(with a preceding backslash),
and long lines are folded. - (2)n
Copy the pattern space to the standard output
if the default output has not been suppressed (by the
-n
option on the command line or the
#n
command in the
script
file).
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. - (1)r rfile
Read contents of
rfile
and place on output before reading the next input line. - (2)s/regular expression/replacement/flags
Substitute
replacement
string for instances of
regular expression
in the pattern space.
Any character can be used instead of
/.
For a fuller description see
ed(1).
flags
is zero or more of:
- n
n=1-2048
(LINE_MAX).
Substitute for just the
nth
occurrence of
regular expression
in the pattern space. - g
Global.
Substitute for all non-overlapping instances of
regular expression
rather than just the first one. - p
Print the pattern space if a replacement was made
and the default output has been suppressed (by the
-n
option on the command line or the
#n
command in the
script
file). Under the
UNIX
Standard
environment (see
standards(5)),
the pattern space is printed twice, if the
-n
option is not specified on the command line. - 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. Any character other than backslash or
newline can be used instead of slash to delimit the
two strings. If a backslash character is immediately
followed by another backslash character in
string1
or
string2,
the two backslash characters will be handled
as a single literal backslash character. The delimiter itself can be used as a literal character in
string1
and
string2
if it is preceded by a backslash.
The only exception is character "n" as the delimiter,
because backslash-n, "\n", will be interpreted as a newline. The meaning of a backslash is undefined if it is followed by any
character that is not "n", a backslash, or the delimiter character. - (2)! function
Don't.
Apply the
function
(or group, if
function
is
{)
only to lines
not
selected by the address or addresses. - (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.
The syntax is:
- (0)
An empty command is ignored. - (0)#
If a
#
appears as the first character on the first line of a script file,
that entire line is treated as a comment with one exception:
If the character after the
#
is an
n,
the default output is suppressed.
The rest of the line after
#n
is also ignored.
A script file must contain at least one non-comment line.
EXTERNAL INFLUENCESFor information about the UNIX Standard environment, see
standards(5). Environment VariablesLANG
provides a default value for the internationalization variables that are unset
or null. If
LANG
is unset or null, the default value of "C" (see
lang(5))
is used. If any of the internationalization variables contains an invalid setting,
sed
will behave as if all internationalization variables are set to "C".
See
environ(5). LC_ALL
If set to a non-empty string value, overrides the values of all the other
internationalization variables. LC_CTYPE
determines the interpretation of text as single and/or
multi-byte characters, the classification of characters as printable,
and the characters matched by character class expressions in regular
expressions. LC_MESSAGES
determines the locale that should be used to affect the format and contents
of diagnostic messages written to standard error and informative messages
written to standard output. NLSPATH
determines the location of message catalogues for the processing of
LC_MESSAGES. International Code Set SupportSingle- and multi-byte character code sets are supported. EXAMPLESMake a simple substitution in a file from the command line
or from a shell script, changing
abc
to
xyz:
sed 's/abc/xyz/' file1 >file1.out Same as above but use shell or environment variables
var1
and
var2
in search and replacement strings:
sed "s/$var1/$var2/" file1 >file1.out or
sed 's/'$var1'/'$var2'/' file1 >file1.out Multiple substitutions in a single command:
sed -e 's/abc/xyz/' -e 's/lmn/rst/' file1 >file1.out or
sed -e 's/abc/xyz/' \
-e 's/lmn/rst/' \
file1 >file1.out WARNINGSsed
limits command scripts to a total of not more than 100 commands. The hold space is limited to 8192 characters. sed
processes only text files.
See the glossary for a definition of text files and their limitations. AUTHORsed
was developed by OSF and HP. STANDARDS CONFORMANCEsed: SVID2, SVID3, XPG2, XPG3, XPG4, POSIX.2 |
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