SED(1) | General Commands Manual | SED(1) |
sed
—
sed |
[-aEnru ]
[-i [extension]]
command [file ...] |
sed |
[-aEnru ] [-e
command] [-f
command_file]
[-i [extension]]
[file ...] |
sed
utility reads the specified files, or the
standard input if no files are specified, modifying the input as specified by
a list of commands. The input is then written to the standard output.
A single command may be specified as the first argument to
sed
. Multiple commands may be specified separated by
newlines or semicolons, or by using the -e
or
-f
options. All commands are applied to the input in
the order they are specified regardless of their origin.
The options are as follows:
-a
w
function
or flag are created (or truncated) before any processing begins, by
default. The -a
option causes
sed
to delay opening each file until a command
containing the related w
function or flag is
applied to a line of input.-E
-e
command-f
command_file-i
[extension]-i
mode, the hold space, line numbers, and ranges
are reset between files.-r
-E
, for compatibility with GNU
sed.-n
-n
option suppresses this behavior.-u
The form of a sed
command is as
follows:
[address[,address]]function[arguments]
Whitespace may be inserted before the first address and the function portions of the command.
Normally, sed
cyclically copies a line of
input, not including its terminating newline character, into a
pattern space, (unless there is something left after a
D
function), applies all of the commands with
addresses that select that pattern space, copies the pattern space to the
standard output, appending a newline, and deletes the pattern space.
Some of the functions use a hold space to save all or part of the pattern space for subsequent retrieval.
$
’) that addresses the last line of
input, or a context address, which is a regular expression preceded and
followed by a delimiter. The delimiter can be any character except a newline
or a backslash. Unless it is a slash, the opening delimiter needs to be
escaped with a backslash.
A command line with no addresses selects every pattern space.
A command line with one address selects all of the pattern spaces that match 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 that line is
selected.) Starting at the first line following the selected range,
sed
starts looking again for the first address.
Editing commands can be applied to non-selected pattern spaces by
use of the exclamation character (‘!
’)
function.
sed
regular expressions are basic regular
expressions (BREs). Extended regular expressions are supported using the
-E
and -r
options. See
re_format(7) for more information on
regular expressions. In addition, sed
has the
following two additions to BREs:
One special feature of sed
regular
expressions is that they can default to the last regular expression used. If
a regular expression is empty, i.e., just the delimiter characters are
specified, the last regular expression encountered is used instead. The last
regular expression is defined as the last regular expression used as part of
an address or substitute command, and at run-time, not compile-time. For
example, the command “/abc/s//XXX/” will substitute
“XXX” for the pattern “abc”.
The argument text consists of one or more lines. To embed a newline in the text, precede it with a backslash. Other backslashes in text are deleted and the following character taken literally.
The r
and w
functions, as well as the w
flag to the
s
function, take a file
parameter, which should be separated from the function or flag by
whitespace. Files are created (or their contents truncated) before any input
processing begins.
The b
, r
,
s
, t
,
w
, y
, and
:
functions all accept additional arguments. The
synopses below indicate which arguments have to be separated from the
function letters by whitespace characters.
The a
, c
,
i
, r
, and
w
functions cannot be followed by another command
separated with a semicolon. The text and
file arguments may contain semicolon characters.
Functions can be combined to form a function
list, a list of sed
functions each followed by a
newline, as follows:
{ function function ... function }
The braces can be preceded and followed by whitespace. The functions can be preceded by whitespace as well.
Functions and function lists may be preceded by an exclamation mark, in which case they are applied only to lines that are not selected by the addresses.
a
\
N
function or by beginning a new cycle.b
[label]:
function with the specified
label. If the label is not specified, branch to the
end of the script.c
\
d
D
g
G
h
H
i
\
l
Non-printable characters are written as three-digit octal
numbers (with a preceding backslash) for each byte in the character
(most significant byte first). Long lines are folded, with the point of
folding indicated by displaying a backslash followed by a newline. The
end of each line is marked with a
‘$
’.
n
N
p
P
q
r
files
/RE/replacement/flagsAn ampersand (‘&
’)
appearing in the replacement is replaced by the string matching the
regular expression. The string
‘\#
’, where
‘#
’ is a digit, is replaced by the
text matched by the corresponding backreference expression (see
re_format(7)).
All other instances of a backslash will print the literal
character following it. Using a backslash before any other character
other than ‘&
’,
‘\
’, digit, newline (ascii 0x0a),
and the delimiter is unspecified and might not be portable to other
implementations of sed
.
The value of flags in the substitute function is zero or more of the following:
1
...
9
.g
p
w
filet
[label]:
function bearing the
label if any substitutions have been made since the
most recent reading of an input line or execution of a
t
function. If no label is specified, branch to
the end of the script.w
filex
y
/string1/string2/Within string1 and string2, a backslash followed by another backslash is replaced by a single backslash, a backslash followed by an ‘n’ is replaced by a newline character, and a backslash followed by the delimiting character is replaced by that character, causing it to be treated literally, with the exception of the ‘n’ character, which will still be treated like a newline character. It is an error for a backslash to not be followed by another backslash, ‘n’, or the delimiting character, or for string1 to contain repeating characters.
:
labelb
and t
commands
may branch.=
#
#
’ and the remainder of the
line are ignored (treated as a comment), with the single exception that if
the first two characters in the file are
‘#n
’, the default output is
suppressed. This is the same as specifying the -n
option on the command line.COLUMNS
l
function is formatted to the given width in columns. Otherwise,
sed
defaults to the terminal width, or 80 columns
if the output is not a terminal.sed
utility exits 0 on success,
and >0 if an error occurs.
sed
utility is compliant with the
IEEE Std 1003.1-2008 (“POSIX.1”)
specification.
The flags [-aEiru
] are extensions to that
specification.
Following the b
,
t
, or :
commands with a
semicolon and another command is an extension to the specification.
The use of newlines to separate multiple commands on the command
line is non-portable; the use of newlines to separate multiple commands
within a command file (-f
command_file) is portable.
sed
command appeared in
Version 7 AT&T UNIX.December 10, 2018 | OpenBSD-current |