SED(C) XENIX System V SED(C)
Name
sed - Invokes the stream editor.
Syntax
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.
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(C) modified as follows:
- 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
Page 1 (printed 8/7/87)
SED(C) XENIX System V SED(C)
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 nonselected 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 backslashes to hide the newlines.
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 Appends text, placing it on the output before
reading the next input line.
(2)b label
Branches to the : command bearing the label. If
label is empty, branches to the end of the script.
(2)c\
text Changes text by deleting the pattern space and
then appending text. With 0 or 1 address or at the
end of a 2-address range, places text on the
output and starts the next cycle.
(2)d Deletes the pattern space and starts the next
cycle.
(2)D Deletes the initial segment of the pattern space
through the first newline and starts the next
cycle.
(2)g Replaces the contents of the pattern space with
the contents of the hold space.
(2)G Appends the contents of the hold space to the
pattern space.
(2)h Replaces the contents of the hold space with the
contents of the pattern space.
Page 2 (printed 8/7/87)
SED(C) XENIX System V SED(C)
(2)H Appends the contents of the pattern space to the
hold space.
(1)i\
text Insert. Places text on the standard output.
(2)l Lists the pattern space on the standard output
with nonprinting characters spelled in two-digit
ASCII and long lines folded.
(2)n Copies the pattern space to the standard output.
Replaces the pattern space with the next line of
input.
(2)N Appends the next line of input to the pattern
space with an embedded newline. (The current line
number changes.)
(2)p Prints (copies) the pattern space on the standard
output.
(2)P Prints (copies) the initial segment of the pattern
space through the first newline to the standard
output.
(1)q Quits sed by branching to the end of the script.
No new cycle is started.
(2)r rfile
Reads the contents of rfile and places them on the
output before reading the next input line.
(2)s/regular expression/replacement/flags
Substitutes the replacement string for instances
of the regular expression in the pattern space.
Any character may be used instead of /. For a
more detailed description, see ed(C). Flags is
zero or more of:
g Globally substitutes for all nonoverlapping
instances of the regular expression rather
than just the first one.
p Prints the pattern space if a replacement was
made.
w wfile
Writes the pattern space to wfile if a
replacement was made.
(2)t label
Branches to the colon (:) command bearing label if
Page 3 (printed 8/7/87)
SED(C) XENIX System V SED(C)
any substitutions have been made since the most
recent reading of an input line or execution of a
t command. If label is empty, t branches to the
end of the script.
(2)w wfile
Writes the pattern space to wfile.
(2)x Exchanges the contents of the pattern and hold
spaces.
(2)y/string1/string2/
Replaces all occurrences of characters in string1
with the corresponding characters in string2. The
lengths of string1 and string2 must be equal.
(2)! function
Applies 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)= Places the current line number on the standard
output as a line.
(2){ Executes the following commands through a matching
} only when the pattern space is selected.
(0) An empty command is ignored.
See Also
awk(C), ed(C), grep(C)
Notes
This command is explained in detail in XENIX Text Processing
Guide.
Page 4 (printed 8/7/87)