Command Summary for sed (sed & awk, Second Edition)

From 72cc9641f80b6981cc97fd66feb8d5842ea5ed03 Mon Sep 17 00:00:00 2001 From: Denis Vlasenko Date: Tue, 13 Nov 2007 17:13:31 +0000 Subject: add sed mini-doc --- editors/sed_summary.htm | 220 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 220 insertions(+) create mode 100644 editors/sed_summary.htm (limited to 'editors/sed_summary.htm') diff --git a/editors/sed_summary.htm b/editors/sed_summary.htm new file mode 100644 index 000000000..4ac9b16f6 --- /dev/null +++ b/editors/sed_summary.htm @@ -0,0 +1,220 @@ + + +Command Summary for sed (sed & awk, Second Edition) + + + + +

Command Summary for sed

+ +

: :label

Label a line in the script for the transfer of control by +b or t. +label may contain up to seven characters. +(The POSIX standard says that an implementation can allow longer +labels if it wishes to. GNU sed allows labels to be of any length.) +

= [address]=

Write to standard output the line number of addressed line.

a [address]a\

text

+ +

Append text +following each line matched by address. If +text goes over more than one line, newlines +must be "hidden" by preceding them with a backslash. The +text will be terminated by the first +newline that is not hidden in this way. The +text is not available in the pattern space +and subsequent commands cannot be applied to it. The results of this +command are sent to standard output when the list of editing commands +is finished, regardless of what happens to the current line in the +pattern space.

b [address1[,address2]]b[label]

Transfer control unconditionally (branch) to +:label elsewhere in +script. That is, the command following the +label is the next command applied to the +current line. If no label is specified, +control falls through to the end of the script, so no more commands +are applied to the current line.

c [address1[,address2]]c\

text

+ +

Replace (change) the lines selected by the address with +text. When a range of lines is specified, +all lines as a group are replaced by a single copy of +text. The newline following each line of +text must be escaped by a backslash, except +the last line. The contents of the pattern space are, in effect, +deleted and no subsequent editing commands can be applied to it (or to +text).

d [address1[,address2]]d

Delete line(s) from pattern space. Thus, the line is not passed to standard +output. A new line of input is read and editing resumes with first +command in script.

D [address1[,address2]]D

Delete first part (up to embedded newline) of multiline pattern space created +by N command and resume editing with first command in +script. If this command empties the pattern space, then a new line +of input is read, as if the d command had been executed.

g [address1[,address2]]g

Copy (get) contents of hold space (see h or +H command) into the pattern space, wiping out +previous contents.

G [address1[,address2]]G

Append newline followed by contents of hold space (see +h or H command) to contents of +the pattern space. If hold space is empty, a newline is still +appended to the pattern space.

h [address1[,address2]]h

Copy pattern space into hold space, a special temporary buffer. +Previous contents of hold space are wiped out.

H [address1[,address2]]H

Append newline and contents of pattern space to contents of the hold +space. Even if hold space is empty, this command still appends the +newline first.

i [address1]i\

text

+ +

Insert text before each line matched by +address. (See a for +details on text.)

l [address1[,address2]]l

List the contents of the pattern space, showing nonprinting characters +as ASCII codes. Long lines are wrapped.

n [address1[,address2]]n

Read next line of input into pattern space. Current line is sent to +standard output. New line becomes current line and increments line +counter. Control passes to command following n +instead of resuming at the top of the script.

N [address1[,address2]]N

Append next input line to contents of pattern space; the new line is +separated from the previous contents of the pattern space by a newline. +(This command is designed to allow pattern matches across two +lines. Using \n to match the embedded newline, you can match +patterns across multiple lines.)

p [address1[,address2]]p

Print the addressed line(s). Note that this can result in duplicate +output unless default output is suppressed by using "#n" or +the -n + +command-line option. Typically used before commands that change flow +control (d, n, +b) and might prevent the current line from being +output.

P [address1[,address2]]P

Print first part (up to embedded newline) of multiline pattern space +created by N command. Same as p +if N has not been applied to a line.

q [address]q

Quit when address is encountered. The +addressed line is first written to output (if default output is not +suppressed), along with any text appended to it by previous +a or r commands.

r [address]r file

Read contents of file and append after the +contents of the pattern space. Exactly one space must be put between +r and the filename.

s [address1[,address2]]s/pattern/replacement/[flags]

Substitute replacement for +pattern on each addressed line. If pattern +addresses are used, the pattern // represents the +last pattern address specified. The following flags can be specified:

+ +

n: Replace nth instance of + /pattern/ on each addressed line. + n is any number in the range 1 to 512, and + the default is 1.
g: Replace all instances of /pattern/ on each + addressed line, not just the first instance.
p: Print the line if a successful substitution is done. If several + successful substitutions are done, multiple copies of the line will be + printed.
w file: Write the line to file if a replacement + was done. A maximum of 10 different files can be opened.

+ +

t [address1[,address2]]t [label]

Test if successful substitutions have been made on addressed lines, +and if so, branch to line marked by :label. +(See b and :.) If label is not +specified, control falls through to bottom of script.

w [address1[,address2]]w file

Append contents of pattern space to file. +This action occurs when the command is encountered rather than when +the pattern space is output. Exactly one space must separate the +w and the filename. A maximum of 10 different +files can be opened in a script. This command will create the file if +it does not exist; if the file exists, its contents will be +overwritten each time the script is executed. Multiple write commands +that direct output to the same file append to the end of the file.

x [address1[,address2]]x

Exchange contents of the pattern space with the contents of the hold +space.

y [address1[,address2]]y/abc/xyz/

Transform each character by position in string +abc to its equivalent in string +xyz.

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