Sed
 | Don't forget the -i option to make your file edit "in place" |
Contents
Move Nested Files to Flat Date Structure
Just like in the Organize music files article, you might need to organize your Photo files. Let's say you use Shotwell to organize your files on import, but inadvertently switch the structure of imported files from YYYY-MM-DD to YYYY/MM/DD Big difference. How do you quickly move hundreds of files from the latter to the former structure?
The following command will use find to find all files; ignoring any hidden files or files in hidden directories. Then sed just turns the results into a command that uses back-references to put things in the right place. Note that the command as shown doesn't actually do anything but print out the commands that we use sed to construct -- so you can refine it if it's not correct. By adding an e at the end like %e' in the final invocation, it instructs sed to execute those as commands.
find /home/greg/Pictures/2017/ -type f | grep --perl-regex -v '/\.' | sed 's%/home/greg/Pictures/2017/\([0-9][0-9]\)/\([0-9][0-9]\).*%mkdir -p "/home/greg/Pictures/2017-\1-\2" \&\& mv "&" "/home/greg/Pictures/2017-\1-\2/"%'
When you're done with that, you'll have some detritus left over in your filesystem. find /home/greg/Pictures/2017/ will show you what's there, and adding the -delete option to find will delete those files.
Resources
- Tutorial: http://www.grymoire.com/Unix/Sed.html
- Another Cheatsheet: http://www.grymoire.com/Unix/SedChart.pdf
- Eric Pement's pages on sed: http://www.student.northpark.edu/pemente/sed/index.htm
One-liners
-------------------------------------------------------------------------
USEFUL ONE-LINE SCRIPTS FOR SED (Unix stream editor) Dec. 29, 2005
Compiled by Eric Pement - pemente[at]northpark[dot]edu version 5.5
Latest version of this file (in English) is usually at:
http://sed.sourceforge.net/sed1line.txt
http://www.pement.org/sed/sed1line.txt
This file will also available in other languages:
Chinese - http://sed.sourceforge.net/sed1line_zh-CN.html
Czech - http://sed.sourceforge.net/sed1line_cz.html
Dutch - http://sed.sourceforge.net/sed1line_nl.html
French - http://sed.sourceforge.net/sed1line_fr.html
German - http://sed.sourceforge.net/sed1line_de.html
Italian - (pending)
Portuguese - http://sed.sourceforge.net/sed1line_pt-BR.html
Spanish - (pending)
FILE SPACING:
# double space a file
sed G
# double space a file which already has blank lines in it. Output file
# should contain no more than one blank line between lines of text.
sed '/^$/d;G'
# triple space a file
sed 'G;G'
# undo double-spacing (assumes even-numbered lines are always blank)
sed 'n;d'
# insert a blank line above every line which matches "regex"
sed '/regex/{x;p;x;}'
# insert a blank line below every line which matches "regex"
sed '/regex/G'
# insert a blank line above and below every line which matches "regex"
sed '/regex/{x;p;x;G;}'
NUMBERING:
# number each line of a file (simple left alignment). Using a tab (see
# note on '\t' at end of file) instead of space will preserve margins.
sed = filename | sed 'N;s/\n/\t/'
# number each line of a file (number on left, right-aligned)
sed = filename | sed 'N; s/^/ /; s/ *\(.\{6,\}\)\n/\1 /'
# number each line of file, but only print numbers if line is not blank
sed '/./=' filename | sed '/./N; s/\n/ /'
# count lines (emulates "wc -l")
sed -n '$='
TEXT CONVERSION AND SUBSTITUTION:
# IN UNIX ENVIRONMENT: convert DOS newlines (CR/LF) to Unix format.
sed 's/.$//' # assumes that all lines end with CR/LF
sed 's/^M$//' # in bash/tcsh, press Ctrl-V then Ctrl-M
sed 's/\x0D$//' # works on ssed, gsed 3.02.80 or higher
# IN UNIX ENVIRONMENT: convert Unix newlines (LF) to DOS format.
sed "s/$/`echo -e \\\r`/" # command line under ksh
sed 's/$'"/`echo \\\r`/" # command line under bash
sed "s/$/`echo \\\r`/" # command line under zsh
sed 's/$/\r/' # gsed 3.02.80 or higher
# IN DOS ENVIRONMENT: convert Unix newlines (LF) to DOS format.
sed "s/$//" # method 1
sed -n p # method 2
# IN DOS ENVIRONMENT: convert DOS newlines (CR/LF) to Unix format.
# Can only be done with UnxUtils sed, version 4.0.7 or higher. The
# UnxUtils version can be identified by the custom "--text" switch
# which appears when you use the "--help" switch. Otherwise, changing
# DOS newlines to Unix newlines cannot be done with sed in a DOS
# environment. Use "tr" instead.
sed "s/\r//" infile >outfile # UnxUtils sed v4.0.7 or higher
tr -d \r <infile >outfile # GNU tr version 1.22 or higher
# delete leading whitespace (spaces, tabs) from front of each line
# aligns all text flush left
sed 's/^[ \t]*//' # see note on '\t' at end of file
# delete trailing whitespace (spaces, tabs) from end of each line
sed 's/[ \t]*$//' # see note on '\t' at end of file
# delete BOTH leading and trailing whitespace from each line
sed 's/^[ \t]*//;s/[ \t]*$//'
# insert 5 blank spaces at beginning of each line (make page offset)
sed 's/^/ /'
# align all text flush right on a 79-column width
sed -e :a -e 's/^.\{1,78\}$/ &/;ta' # set at 78 plus 1 space
# center all text in the middle of 79-column width. In method 1,
# spaces at the beginning of the line are significant, and trailing
# spaces are appended at the end of the line. In method 2, spaces at
# the beginning of the line are discarded in centering the line, and
# no trailing spaces appear at the end of lines.
sed -e :a -e 's/^.\{1,77\}$/ & /;ta' # method 1
sed -e :a -e 's/^.\{1,77\}$/ &/;ta' -e 's/\( *\)\1/\1/' # method 2
# substitute (find and replace) "foo" with "bar" on each line
sed 's/foo/bar/' # replaces only 1st instance in a line
sed 's/foo/bar/4' # replaces only 4th instance in a line
sed 's/foo/bar/g' # replaces ALL instances in a line
sed 's/\(.*\)foo\(.*foo\)/\1bar\2/' # replace the next-to-last case
sed 's/\(.*\)foo/\1bar/' # replace only the last case
# substitute "foo" with "bar" ONLY for lines which contain "baz"
sed '/baz/s/foo/bar/g'
# substitute "foo" with "bar" EXCEPT for lines which contain "baz"
sed '/baz/!s/foo/bar/g'
# change "scarlet" or "ruby" or "puce" to "red"
sed 's/scarlet/red/g;s/ruby/red/g;s/puce/red/g' # most seds
gsed 's/scarlet\|ruby\|puce/red/g' # GNU sed only
# reverse order of lines (emulates "tac")
# bug/feature in HHsed v1.5 causes blank lines to be deleted
sed '1!G;h;$!d' # method 1
sed -n '1!G;h;$p' # method 2
# reverse each character on the line (emulates "rev")
sed '/\n/!G;s/\(.\)\(.*\n\)/&\2\1/;//D;s/.//'
# join pairs of lines side-by-side (like "paste")
sed '$!N;s/\n/ /'
# if a line ends with a backslash, append the next line to it
sed -e :a -e '/\\$/N; s/\\\n//; ta'
# if a line begins with an equal sign, append it to the previous line
# and replace the "=" with a single space
sed -e :a -e '$!N;s/\n=/ /;ta' -e 'P;D'
# add commas to numeric strings, changing "1234567" to "1,234,567"
gsed ':a;s/\B[0-9]\{3\}\>/,&/;ta' # GNU sed
sed -e :a -e 's/\(.*[0-9]\)\([0-9]\{3\}\)/\1,\2/;ta' # other seds
# add commas to numbers with decimal points and minus signs (GNU sed)
gsed -r ':a;s/(^|[^0-9.])([0-9]+)([0-9]{3})/\1\2,\3/g;ta'
# add a blank line every 5 lines (after lines 5, 10, 15, 20, etc.)
gsed '0~5G' # GNU sed only
sed 'n;n;n;n;G;' # other seds
SELECTIVE PRINTING OF CERTAIN LINES:
# print first 10 lines of file (emulates behavior of "head")
sed 10q
# print first line of file (emulates "head -1")
sed q
# print the last 10 lines of a file (emulates "tail")
sed -e :a -e '$q;N;11,$D;ba'
# print the last 2 lines of a file (emulates "tail -2")
sed '$!N;$!D'
# print the last line of a file (emulates "tail -1")
sed '$!d' # method 1
sed -n '$p' # method 2
# print the next-to-the-last line of a file
sed -e '$!{h;d;}' -e x # for 1-line files, print blank line
sed -e '1{$q;}' -e '$!{h;d;}' -e x # for 1-line files, print the line
sed -e '1{$d;}' -e '$!{h;d;}' -e x # for 1-line files, print nothing
# print only lines which match regular expression (emulates "grep")
sed -n '/regexp/p' # method 1
sed '/regexp/!d' # method 2
# print only lines which do NOT match regexp (emulates "grep -v")
sed -n '/regexp/!p' # method 1, corresponds to above
sed '/regexp/d' # method 2, simpler syntax
# print the line immediately before a regexp, but not the line
# containing the regexp
sed -n '/regexp/{g;1!p;};h'
# print the line immediately after a regexp, but not the line
# containing the regexp
sed -n '/regexp/{n;p;}'
# print 1 line of context before and after regexp, with line number
# indicating where the regexp occurred (similar to "grep -A1 -B1")
sed -n -e '/regexp/{=;x;1!p;g;$!N;p;D;}' -e h
# grep for AAA and BBB and CCC (in any order)
sed '/AAA/!d; /BBB/!d; /CCC/!d'
# grep for AAA and BBB and CCC (in that order)
sed '/AAA.*BBB.*CCC/!d'
# grep for AAA or BBB or CCC (emulates "egrep")
sed -e '/AAA/b' -e '/BBB/b' -e '/CCC/b' -e d # most seds
gsed '/AAA\|BBB\|CCC/!d' # GNU sed only
# print paragraph if it contains AAA (blank lines separate paragraphs)
# HHsed v1.5 must insert a 'G;' after 'x;' in the next 3 scripts below
sed -e '/./{H;$!d;}' -e 'x;/AAA/!d;'
# print paragraph if it contains AAA and BBB and CCC (in any order)
sed -e '/./{H;$!d;}' -e 'x;/AAA/!d;/BBB/!d;/CCC/!d'
# print paragraph if it contains AAA or BBB or CCC
sed -e '/./{H;$!d;}' -e 'x;/AAA/b' -e '/BBB/b' -e '/CCC/b' -e d
gsed '/./{H;$!d;};x;/AAA\|BBB\|CCC/b;d' # GNU sed only
# print only lines of 65 characters or longer
sed -n '/^.\{65\}/p'
# print only lines of less than 65 characters
sed -n '/^.\{65\}/!p' # method 1, corresponds to above
sed '/^.\{65\}/d' # method 2, simpler syntax
# print section of file from regular expression to end of file
sed -n '/regexp/,$p'
# print section of file based on line numbers (lines 8-12, inclusive)
sed -n '8,12p' # method 1
sed '8,12!d' # method 2
# print line number 52
sed -n '52p' # method 1
sed '52!d' # method 2
sed '52q;d' # method 3, efficient on large files
# beginning at line 3, print every 7th line
gsed -n '3~7p' # GNU sed only
sed -n '3,${p;n;n;n;n;n;n;}' # other seds
# print section of file between two regular expressions (inclusive)
sed -n '/Iowa/,/Montana/p' # case sensitive
SELECTIVE DELETION OF CERTAIN LINES:
# print all of file EXCEPT section between 2 regular expressions
sed '/Iowa/,/Montana/d'
# delete duplicate, consecutive lines from a file (emulates "uniq").
# First line in a set of duplicate lines is kept, rest are deleted.
sed '$!N; /^\(.*\)\n\1$/!P; D'
# delete duplicate, nonconsecutive lines from a file. Beware not to
# overflow the buffer size of the hold space, or else use GNU sed.
sed -n 'G; s/\n/&&/; /^\([ -~]*\n\).*\n\1/d; s/\n//; h; P'
# delete all lines except duplicate lines (emulates "uniq -d").
sed '$!N; s/^\(.*\)\n\1$/\1/; t; D'
# delete the first 10 lines of a file
sed '1,10d'
# delete the last line of a file
sed '$d'
# delete the last 2 lines of a file
sed 'N;$!P;$!D;$d'
# delete the last 10 lines of a file
sed -e :a -e '$d;N;2,10ba' -e 'P;D' # method 1
sed -n -e :a -e '1,10!{P;N;D;};N;ba' # method 2
# delete every 8th line
gsed '0~8d' # GNU sed only
sed 'n;n;n;n;n;n;n;d;' # other seds
# delete lines matching pattern
sed '/pattern/d'
# delete ALL blank lines from a file (same as "grep '.' ")
sed '/^$/d' # method 1
sed '/./!d' # method 2
# delete all CONSECUTIVE blank lines from file except the first; also
# deletes all blank lines from top and end of file (emulates "cat -s")
sed '/./,/^$/!d' # method 1, allows 0 blanks at top, 1 at EOF
sed '/^$/N;/\n$/D' # method 2, allows 1 blank at top, 0 at EOF
# delete all CONSECUTIVE blank lines from file except the first 2:
sed '/^$/N;/\n$/N;//D'
# delete all leading blank lines at top of file
sed '/./,$!d'
# delete all trailing blank lines at end of file
sed -e :a -e '/^\n*$/{$d;N;ba' -e '}' # works on all seds
sed -e :a -e '/^\n*$/N;/\n$/ba' # ditto, except for gsed 3.02.*
# delete the last line of each paragraph
sed -n '/^$/{p;h;};/./{x;/./p;}'
SPECIAL APPLICATIONS:
# remove nroff overstrikes (char, backspace) from man pages. The 'echo'
# command may need an -e switch if you use Unix System V or bash shell.
sed "s/.`echo \\\b`//g" # double quotes required for Unix environment
sed 's/.^H//g' # in bash/tcsh, press Ctrl-V and then Ctrl-H
sed 's/.\x08//g' # hex expression for sed 1.5, GNU sed, ssed
# get Usenet/e-mail message header
sed '/^$/q' # deletes everything after first blank line
# get Usenet/e-mail message body
sed '1,/^$/d' # deletes everything up to first blank line
# get Subject header, but remove initial "Subject: " portion
sed '/^Subject: */!d; s///;q'
# get return address header
sed '/^Reply-To:/q; /^From:/h; /./d;g;q'
# parse out the address proper. Pulls out the e-mail address by itself
# from the 1-line return address header (see preceding script)
sed 's/ *(.*)//; s/>.*//; s/.*[:<] *//'
# add a leading angle bracket and space to each line (quote a message)
sed 's/^/> /'
# delete leading angle bracket & space from each line (unquote a message)
sed 's/^> //'
# remove most HTML tags (accommodates multiple-line tags)
sed -e :a -e 's/<[^>]*>//g;/</N;//ba'
# extract multi-part uuencoded binaries, removing extraneous header
# info, so that only the uuencoded portion remains. Files passed to
# sed must be passed in the proper order. Version 1 can be entered
# from the command line; version 2 can be made into an executable
# Unix shell script. (Modified from a script by Rahul Dhesi.)
sed '/^end/,/^begin/d' file1 file2 ... fileX | uudecode # vers. 1
sed '/^end/,/^begin/d' "$@" | uudecode # vers. 2
# sort paragraphs of file alphabetically. Paragraphs are separated by blank
# lines. GNU sed uses \v for vertical tab, or any unique char will do.
sed '/./{H;d;};x;s/\n/={NL}=/g' file | sort | sed '1s/={NL}=//;s/={NL}=/\n/g'
gsed '/./{H;d};x;y/\n/\v/' file | sort | sed '1s/\v//;y/\v/\n/'
# zip up each .TXT file individually, deleting the source file and
# setting the name of each .ZIP file to the basename of the .TXT file
# (under DOS: the "dir /b" switch returns bare filenames in all caps).
echo @echo off >zipup.bat
dir /b *.txt | sed "s/^\(.*\)\.TXT/pkzip -mo \1 \1.TXT/" >>zipup.bat
TYPICAL USE: Sed takes one or more editing commands and applies all of
them, in sequence, to each line of input. After all the commands have
been applied to the first input line, that line is output and a second
input line is taken for processing, and the cycle repeats. The
preceding examples assume that input comes from the standard input
device (i.e, the console, normally this will be piped input). One or
more filenames can be appended to the command line if the input does
not come from stdin. Output is sent to stdout (the screen). Thus:
cat filename | sed '10q' # uses piped input
sed '10q' filename # same effect, avoids a useless "cat"
sed '10q' filename > newfile # redirects output to disk
For additional syntax instructions, including the way to apply editing
commands from a disk file instead of the command line, consult "sed &
awk, 2nd Edition," by Dale Dougherty and Arnold Robbins (O'Reilly,
1997; http://www.ora.com), "UNIX Text Processing," by Dale Dougherty
and Tim O'Reilly (Hayden Books, 1987) or the tutorials by Mike Arst
distributed in U-SEDIT2.ZIP (many sites). To fully exploit the power
of sed, one must understand "regular expressions." For this, see
"Mastering Regular Expressions" by Jeffrey Friedl (O'Reilly, 1997).
The manual ("man") pages on Unix systems may be helpful (try "man
sed", "man regexp", or the subsection on regular expressions in "man
ed"), but man pages are notoriously difficult. They are not written to
teach sed use or regexps to first-time users, but as a reference text
for those already acquainted with these tools.
QUOTING SYNTAX: The preceding examples use single quotes ('...')
instead of double quotes ("...") to enclose editing commands, since
sed is typically used on a Unix platform. Single quotes prevent the
Unix shell from intrepreting the dollar sign ($) and backquotes
(`...`), which are expanded by the shell if they are enclosed in
double quotes. Users of the "csh" shell and derivatives will also need
to quote the exclamation mark (!) with the backslash (i.e., \!) to
properly run the examples listed above, even within single quotes.
Versions of sed written for DOS invariably require double quotes
("...") instead of single quotes to enclose editing commands.
USE OF '\t' IN SED SCRIPTS: For clarity in documentation, we have used
the expression '\t' to indicate a tab character (0x09) in the scripts.
However, most versions of sed do not recognize the '\t' abbreviation,
so when typing these scripts from the command line, you should press
the TAB key instead. '\t' is supported as a regular expression
metacharacter in awk, perl, and HHsed, sedmod, and GNU sed v3.02.80.
VERSIONS OF SED: Versions of sed do differ, and some slight syntax
variation is to be expected. In particular, most do not support the
use of labels (:name) or branch instructions (b,t) within editing
commands, except at the end of those commands. We have used the syntax
which will be portable to most users of sed, even though the popular
GNU versions of sed allow a more succinct syntax. When the reader sees
a fairly long command such as this:
sed -e '/AAA/b' -e '/BBB/b' -e '/CCC/b' -e d
it is heartening to know that GNU sed will let you reduce it to:
sed '/AAA/b;/BBB/b;/CCC/b;d' # or even
sed '/AAA\|BBB\|CCC/b;d'
In addition, remember that while many versions of sed accept a command
like "/one/ s/RE1/RE2/", some do NOT allow "/one/! s/RE1/RE2/", which
contains space before the 's'. Omit the space when typing the command.
OPTIMIZING FOR SPEED: If execution speed needs to be increased (due to
large input files or slow processors or hard disks), substitution will
be executed more quickly if the "find" expression is specified before
giving the "s/.../.../" instruction. Thus:
sed 's/foo/bar/g' filename # standard replace command
sed '/foo/ s/foo/bar/g' filename # executes more quickly
sed '/foo/ s//bar/g' filename # shorthand sed syntax
On line selection or deletion in which you only need to output lines
from the first part of the file, a "quit" command (q) in the script
will drastically reduce processing time for large files. Thus:
sed -n '45,50p' filename # print line nos. 45-50 of a file
sed -n '51q;45,50p' filename # same, but executes much faster
If you have any additional scripts to contribute or if you find errors
in this document, please send e-mail to the compiler. Indicate the
version of sed you used, the operating system it was compiled for, and
the nature of the problem. To qualify as a one-liner, the command line
must be 65 characters or less. Various scripts in this file have been
written or contributed by:
Al Aab # founder of "seders" list
Edgar Allen # various
Yiorgos Adamopoulos # various
Dale Dougherty # author of "sed & awk"
Carlos Duarte # author of "do it with sed"
Eric Pement # author of this document
Ken Pizzini # author of GNU sed v3.02
S.G. Ravenhall # great de-html script
Greg Ubben # many contributions & much help
-------------------------------------------------------------------------
Explained
- http://www.catonmat.net/blog/sed-one-liners-explained-part-one/
- http://www.catonmat.net/blog/sed-one-liners-explained-part-two/
- http://www.catonmat.net/blog/sed-one-liners-explained-part-three/
Cheatsheet
http://www.catonmat.net/download/sed.stream.editor.cheat.sheet.pdf
.---------------------------------------------------------------------.
| |
| UNIX Stream Editor |
| Sed Cheat Sheet |
| |
'---------------------------------------------------------------------'
| Peteris Krumins (peter@catonmat.net), 2007.08.22 |
| http://www.catonmat.net - good coders code, great reuse |
'---------------------------------------------------------------------'
==================== How Commands Affect Streams ====================
.---------.-----------.-----------------------------------------.
| | | Modifications to: |
| | Address '---------.---------.---------.-----------'
| Command | or Range | Input | Output | Pattern | Hold |
| | | Stream | Stream | Space | Buffer |
'---------+-----------+---------+---------+---------+-----------'
| = | - | - | + | - | - |
| a | 1 | - | + | - | - |
| b | 2 | - | - | - | - |
| c | 2 | - | + | - | - |
| d | 2 | + | - | + | - |
| D | 2 | + | - | + | - |
| g | 2 | - | - | + | - |
| G | 2 | - | - | + | - |
| h | 2 | - | - | - | + |
| H | 2 | - | - | - | + |
| i | 1 | - | + | - | - |
| l | 1 | - | + | - | - |
| n | 2 | + | * | - | - |
| N | 2 | + | - | + | - |
| p | 2 | - | + | - | - |
| P | 2 | - | + | - | - |
| q | 1 | - | - | - | - |
| r | 1 | - | + | - | - |
| s | 2 | - | - | + | - |
| t | 2 | - | - | - | - |
| w | 2 | - | + | - | - |
| x | 2 | - | - | + | + |
| y | 2 | - | - | + | - |
'---------'-----------'---------'---------'---------'-----------'
Modifications to:
1 Command takes single address or pattern.
2 Command takes pair of addresses.
- Command does not modify the buffer.
+ Command modifies the buffer.
* The ``n'' command may or may not generate output depending
on the ``-n'' command option.
========================== Command Summary ==========================
.----------------.----------------------------------------------------.
| | |
| Command | Description |
| | |
'----------------+----------------------------------------------------'
| # | Adds a comment. |
'----------------+----------------------------------------------------'
| = | The "=" command prints the current line number to |
| | standard output. |
'----------------+----------------------------------------------------'
| a \ | The "a" command appends text after the |
| text | range or pattern. |
'----------------+----------------------------------------------------'
| b label | The "b" command branches to the label. You can |
| | specify a label with a text string followed by a |
| | colon. If no label is there, branch to the end of |
| | the script. |
'----------------+----------------------------------------------------'
| c \ | The "c" command changes the current line with |
| text | text. |
'----------------+----------------------------------------------------'
| d | The "d" command deletes the current pattern space, |
| | reads in the next line, puts the new line into the |
| | pattern space, and aborts the current command, and |
| | starts execution at the first sed command. |
'----------------+----------------------------------------------------'
| D | The "D" command deletes the first portion of the |
| | pattern space, up to the new line character, |
| | leaving the rest of the pattern alone. |
'----------------+----------------------------------------------------'
| g | Instead of exchanging (the "x" command) the hold |
| | space with the pattern space, you can copy the |
| | hold space to the pattern space with the "g" |
| | command. |
'----------------+----------------------------------------------------'
| G | If you want to append to the pattern space, use |
| | the "G" command. |
'----------------+----------------------------------------------------'
| h | The "h" command copies the pattern buffer into the |
| | hold buffer. |
'----------------+----------------------------------------------------'
| H | The "H" command allows you to combine several |
| | lines in the hold buffer. It acts like the "N" |
| | command as lines are appended to the buffer, with |
| | a "\n" between the lines. You can save several |
| | lines in the hold buffer, and print them only if a |
| | particular pattern is found later. |
'----------------+----------------------------------------------------'
| i \ | You can insert text before the pattern with |
| text | the "i" command. |
'----------------+----------------------------------------------------'
| l | The "l" command prints the current pattern space. |
| | It is therefore useful in debugging sed scripts. |
| | It also converts unprintable characters into |
| | printing characters by outputting the value in |
| | octal preceded by a "\" character. |
'----------------+----------------------------------------------------'
| n | The "n" command will print out the current pattern |
| | space (unless the "-n" flag is used), empty the |
| | current pattern space, and read in the next |
| | line of input. |
'----------------+----------------------------------------------------'
| N | The "N" command does not print out the current |
| | pattern space and does not empty the pattern |
| | space. It reads in the next line, but appends a |
| | new line character along with the input line |
| | itself to the pattern space. |
'----------------+----------------------------------------------------'
| p | Another useful command is the print command: "p". |
| | If sed wasn't started with an "-n" option, the "p" |
| | command will duplicate the input. The "p" command |
| | prints the entire pattern space. |
'----------------+----------------------------------------------------'
| P | The "P" command only prints the first part of the |
| | pattern space, up to the NEWLINE character. |
'----------------+----------------------------------------------------'
| q | There is one more simple command that can restrict |
| | the changes to a set of lines. It is the "q" |
| | command: quit. This command is most useful when |
| | you wish to abort the editing after some condition |
| | is reached. |
'----------------+----------------------------------------------------'
| r filename | The "r" command will append text from filename |
| | after the range or pattern. |
'----------------+----------------------------------------------------'
| s/regex/repl/ | The substitute command replaces all occurrences of |
| | the regular expression (regex) with repl(acement) |
'----------------+----------------------------------------------------'
| t label | You can execute a branch if a pattern is found. |
| | You may want to execute a branch only if a |
| | substitution is made. The command "t label" will |
| | branch to the label if the last substitute command |
| | modified the pattern space. |
'----------------+----------------------------------------------------'
| w filename | With this command, you can specify a filename that |
| | will receive the modified data. |
'----------------+----------------------------------------------------'
| x | The "x" command exchanges the hold buffer and the |
| | pattern buffer. |
'----------------+----------------------------------------------------'
| y/source/dest/ | Transliterate the characters in the pattern space, |
| | which appear in source to the corresponding |
| | character in dest(ination). |
'----------------'----------------------------------------------------'
======================== Command Extensions =========================
.----------------.----------------------------------------------------.
| | |
| Command | Description |
| | |
'----------------+----------------------------------------------------'
| Q | Immediately quit the sed script without processing |
| | any more input. (zero or one address command) |
'----------------+----------------------------------------------------'
| R filename | Append a line read from filename. (zero or one |
| | address command). |
'----------------+----------------------------------------------------'
| T label | If no s/// has done a successful substitution |
| | since the last input line was read and since the |
| | last t or T command, then branch to label; |
| | if label is omitted, branch to end of script. |
| | (accepts address range). |
'----------------+----------------------------------------------------'
| W filename | Write the first line of the current pattern space |
| | to filename. (accepts address range). |
'----------------'----------------------------------------------------'
======================= Address Range Summary =======================
.----------------.----------------------------------------------------.
| | |
| Format | Description |
| | |
'----------------+----------------------------------------------------'
| number | Match only the specified line number. |
'----------------+----------------------------------------------------'
| first~step | Match every step'th line starting with line first. |
'----------------+----------------------------------------------------'
| $ | Match the last line. |
'----------------+----------------------------------------------------'
| 0, addr2 | Start out in "matched first address" state, |
| | until addr2 is found. |
'----------------+----------------------------------------------------'
| /regex/ | Match lines matching the regular expression regex. |
'----------------+----------------------------------------------------'
| addr1,+N | Will match addr1 and the N lines following addr1. |
'----------------+----------------------------------------------------'
| \cregexc | Match lines matching the regular expression regex. |
| | The c may be any character. |
'----------------+----------------------------------------------------'
| addr1,~N | Will match addr1 and the lines following addr1 |
| | until the next line whose input line number |
| | is a multiple of N. |
'----------------'----------------------------------------------------'
============== GNU Sed's Command Line Argument Summary ==============
.---------------------.-----------------------------------------------.
| | |
| Argument | Description |
| | |
'---------------------+-----------------------------------------------'
| -n | |
| --quiet | Suppress automatic printing of pattern space. |
| --silent | |
'---------------------+-----------------------------------------------'
| -e script | |
| --expression=script | Add the script to the commands to be executed.|
| | |
'---------------------+-----------------------------------------------'
| -f script-file | Add the contents of script-file to the |
| --file=script-file | commands to be executed. |
'---------------------+-----------------------------------------------'
| -i[suffix] | Sdit files in place (makes backup if |
| --in-place[=suffix] | extension supplied). |
'---------------------+-----------------------------------------------'
| -l N | Specify the desired line-wrap length for |
| --line-length=N | the `l' command. |
'---------------------+-----------------------------------------------'
| -r | Use extended regular expressions in the |
| --regexp-extended | script. |
'---------------------+-----------------------------------------------'
| -s | Consider files as separate rather than as a |
| --separate | single continuous long stream. |
'---------------------+-----------------------------------------------'
| -u | Load minimal amounts of data from the input |
| --unbuffered | files and flush the output buffers more often.|
'---------------------+-----------------------------------------------'
| --help | Display this help and exit |
'---------------------+-----------------------------------------------'
| -V | Output version information and exit |
| --version | |
'---------------------'-----------------------------------------------'
=====================================================================
.---------------------------------------------------------------------.
| Peteris Krumins (peter@catonmat.net), 2007.08.22 |
| http://www.catonmat.net - good coders code, great reuse |
'---------------------------------------------------------------------'