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Sed Cheatsheet
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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 | |
====================================================================== | |
------------------------------------------------------------------------- | |
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) | |
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This is very helpful, thanks for putting all this together! March 5, 2023