add sed mini-doc
This commit is contained in:
Denis Vlasenko
parent
40276648ab
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425
editors/sed1line.txt
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425
editors/sed1line.txt
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http://www.student.northpark.edu/pemente/sed/sed1line.txt
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-------------------------------------------------------------------------
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HANDY ONE-LINERS FOR SED (Unix stream editor) Apr. 26, 2004
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compiled by Eric Pement - pemente[at]northpark[dot]edu version 5.4
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Latest version of this file is usually at:
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http://sed.sourceforge.net/sed1line.txt
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http://www.student.northpark.edu/pemente/sed/sed1line.txt
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This file is also available in Portuguese at:
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http://www.lrv.ufsc.br/wmaker/sed_ptBR.html
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FILE SPACING:
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# double space a file
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sed G
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# double space a file which already has blank lines in it. Output file
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# should contain no more than one blank line between lines of text.
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sed '/^$/d;G'
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# triple space a file
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sed 'G;G'
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# undo double-spacing (assumes even-numbered lines are always blank)
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sed 'n;d'
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# insert a blank line above every line which matches "regex"
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sed '/regex/{x;p;x;}'
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# insert a blank line below every line which matches "regex"
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sed '/regex/G'
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# insert a blank line above and below every line which matches "regex"
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sed '/regex/{x;p;x;G;}'
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NUMBERING:
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# number each line of a file (simple left alignment). Using a tab (see
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# note on '\t' at end of file) instead of space will preserve margins.
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sed = filename | sed 'N;s/\n/\t/'
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# number each line of a file (number on left, right-aligned)
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sed = filename | sed 'N; s/^/ /; s/ *\(.\{6,\}\)\n/\1 /'
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# number each line of file, but only print numbers if line is not blank
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sed '/./=' filename | sed '/./N; s/\n/ /'
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# count lines (emulates "wc -l")
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sed -n '$='
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TEXT CONVERSION AND SUBSTITUTION:
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# IN UNIX ENVIRONMENT: convert DOS newlines (CR/LF) to Unix format
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sed 's/.$//' # assumes that all lines end with CR/LF
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sed 's/^M$//' # in bash/tcsh, press Ctrl-V then Ctrl-M
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sed 's/\x0D$//' # gsed 3.02.80, but top script is easier
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# IN UNIX ENVIRONMENT: convert Unix newlines (LF) to DOS format
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sed "s/$/`echo -e \\\r`/" # command line under ksh
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sed 's/$'"/`echo \\\r`/" # command line under bash
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sed "s/$/`echo \\\r`/" # command line under zsh
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sed 's/$/\r/' # gsed 3.02.80
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# IN DOS ENVIRONMENT: convert Unix newlines (LF) to DOS format
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sed "s/$//" # method 1
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sed -n p # method 2
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# IN DOS ENVIRONMENT: convert DOS newlines (CR/LF) to Unix format
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# Can only be done with UnxUtils sed, version 4.0.7 or higher.
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# Cannot be done with other DOS versions of sed. Use "tr" instead.
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sed "s/\r//" infile >outfile # UnxUtils sed v4.0.7 or higher
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tr -d \r <infile >outfile # GNU tr version 1.22 or higher
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# delete leading whitespace (spaces, tabs) from front of each line
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# aligns all text flush left
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sed 's/^[ \t]*//' # see note on '\t' at end of file
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# delete trailing whitespace (spaces, tabs) from end of each line
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sed 's/[ \t]*$//' # see note on '\t' at end of file
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# delete BOTH leading and trailing whitespace from each line
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sed 's/^[ \t]*//;s/[ \t]*$//'
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# insert 5 blank spaces at beginning of each line (make page offset)
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sed 's/^/ /'
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# align all text flush right on a 79-column width
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sed -e :a -e 's/^.\{1,78\}$/ &/;ta' # set at 78 plus 1 space
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# center all text in the middle of 79-column width. In method 1,
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# spaces at the beginning of the line are significant, and trailing
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# spaces are appended at the end of the line. In method 2, spaces at
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# the beginning of the line are discarded in centering the line, and
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# no trailing spaces appear at the end of lines.
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sed -e :a -e 's/^.\{1,77\}$/ & /;ta' # method 1
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sed -e :a -e 's/^.\{1,77\}$/ &/;ta' -e 's/\( *\)\1/\1/' # method 2
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# substitute (find and replace) "foo" with "bar" on each line
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sed 's/foo/bar/' # replaces only 1st instance in a line
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sed 's/foo/bar/4' # replaces only 4th instance in a line
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sed 's/foo/bar/g' # replaces ALL instances in a line
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sed 's/\(.*\)foo\(.*foo\)/\1bar\2/' # replace the next-to-last case
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sed 's/\(.*\)foo/\1bar/' # replace only the last case
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# substitute "foo" with "bar" ONLY for lines which contain "baz"
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sed '/baz/s/foo/bar/g'
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# substitute "foo" with "bar" EXCEPT for lines which contain "baz"
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sed '/baz/!s/foo/bar/g'
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# change "scarlet" or "ruby" or "puce" to "red"
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sed 's/scarlet/red/g;s/ruby/red/g;s/puce/red/g' # most seds
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gsed 's/scarlet\|ruby\|puce/red/g' # GNU sed only
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# reverse order of lines (emulates "tac")
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# bug/feature in HHsed v1.5 causes blank lines to be deleted
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sed '1!G;h;$!d' # method 1
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sed -n '1!G;h;$p' # method 2
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# reverse each character on the line (emulates "rev")
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sed '/\n/!G;s/\(.\)\(.*\n\)/&\2\1/;//D;s/.//'
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# join pairs of lines side-by-side (like "paste")
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sed '$!N;s/\n/ /'
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# if a line ends with a backslash, append the next line to it
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sed -e :a -e '/\\$/N; s/\\\n//; ta'
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# if a line begins with an equal sign, append it to the previous line
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# and replace the "=" with a single space
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sed -e :a -e '$!N;s/\n=/ /;ta' -e 'P;D'
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# add commas to numeric strings, changing "1234567" to "1,234,567"
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gsed ':a;s/\B[0-9]\{3\}\>/,&/;ta' # GNU sed
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sed -e :a -e 's/\(.*[0-9]\)\([0-9]\{3\}\)/\1,\2/;ta' # other seds
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# add commas to numbers with decimal points and minus signs (GNU sed)
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gsed ':a;s/\(^\|[^0-9.]\)\([0-9]\+\)\([0-9]\{3\}\)/\1\2,\3/g;ta'
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# add a blank line every 5 lines (after lines 5, 10, 15, 20, etc.)
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gsed '0~5G' # GNU sed only
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sed 'n;n;n;n;G;' # other seds
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SELECTIVE PRINTING OF CERTAIN LINES:
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# print first 10 lines of file (emulates behavior of "head")
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sed 10q
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# print first line of file (emulates "head -1")
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sed q
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# print the last 10 lines of a file (emulates "tail")
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sed -e :a -e '$q;N;11,$D;ba'
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# print the last 2 lines of a file (emulates "tail -2")
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sed '$!N;$!D'
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# print the last line of a file (emulates "tail -1")
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sed '$!d' # method 1
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sed -n '$p' # method 2
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# print only lines which match regular expression (emulates "grep")
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sed -n '/regexp/p' # method 1
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sed '/regexp/!d' # method 2
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# print only lines which do NOT match regexp (emulates "grep -v")
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sed -n '/regexp/!p' # method 1, corresponds to above
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sed '/regexp/d' # method 2, simpler syntax
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# print the line immediately before a regexp, but not the line
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# containing the regexp
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sed -n '/regexp/{g;1!p;};h'
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# print the line immediately after a regexp, but not the line
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# containing the regexp
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sed -n '/regexp/{n;p;}'
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# print 1 line of context before and after regexp, with line number
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# indicating where the regexp occurred (similar to "grep -A1 -B1")
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sed -n -e '/regexp/{=;x;1!p;g;$!N;p;D;}' -e h
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# grep for AAA and BBB and CCC (in any order)
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sed '/AAA/!d; /BBB/!d; /CCC/!d'
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# grep for AAA and BBB and CCC (in that order)
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sed '/AAA.*BBB.*CCC/!d'
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# grep for AAA or BBB or CCC (emulates "egrep")
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sed -e '/AAA/b' -e '/BBB/b' -e '/CCC/b' -e d # most seds
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gsed '/AAA\|BBB\|CCC/!d' # GNU sed only
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# print paragraph if it contains AAA (blank lines separate paragraphs)
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# HHsed v1.5 must insert a 'G;' after 'x;' in the next 3 scripts below
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sed -e '/./{H;$!d;}' -e 'x;/AAA/!d;'
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# print paragraph if it contains AAA and BBB and CCC (in any order)
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sed -e '/./{H;$!d;}' -e 'x;/AAA/!d;/BBB/!d;/CCC/!d'
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# print paragraph if it contains AAA or BBB or CCC
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sed -e '/./{H;$!d;}' -e 'x;/AAA/b' -e '/BBB/b' -e '/CCC/b' -e d
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gsed '/./{H;$!d;};x;/AAA\|BBB\|CCC/b;d' # GNU sed only
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# print only lines of 65 characters or longer
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sed -n '/^.\{65\}/p'
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# print only lines of less than 65 characters
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sed -n '/^.\{65\}/!p' # method 1, corresponds to above
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sed '/^.\{65\}/d' # method 2, simpler syntax
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# print section of file from regular expression to end of file
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sed -n '/regexp/,$p'
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# print section of file based on line numbers (lines 8-12, inclusive)
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sed -n '8,12p' # method 1
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sed '8,12!d' # method 2
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# print line number 52
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sed -n '52p' # method 1
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sed '52!d' # method 2
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sed '52q;d' # method 3, efficient on large files
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# beginning at line 3, print every 7th line
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gsed -n '3~7p' # GNU sed only
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sed -n '3,${p;n;n;n;n;n;n;}' # other seds
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# print section of file between two regular expressions (inclusive)
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sed -n '/Iowa/,/Montana/p' # case sensitive
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SELECTIVE DELETION OF CERTAIN LINES:
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# print all of file EXCEPT section between 2 regular expressions
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sed '/Iowa/,/Montana/d'
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# delete duplicate, consecutive lines from a file (emulates "uniq").
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# First line in a set of duplicate lines is kept, rest are deleted.
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sed '$!N; /^\(.*\)\n\1$/!P; D'
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# delete duplicate, nonconsecutive lines from a file. Beware not to
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# overflow the buffer size of the hold space, or else use GNU sed.
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sed -n 'G; s/\n/&&/; /^\([ -~]*\n\).*\n\1/d; s/\n//; h; P'
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# delete all lines except duplicate lines (emulates "uniq -d").
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sed '$!N; s/^\(.*\)\n\1$/\1/; t; D'
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# delete the first 10 lines of a file
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sed '1,10d'
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# delete the last line of a file
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sed '$d'
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# delete the last 2 lines of a file
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sed 'N;$!P;$!D;$d'
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# delete the last 10 lines of a file
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sed -e :a -e '$d;N;2,10ba' -e 'P;D' # method 1
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sed -n -e :a -e '1,10!{P;N;D;};N;ba' # method 2
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# delete every 8th line
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gsed '0~8d' # GNU sed only
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sed 'n;n;n;n;n;n;n;d;' # other seds
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# delete ALL blank lines from a file (same as "grep '.' ")
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sed '/^$/d' # method 1
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sed '/./!d' # method 2
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# delete all CONSECUTIVE blank lines from file except the first; also
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# deletes all blank lines from top and end of file (emulates "cat -s")
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sed '/./,/^$/!d' # method 1, allows 0 blanks at top, 1 at EOF
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sed '/^$/N;/\n$/D' # method 2, allows 1 blank at top, 0 at EOF
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# delete all CONSECUTIVE blank lines from file except the first 2:
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sed '/^$/N;/\n$/N;//D'
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# delete all leading blank lines at top of file
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sed '/./,$!d'
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# delete all trailing blank lines at end of file
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sed -e :a -e '/^\n*$/{$d;N;ba' -e '}' # works on all seds
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sed -e :a -e '/^\n*$/N;/\n$/ba' # ditto, except for gsed 3.02*
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# delete the last line of each paragraph
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sed -n '/^$/{p;h;};/./{x;/./p;}'
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SPECIAL APPLICATIONS:
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# remove nroff overstrikes (char, backspace) from man pages. The 'echo'
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# command may need an -e switch if you use Unix System V or bash shell.
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sed "s/.`echo \\\b`//g" # double quotes required for Unix environment
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sed 's/.^H//g' # in bash/tcsh, press Ctrl-V and then Ctrl-H
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sed 's/.\x08//g' # hex expression for sed v1.5
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# get Usenet/e-mail message header
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sed '/^$/q' # deletes everything after first blank line
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# get Usenet/e-mail message body
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sed '1,/^$/d' # deletes everything up to first blank line
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# get Subject header, but remove initial "Subject: " portion
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sed '/^Subject: */!d; s///;q'
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# get return address header
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sed '/^Reply-To:/q; /^From:/h; /./d;g;q'
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# parse out the address proper. Pulls out the e-mail address by itself
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# from the 1-line return address header (see preceding script)
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sed 's/ *(.*)//; s/>.*//; s/.*[:<] *//'
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# add a leading angle bracket and space to each line (quote a message)
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sed 's/^/> /'
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# delete leading angle bracket & space from each line (unquote a message)
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sed 's/^> //'
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# remove most HTML tags (accommodates multiple-line tags)
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sed -e :a -e 's/<[^>]*>//g;/</N;//ba'
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# extract multi-part uuencoded binaries, removing extraneous header
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# info, so that only the uuencoded portion remains. Files passed to
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# sed must be passed in the proper order. Version 1 can be entered
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# from the command line; version 2 can be made into an executable
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# Unix shell script. (Modified from a script by Rahul Dhesi.)
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sed '/^end/,/^begin/d' file1 file2 ... fileX | uudecode # vers. 1
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sed '/^end/,/^begin/d' "$@" | uudecode # vers. 2
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# zip up each .TXT file individually, deleting the source file and
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# setting the name of each .ZIP file to the basename of the .TXT file
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# (under DOS: the "dir /b" switch returns bare filenames in all caps).
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echo @echo off >zipup.bat
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dir /b *.txt | sed "s/^\(.*\)\.TXT/pkzip -mo \1 \1.TXT/" >>zipup.bat
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TYPICAL USE: Sed takes one or more editing commands and applies all of
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them, in sequence, to each line of input. After all the commands have
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been applied to the first input line, that line is output and a second
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input line is taken for processing, and the cycle repeats. The
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preceding examples assume that input comes from the standard input
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device (i.e, the console, normally this will be piped input). One or
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more filenames can be appended to the command line if the input does
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not come from stdin. Output is sent to stdout (the screen). Thus:
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cat filename | sed '10q' # uses piped input
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sed '10q' filename # same effect, avoids a useless "cat"
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sed '10q' filename > newfile # redirects output to disk
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For additional syntax instructions, including the way to apply editing
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commands from a disk file instead of the command line, consult "sed &
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awk, 2nd Edition," by Dale Dougherty and Arnold Robbins (O'Reilly,
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1997; http://www.ora.com), "UNIX Text Processing," by Dale Dougherty
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and Tim O'Reilly (Hayden Books, 1987) or the tutorials by Mike Arst
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distributed in U-SEDIT2.ZIP (many sites). To fully exploit the power
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of sed, one must understand "regular expressions." For this, see
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"Mastering Regular Expressions" by Jeffrey Friedl (O'Reilly, 1997).
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The manual ("man") pages on Unix systems may be helpful (try "man
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sed", "man regexp", or the subsection on regular expressions in "man
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ed"), but man pages are notoriously difficult. They are not written to
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teach sed use or regexps to first-time users, but as a reference text
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for those already acquainted with these tools.
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QUOTING SYNTAX: The preceding examples use single quotes ('...')
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instead of double quotes ("...") to enclose editing commands, since
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sed is typically used on a Unix platform. Single quotes prevent the
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Unix shell from intrepreting the dollar sign ($) and backquotes
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(`...`), which are expanded by the shell if they are enclosed in
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double quotes. Users of the "csh" shell and derivatives will also need
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to quote the exclamation mark (!) with the backslash (i.e., \!) to
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properly run the examples listed above, even within single quotes.
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Versions of sed written for DOS invariably require double quotes
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("...") instead of single quotes to enclose editing commands.
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USE OF '\t' IN SED SCRIPTS: For clarity in documentation, we have used
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the expression '\t' to indicate a tab character (0x09) in the scripts.
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However, most versions of sed do not recognize the '\t' abbreviation,
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so when typing these scripts from the command line, you should press
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the TAB key instead. '\t' is supported as a regular expression
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metacharacter in awk, perl, and HHsed, sedmod, and GNU sed v3.02.80.
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VERSIONS OF SED: Versions of sed do differ, and some slight syntax
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variation is to be expected. In particular, most do not support the
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use of labels (:name) or branch instructions (b,t) within editing
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commands, except at the end of those commands. We have used the syntax
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which will be portable to most users of sed, even though the popular
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GNU versions of sed allow a more succinct syntax. When the reader sees
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a fairly long command such as this:
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sed -e '/AAA/b' -e '/BBB/b' -e '/CCC/b' -e d
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it is heartening to know that GNU sed will let you reduce it to:
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sed '/AAA/b;/BBB/b;/CCC/b;d' # or even
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sed '/AAA\|BBB\|CCC/b;d'
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In addition, remember that while many versions of sed accept a command
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like "/one/ s/RE1/RE2/", some do NOT allow "/one/! s/RE1/RE2/", which
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||||
contains space before the 's'. Omit the space when typing the command.
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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. Various scripts in this file were written
|
||||
or contributed by:
|
||||
|
||||
Al Aab <af137@freenet.toronto.on.ca> # "seders" list moderator
|
||||
Edgar Allen <era@sky.net> # various
|
||||
Yiorgos Adamopoulos <adamo@softlab.ece.ntua.gr>
|
||||
Dale Dougherty <dale@songline.com> # author of "sed & awk"
|
||||
Carlos Duarte <cdua@algos.inesc.pt> # author of "do it with sed"
|
||||
Eric Pement <pemente@northpark.edu> # author of this document
|
||||
Ken Pizzini <ken@halcyon.com> # author of GNU sed v3.02
|
||||
S.G. Ravenhall <stew.ravenhall@totalise.co.uk> # great de-html script
|
||||
Greg Ubben <gsu@romulus.ncsc.mil> # many contributions & much help
|
||||
-------------------------------------------------------------------------
|
||||
220
editors/sed_summary.htm
Normal file
220
editors/sed_summary.htm
Normal file
@ -0,0 +1,220 @@
|
||||
<html>
|
||||
|
||||
<head><title>Command Summary for sed (sed & awk, Second Edition)</title>
|
||||
</head>
|
||||
|
||||
<body>
|
||||
|
||||
<h2>Command Summary for sed</h2>
|
||||
|
||||
<dl>
|
||||
|
||||
<dt><b>: </b> <b> :</b><em>label</em></dt>
|
||||
<dd>Label a line in the script for the transfer of control by
|
||||
<b>b</b> or <b>t</b>.
|
||||
<em>label</em> 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.)
|
||||
</p></dd>
|
||||
|
||||
|
||||
<dt><b>=</b> [<em>address</em>]<b>=</b></dt>
|
||||
<dd>Write to standard output the line number of addressed line.</p></dd>
|
||||
|
||||
|
||||
<dt><b>a</b> [<em>address</em>]<b>a\</b></dt>
|
||||
<dd><em>text</em></p>
|
||||
|
||||
<p>Append <em>text</em>
|
||||
following each line matched by <em>address</em>. If
|
||||
<em>text</em> goes over more than one line, newlines
|
||||
must be "hidden" by preceding them with a backslash. The
|
||||
<em>text</em> will be terminated by the first
|
||||
newline that is not hidden in this way. The
|
||||
<em>text</em> 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.</p></dd>
|
||||
|
||||
|
||||
<dt><b>b</b> [<em>address1</em>[,<em>address2</em>]]<b>b</b>[<em>label</em>]</dt>
|
||||
<dd>Transfer control unconditionally (branch) to
|
||||
<b>:</b><em>label</em> elsewhere in
|
||||
script. That is, the command following the
|
||||
<em>label</em> is the next command applied to the
|
||||
current line. If no <em>label</em> is specified,
|
||||
control falls through to the end of the script, so no more commands
|
||||
are applied to the current line.</p></dd>
|
||||
|
||||
|
||||
<dt><b>c</b> [<em>address1</em>[,<em>address2</em>]]<b>c\</b></dt>
|
||||
<dd><em>text</em></p>
|
||||
|
||||
<p>Replace (change) the lines selected by the address with
|
||||
<em>text</em>. When a range of lines is specified,
|
||||
all lines as a group are replaced by a single copy of
|
||||
<em>text</em>. The newline following each line of
|
||||
<em>text</em> 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
|
||||
<em>text</em>).</p></dd>
|
||||
|
||||
|
||||
<dt><b>d</b> [<em>address1</em>[,<em>address2</em>]]<b>d</b></dt>
|
||||
<dd>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.</p></dd>
|
||||
|
||||
|
||||
<dt><b>D</b> [<em>address1</em>[,<em>address2</em>]]<b>D</b></dt>
|
||||
<dd>Delete first part (up to embedded newline) of multiline pattern space created
|
||||
by <b>N</b> 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 <b>d</b> command had been executed.</p></dd>
|
||||
|
||||
|
||||
<dt><b>g</b> [<em>address1</em>[,<em>address2</em>]]<b>g</b></dt>
|
||||
<dd>Copy (get) contents of hold space (see <b>h</b> or
|
||||
<b>H</b> command) into the pattern space, wiping out
|
||||
previous contents.</p></dd>
|
||||
|
||||
|
||||
<dt><b>G</b> [<em>address1</em>[,<em>address2</em>]]<b>G</b></dt>
|
||||
<dd>Append newline followed by contents of hold space (see
|
||||
<b>h</b> or <b>H</b> command) to contents of
|
||||
the pattern space. If hold space is empty, a newline is still
|
||||
appended to the pattern space.</p></dd>
|
||||
|
||||
|
||||
<dt><b>h</b> [<em>address1</em>[,<em>address2</em>]]<b>h</b></dt>
|
||||
<dd>Copy pattern space into hold space, a special temporary buffer.
|
||||
Previous contents of hold space are wiped out.</p></dd>
|
||||
|
||||
|
||||
<dt><b>H</b> [<em>address1</em>[,<em>address2</em>]]<b>H</b></dt>
|
||||
<dd>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.</p></dd>
|
||||
|
||||
|
||||
<dt><b>i</b> [<em>address1</em>]<b>i\</b></dt>
|
||||
<dd><em>text</em></p>
|
||||
|
||||
<p>Insert <em>text</em> before each line matched by
|
||||
<em>address</em>. (See <b>a</b> for
|
||||
details on <em>text</em>.)</p></dd>
|
||||
|
||||
|
||||
<dt><b>l</b> [<em>address1</em>[,<em>address2</em>]]<b>l</b></dt>
|
||||
<dd>List the contents of the pattern space, showing nonprinting characters
|
||||
as ASCII codes. Long lines are wrapped.</p></dd>
|
||||
|
||||
|
||||
<dt><b>n</b> [<em>address1</em>[,<em>address2</em>]]<b>n</b></dt>
|
||||
<dd>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 <b>n</b>
|
||||
instead of resuming at the top of the script.</p></dd>
|
||||
|
||||
|
||||
<dt><b>N</b> [<em>address1</em>[,<em>address2</em>]]<b>N</b></dt>
|
||||
<dd>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></dd>
|
||||
|
||||
|
||||
<dt><b>p</b> [<em>address1</em>[,<em>address2</em>]]<b>p</b></dt>
|
||||
<dd>Print the addressed line(s). Note that this can result in duplicate
|
||||
output unless default output is suppressed by using "#n" or
|
||||
the <span class="option">-n</span>
|
||||
|
||||
command-line option. Typically used before commands that change flow
|
||||
control (<b>d</b>, <b>n</b>,
|
||||
<b>b</b>) and might prevent the current line from being
|
||||
output.</p></dd>
|
||||
|
||||
|
||||
<dt><b>P</b> [<em>address1</em>[,<em>address2</em>]]<b>P</b></dt>
|
||||
<dd>Print first part (up to embedded newline) of multiline pattern space
|
||||
created by <b>N</b> command. Same as <b>p</b>
|
||||
if <b>N</b> has not been applied to a line.</p></dd>
|
||||
|
||||
|
||||
<dt><b>q</b> [<em>address</em>]<b>q</b></dt>
|
||||
<dd>Quit when <em>address</em> 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
|
||||
<b>a</b> or <b>r</b> commands.</p></dd>
|
||||
|
||||
|
||||
<dt><b>r</b> [<em>address</em>]<b>r</b> <em>file</em></dt>
|
||||
<dd>Read contents of <em>file</em> and append after the
|
||||
contents of the pattern space. Exactly one space must be put between
|
||||
<b>r</b> and the filename.</p></dd>
|
||||
|
||||
|
||||
<dt><b>s</b> [<em>address1</em>[,<em>address2</em>]]<b>s</b>/<em>pattern</em>/<em>replacement</em>/[<em>flags</em>]</dt>
|
||||
<dd>Substitute <em>replacement</em> for
|
||||
<em>pattern</em> on each addressed line. If pattern
|
||||
addresses are used, the pattern <b>//</b> represents the
|
||||
last pattern address specified. The following flags can be specified:</p>
|
||||
|
||||
<dl>
|
||||
|
||||
<dt><b>n</b></dt>
|
||||
<dd>Replace <em>n</em>th instance of
|
||||
/<em>pattern</em>/ on each addressed line.
|
||||
<em>n</em> is any number in the range 1 to 512, and
|
||||
the default is 1.</p></dd>
|
||||
|
||||
<dt><b>g</b></dt>
|
||||
<dd>Replace all instances of /<em>pattern</em>/ on each
|
||||
addressed line, not just the first instance.</p></dd>
|
||||
|
||||
<dt><b>p</b></dt>
|
||||
<dd>Print the line if a successful substitution is done. If several
|
||||
successful substitutions are done, multiple copies of the line will be
|
||||
printed.</p></dd>
|
||||
|
||||
<dt><b>w</b> <em>file</em></dt>
|
||||
<dd>Write the line to <em>file</em> if a replacement
|
||||
was done. A maximum of 10 different <em>files</em> can be opened.</p></dd>
|
||||
|
||||
</dl>
|
||||
|
||||
</dd>
|
||||
|
||||
|
||||
<dt><b>t</b> [<em>address1</em>[,<em>address2</em>]]<b>t </b>[<em>label</em>]</dt>
|
||||
<dd>Test if successful substitutions have been made on addressed lines,
|
||||
and if so, branch to line marked by :<em>label</em>.
|
||||
(See <b>b</b> and <b>:</b>.) If label is not
|
||||
specified, control falls through to bottom of script.</p></dd>
|
||||
|
||||
|
||||
<dt><b>w</b> [<em>address1</em>[,<em>address2</em>]]<b>w</b> <em>file</em></dt>
|
||||
<dd>Append contents of pattern space to <em>file</em>.
|
||||
This action occurs when the command is encountered rather than when
|
||||
the pattern space is output. Exactly one space must separate the
|
||||
<b>w</b> 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.</p></dd>
|
||||
|
||||
|
||||
<dt><b>x</b> [<em>address1</em>[,<em>address2</em>]]<b>x</b></dt>
|
||||
<dd>Exchange contents of the pattern space with the contents of the hold
|
||||
space.</p></dd>
|
||||
|
||||
|
||||
<dt><b>y</b> [<em>address1</em>[,<em>address2</em>]]<b>y</b>/<em>abc</em>/<em>xyz</em>/</dt>
|
||||
<dd>Transform each character by position in string
|
||||
<em>abc</em> to its equivalent in string
|
||||
<em>xyz</em>.</p></dd>
|
||||
|
||||
|
||||
</dl>
|
||||
Loading…
Reference in New Issue
Block a user