diff options
author | Denis Vlasenko <vda.linux@googlemail.com> | 2007-11-13 20:13:31 +0300 |
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committer | Denis Vlasenko <vda.linux@googlemail.com> | 2007-11-13 20:13:31 +0300 |
commit | 72cc9641f80b6981cc97fd66feb8d5842ea5ed03 (patch) | |
tree | c8bb972fb90b451faae4dfe60cd3f33a77d40bff /editors | |
parent | 40276648ab31822068c3408ae43a5ecaafd03a5c (diff) |
add sed mini-doc
Diffstat (limited to 'editors')
-rw-r--r-- | editors/sed1line.txt | 425 | ||||
-rw-r--r-- | editors/sed_summary.htm | 220 |
2 files changed, 645 insertions, 0 deletions
diff --git a/editors/sed1line.txt b/editors/sed1line.txt new file mode 100644 index 000000000..11a2e36be --- /dev/null +++ b/editors/sed1line.txt @@ -0,0 +1,425 @@ +http://www.student.northpark.edu/pemente/sed/sed1line.txt +------------------------------------------------------------------------- +HANDY ONE-LINERS FOR SED (Unix stream editor) Apr. 26, 2004 +compiled by Eric Pement - pemente[at]northpark[dot]edu version 5.4 +Latest version of this file is usually at: + http://sed.sourceforge.net/sed1line.txt + http://www.student.northpark.edu/pemente/sed/sed1line.txt +This file is also available in Portuguese at: + http://www.lrv.ufsc.br/wmaker/sed_ptBR.html + +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$//' # in bash/tcsh, press Ctrl-V then Ctrl-M + sed 's/\x0D$//' # gsed 3.02.80, but top script is easier + + # 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 + + # IN DOS ENVIRONMENT: convert Unix newlines (LF) to DOS format + sed "s/$//" # method 1 + sed -n p # method 2 + + # IN DOS ENVIRONMENT: convert DOS newlines (CR/LF) to Unix format + # Can only be done with UnxUtils sed, version 4.0.7 or higher. + # Cannot be done with other DOS versions of sed. Use "tr" instead. + sed "s/\r//" infile >outfile # UnxUtils sed v4.0.7 or higher + tr -d \r <infile >outfile # GNU tr version 1.22 or higher + + # delete leading whitespace (spaces, tabs) from front of each line + # aligns all text flush left + sed 's/^[ \t]*//' # see note on '\t' at end of file + + # delete trailing whitespace (spaces, tabs) from end of each line + sed 's/[ \t]*$//' # 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 ':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 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 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 v1.5 + + # 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 + + # 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. 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 +------------------------------------------------------------------------- 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 @@ +<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> |