editors/sed1line.txt - fp2-dev/platform/external/busybox - Gitiles

 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
 -------------------------------------------------------------------------
	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
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