diff --git a/sed.spec b/sed.spec index bf608f7..011be67 100644 --- a/sed.spec +++ b/sed.spec @@ -5,10 +5,11 @@ Summary: A GNU stream text editor. Name: sed Version: 4.1.2 -Release: 1 +Release: 2 Copyright: GPL Group: Applications/Text Source0: ftp://ftp.gnu.org/pub/gnu/sed/sed-%{version}.tar.gz +Source1: http://sed.sourceforge.net/sedfaq.txt Prereq: /sbin/install-info Prefix: %{_prefix} Buildroot: %{_tmppath}/%{name}-root @@ -29,6 +30,7 @@ specified in a script file or from the command line. %build %configure --without-included-regex make %{_smp_mflags} +install -m 644 %{SOURCE1} sedfaq.txt echo ====================TESTING========================= make check @@ -61,6 +63,9 @@ rm -rf ${RPM_BUILD_ROOT} %{_mandir}/man*/* %changelog +* Sat Oct 2 2004 Jakub Jelinek 4.1.2-2 +- add sedfaq.txt to %{_docdir} (#16202) + * Mon Aug 23 2004 Florian La Roche - update to 4.1.2 diff --git a/sedfaq.txt b/sedfaq.txt new file mode 100644 index 0000000..33ac26d --- /dev/null +++ b/sedfaq.txt @@ -0,0 +1,3964 @@ + +Archive-Name: editor-faq/sed +Posting-Frequency: irregular +Last-modified: 10 March 2003 +Version: 015 +URL: http://sed.sourceforge.net/sedfaq.html +Maintainer: Eric Pement (pemente@northpark.edu) + + THE SED FAQ + + Frequently Asked Questions about + sed, the stream editor + +CONTENTS + +1. GENERAL INFORMATION +1.1. Introduction - How this FAQ is organized +1.2. Latest version of the sed FAQ +1.3. FAQ revision information +1.4. How do I add a question/answer to the sed FAQ? +1.5. FAQ abbreviations +1.6. Credits and acknowledgements +1.7. Standard disclaimers + +2. BASIC SED +2.1. What is sed? +2.2. What versions of sed are there, and where can I get them? + +2.2.1. Free versions + +2.2.1.1. Unix platforms +2.2.1.2. OS/2 +2.2.1.3. Microsoft Windows (Win3x, Win9x, WinNT, Win2K) +2.2.1.4. MS-DOS +2.2.1.5. CP/M +2.2.1.6. Macintosh v8 or v9 + +2.2.2. Shareware and Commercial versions + +2.2.2.1. Unix platforms +2.2.2.2. OS/2 +2.2.2.3. Windows 95/98, Windows NT, Windows 2000 +2.2.2.4. MS-DOS + +2.3. Where can I learn to use sed? + +2.3.1. Books +2.3.2. Mailing list +2.3.3. Tutorials, electronic text +2.3.4. General web and ftp sites + +3. TECHNICAL +3.1. More detailed explanation of basic sed +3.1.1. Regular expressions on the left side of "s///" +3.1.2. Escape characters on the right side of "s///" +3.1.3. Substitution switches +3.2. Common one-line sed scripts. How do I . . . ? + + - double/triple-space a file? + - convert DOS/Unix newlines? + - delete leading/trailing spaces? + - do substitutions on all/certain lines? + - delete consecutive blank lines? + - delete blank lines at the top/end of the file? + +3.3. Addressing and address ranges +3.4. Address ranges in GNU sed and HHsed +3.5. Debugging sed scripts +3.6. Notes about s2p, the sed-to-perl translator +3.7. GNU/POSIX extensions to regular expressions + +4. EXAMPLES + ONE-CHARACTER QUESTIONS +4.1. How do I insert a newline into the RHS of a substitution? +4.2. How do I represent control-codes or non-printable characters? +4.3. How do I convert files with toggle characters, like +this+, + to look like [i]this[/i]? + + CHANGING STRINGS +4.10. How do I perform a case-insensitive search? +4.11. How do I match only the first occurrence of a pattern? +4.12. How do I parse a comma-delimited (CSV) data file? +4.13. How do I handle fixed-length, columnar data? +4.14. How do I commify a string of numbers? +4.15. How do I prevent regex expansion on substitutions? +4.16. How do I convert a string to all lowercase or capital letters? + + CHANGING BLOCKS (consecutive lines) +4.20. How do I change only one section of a file? +4.21. How do I delete or change a block of text if the block contains + a certain regular expression? +4.22. How do I locate a paragraph of text if the paragraph contains a + certain regular expression? +4.23. How do I match a block of specific consecutive lines? +4.23.1. Try to use a "/range/, /expression/" +4.23.2. Try to use a "multi-line\nexpression" +4.23.3. Try to use a block of "literal strings" +4.24. How do I address all the lines between RE1 and RE2, excluding the lines themselves? +4.25. How do I join two lines if line #1 ends in a [certain string]? +4.26. How do I join two lines if line #2 begins in a [certain string]? +4.27. How do I change all paragraphs to long lines? + + SHELL AND ENVIRONMENT +4.30. How do I read environment variables with sed ... +4.31.1. ... on Unix platforms? +4.31.2. ... on MS-DOS or 4DOS platforms? +4.32. How do I export or pass variables back into the environment ... +4.32.1. ... on Unix platforms? +4.32.2. ... on MS-DOS or 4DOS platforms? +4.33. How do I handle shell quoting in sed? + + FILES, DIRECTORIES, AND PATHS +4.40. How do I read (insert/add) a file at the top of a textfile? +4.41. How do I make substitutions in every file in a directory, or + in a complete directory tree? +4.41.1. ... ssed solution +4.41.2. ... Unix solution +4.41.3. ... DOS solution +4.42. How do I replace "/some/UNIX/path" in a substitution? +4.43. How do I replace "C:\SOME\DOS\PATH" in a substitution? +4.44. How do I emulate file-includes, using sed? + +5. WHY ISN'T THIS WORKING? +5.1. Why don't my variables like $var get expanded in my sed script? +5.2. I'm using 'p' to print, but I have duplicate lines sometimes. +5.3. Why does my DOS version of sed process a file part-way through + and then quit? +5.4. My RE isn't matching/deleting what I want it to. (Or, "Greedy vs. + stingy pattern matching") +5.5. What is CSDPMI*B.ZIP and why do I need it? +5.6. Where are the man pages for GNU sed? +5.7. How do I tell what version of sed I am using? +5.8. Does sed issue an exit code? +5.9. The 'r' command isn't inserting the file into the text. +5.10. Why can't I match or delete a newline using the \n escape + sequence? Why can't I match 2 or more lines using \n? +5.11. My script aborts with an error message, "event not found". + +6. OTHER ISSUES +6.1. I have a problem that stumps me. Where can I get help? +6.2. How does sed compare with awk, perl, and other utilities? +6.3. When should I use sed? +6.4. When should I NOT use sed? +6.5. When should I ignore sed and use Awk or Perl instead? +6.6. Known limitations among sed versions +6.7. Known incompatibilities between sed versions + +6.7.1. Issuing commands from the command line +6.7.2. Using comments (prefixed by the '#' sign) +6.7.3. Special syntax in REs +6.7.4. Word boundaries +6.7.5. Commands which operate differently + +7. KNOWN BUGS AMONG SED VERSIONS +7.1. ssed v3.59 +7.2. GNU sed v4.0 - v4.0.5 +7.3. GNU sed v3.02.80 +7.4. GNU sed v3.02 +7.5. GNU sed v2.05 +7.6. GNU sed v1.18 +7.7. GNU sed v1.03 +7.8. sed v1.6 (Briscoe) +7.9. sed v1.5 (Helman) +7.10. sedmod v1.0 (Chen) +7.11. HP-UX sed +7.12. SunOS sed v4.1 +7.13. SunOS sed v5.6 +7.14. Ultrix sed v4.3 +7.15. Digital Unix sed + + +------------------------------ + +1. GENERAL INFORMATION + +1.1. Introduction - How this FAQ is organized + + This FAQ is organized to answer common (and some uncommon) + questions about sed, quickly. If you see a term or abbreviation in + the examples that seems unclear, see if the term is defined in + section 1.5. If not, send your comment to pemente[at]northpark.edu. + +1.2. Latest version of the sed FAQ + + The newest version of the sed FAQ is usually here: + + http://sed.sourceforge.net/sedfaq.html (HTML version) + http://sed.sourceforge.net/sedfaq.txt (plain text) + http://www.student.northpark.edu/pemente/sed/sedfaq.html + http://www.student.northpark.edu/pemente/sed/sedfaq.txt + http://www.faqs.org/faqs/editor-faq/sed + ftp://rtfm.mit.edu/pub/faqs/editor-faq/sed + + Another FAQ file on sed by a different author can be found here: + + http://www.dreamwvr.com/sed-info/sed-faq.html + +1.3. FAQ revision information + + In the plaintext version, changes are shown by a vertical bar (|) + placed in column 78 of the affected lines. To remove the vertical + bars (use double quotes for MS-DOS): + + sed 's/ *|$//' sedfaq.txt > sedfaq2.txt + + In the HTML version, vertical bars do not appear. New or altered + portions of the FAQ are indicated by printing in dark blue type. + + In the text version, words needing emphasis may be surrounded by + the underscore '_' or the asterisk '*'. In the HTML version, these + are changed to italics and boldface, respectively. + +1.4. How do I add a question/answer to the sed FAQ? + + Word your question briefly and send it to pemente[at]northpark.edu, + indicating your proposed change. We'll post it on the sed-users + mailing list (see section 2.3.2) and discuss it there. If it's + good, your contribution will be added to the next edition. + +1.5. FAQ abbreviations + + files = one or more filenames, separated by whitespace + gsed = GNU sed + ssed = super-sed + RE = Regular Expressions supported by sed + LHS = the left-hand side ("find" part) of "s/find/repl/" command + RHS = the right-hand side ("replace" part) of "s/find/repl/" cmd + nn+ = version _nn_ or higher (e.g., "15+" = version 1.5 and above) + + files: "files" stands for one or more filenames entered on the + command line. The names may include any wildcards your shell + understands (such as ``zork*'' or ``Aug[4-9].let''). Sed will + process each filename passed to it by the shell. + + RE: For details on regular expressions, see section 3.1.1., below. + +1.6. Credits and acknowledgements + + Many of the ideas for this FAQ were taken from the Awk FAQ: + http://www.faqs.org/faqs/computer-lang/awk/faq/ + ftp://rtfm.mit.edu/pub/usenet/comp.lang.awk/faq + + and from the old Perl FAQ: + http://www.perl.com/doc/FAQs/FAQ/oldfaq-html/index.html + + The following individuals have contributed significantly to this + document, and have provided input and wording suggestions for + questions, answers, and script examples. Credit goes to these + contributors (in alphabetical order by last name): + + Al Aab, Yiorgos Adamopoulos, Paolo Bonzini, Walter Briscoe, Jim + Dennis, Carlos Duarte, Otavio Exel, Sven Guckes, Aurelio Jargas, + Mark Katz, Toby Kelsey, Eric Pement, Greg Pfeiffer, Ken Pizzini, + Niall Smart, Simon Taylor, Peter Tillier, Greg Ubben, Laurent + Vogel. + +1.7. Standard disclaimers + + While a serious attempt has been made to ensure the accuracy of the + information presented herein, the contributors and maintainers of + this document do not claim the absence of errors and make no + warranties on the information provided. If you notice any mistakes, + please let us know so we can fix it. + +------------------------------ + +2. BASIC SED + +2.1. What is sed? + + "sed" stands for Stream EDitor. Sed is a non-interactive editor, + written by the late Lee E. McMahon in 1973 or 1974. A brief history + of sed's origins may be found in an early history of the Unix + tools, at . + + Instead of altering a file interactively by moving the cursor on + the screen (as with a word processor), the user sends a script of + editing instructions to sed, plus the name of the file to edit (or + the text to be edited may come as output from a pipe). In this + sense, sed works like a filter -- deleting, inserting and changing + characters, words, and lines of text. Its range of activity goes + from small, simple changes to very complex ones. + + Sed reads its input from stdin (Unix shorthand for "standard + input," i.e., the console) or from files (or both), and sends the + results to stdout ("standard output," normally the console or + screen). Most people use sed first for its substitution features. + Sed is often used as a find-and-replace tool. + + sed 's/Glenn/Harold/g' oldfile >newfile + + will replace every occurrence of "Glenn" with the word "Harold", + wherever it occurs in the file. The "find" portion is a regular + expression ("RE"), which can be a simple word or may contain + special characters to allow greater flexibility (for example, to + prevent "Glenn" from also matching "Glennon"). + + My very first use of sed was to add 8 spaces to the left side of a + file, so when I printed it, the printing wouldn't begin at the + absolute left edge of a piece of paper. + + sed 's/^/ /' myfile >newfile # my first sed script + sed 's/^/ /' myfile | lp # my next sed script + + Then I learned that sed could display only one paragraph of a file, + beginning at the phrase "and where it came" and ending at the + phrase "for all people". My script looked like this: + + sed -n '/and where it came/,/for all people/p' myfile + + Sed's normal behavior is to print (i.e., display or show on screen) + the entire file, including the parts that haven't been altered, + unless you use the -n switch. The "-n" stands for "no output". This + switch is almost always used in conjunction with a 'p' command + somewhere, which says to print only the sections of the file that + have been specified. The -n switch with the 'p' command allow for + parts of a file to be printed (i.e., sent to the console). + + Next, I found that sed could show me only (say) lines 12-18 of a + file and not show me the rest. This was very handy when I needed to + review only part of a long file and I didn't want to alter it. + + # the 'p' stands for print + sed -n 12,18p myfile + + Likewise, sed could show me everything else BUT those particular + lines, without physically changing the file on the disk: + + # the 'd' stands for delete + sed 12,18d myfile + + Sed could also double-space my single-spaced file when it came time + to print it: + + sed G myfile >newfile + + If you have many editing commands (for deleting, adding, + substituting, etc.) which might take up several lines, those + commands can be put into a separate file and all of the commands in + the file applied to file being edited: + + # 'script.sed' is the file of commands + # 'myfile' is the file being changed + sed -f script.sed myfile # 'script.sed' is the file of commands + + It is not our intention to convert this FAQ file into a full-blown + sed tutorial (for good tutorials, see section 2.3). Rather, we hope + this gives the complete novice a few ideas of how sed can be used. + +2.2. What versions of sed are there, and where can I get them? + +2.2.1. Free versions + + Note: "Free" does not mean "public domain" nor does it necessarily + mean you will never be charged for it. All versions of sed in this + section except the CP/M versions are based on the GNU general + public license and are "free software" by that standard (for + details, see http://www.gnu.org/philosophy/free-sw.html). This + means you can get the source code and develop it further. + + At the URLs listed in this category, sed binaries or source code + can be downloaded and used without fees or license payments. + +2.2.1.1. Unix platforms + + ssed v3.60 + ssed is the version recommended by the FAQ maintainers, since it + shares the same codebase with GNU sed, has the most options, and is + free software (you can get the source). Though there were earlier + version of ssed distributed, sites for these are not being listed. + + http://sed.sourceforge.net/grabbag/ssed + http://freshmeat.net/project/sed/ + + GNU sed v4.0.5 + This is the latest official version of GNU sed. It offers in-place + text replacement as an option switch. + + ftp://ftp.gnu.org/pub/gnu/sed/sed-4.0.5.tar.gz + http://freshmeat.net/project/sed + + BSD multi-byte sed (Japanese) + Based on the latest version of GNU sed, which supports multi-byte + characters. + + ftp://ftp1.freebsd.org/pub/FreeBSD/FreeBSD-stable/packages/Latest/ja-sed.tgz + + GNU sed v3.02.80 + An alpha test release which was the base for the development of + ssed and GNU sed v4.0. + + ftp://alpha.gnu.org/pub/gnu/sed/sed-3.02.80.tar.gz + + GNU sed v3.02a + Interim version with most features of GNU sed v3.02.80. + + GNU sed v3.02 + ftp://ftp.gnu.org/pub/gnu/sed/sed-3.02.tar.gz + + Precompiled versions: + + GNU sed v3.02-8 + source code and binaries for Debian GNU/Linux + + http://www.debian.org/Packages/stable/base/sed.html + + For some time, the GNU project used Eric S. + Raymond's version of sed (ESR sed v1.1), but eventually dropped it + because it had too many built-in limits. In 1991 Howard Helman + modified the GNU/ESR sed and produced a flexible version of sed + v1.5 available at several sites (Helman's version permitted things + like \<...\> to delimit word boundaries, \xHH to enter hex code and + \n to indicate newlines in the replace string). This version did + not catch on with the GNU project and their version of sed has + moved in a similar but different direction. + + sed v1.3, by Eric Steven Raymond (released 4 June 1998) + http://catb.org/~esr/sed-1.3.tar.gz + + Eric Raymond wrote one of the earliest + versions of sed. On his website which + also distributes many freeware utilities he has written or worked + on, he describes sed v1.1 this way: + + "This is the fast, small sed originally distributed in the GNU + toolkit and still distributed with Minix. The GNU people ditched it + when they built their own sed around an enhanced regex package -- + but it's still better for some uses (in particular, faster and less + memory-intensive)." (Version 1.3 fixes an unidentified bug and adds + the L command to hexdump the current pattern space.) + +2.2.1.2. OS/2 + + GNU sed v3.02.80 + http://www2s.biglobe.ne.jp/~vtgf3mpr/gnu/sed.htm + + GNU sed v3.02 + http://hobbes.nmsu.edu/pub/os2/util/file/sed-3_02-r2-bin.zip # binaries + http://hobbes.nmsu.edu/pub/os2/util/file/sed-3_02-r2.zip # source + +2.2.1.3. Microsoft Windows (Win3x, Win9x, WinNT, Win2K) + + GNU sed v4.0.5 + 32-bit binaries and docs. Precompiled versions not available (yet). + + GNU sed v3.02.80 + 32-bit binaries and docs, using DJGPP compiler. For details on new + features, see Unix section, above. + + http://www.student.northpark.edu/pemente/sed/sed3028a.zip # DOS binaries + ftp://alpha.gnu.org/pub/gnu/sed/sed-3.02.80.tar.gz # source + ftp://ftp.simtel.net/pub/simtelnet/gnu/djgpp/v2gnu/sed3028b.zip # binaries + ftp://ftp.simtel.net/pub/simtelnet/gnu/djgpp/v2gnu/sed3028d.zip # docs + ftp://ftp.simtel.net/pub/simtelnet/gnu/djgpp/v2gnu/sed3028s.zip # source + + GNU sed v2.05 + 32-bit binaries, no docs. Requires 80386 DX (SX will not run) and + must be run in a DOS window or in a full screen DOS session under + Microsoft Windows. Will not run in MS-DOS mode (outside Win/Win95). + We recommend using the latest version of GNU sed. + http://www.simtel.net/pub/win95/prog/gsed205b.zip + ftp://ftp.cdrom.com/pub/simtelnet/win95/prog/gsed205b.zip + + GNU sed v1.03 + modified by Frank Whaley. + + This version was part of the "Virtually UN*X" toolset, hosted by + itribe.net; that website is now closed. Gsed v1.03 supported Win9x + long filenames, as well as hex, decimal, binary, and octal + character representations. + + The Cygwin toolkit: + http://www.cygwin.com + + Formerly know as "GNU-Win32 tools." According to their home page, + "The Cygwin tools are Win32 ports of the popular GNU development + tools for Windows NT, 95 and 98. They function through the use of + the Cygwin library which provides a UNIX-like API on top of the + Win32 API." The version of sed used is GNU sed v3.02. + + Minimalist GNU for Windows (MinGW): + http://www.mingw.org + http://mingw.sourceforge.net + + According to their home page, "MinGW ('Minimalist GNU for Windows') + refers to a set of runtime headers, used in building a compiler + system based on the GNU GCC and binutils projects. It compiles and + links code to be run on Win32 platforms ... MinGW uses Microsoft + runtime libraries, distributed with the Windows operating system." + The version of sed used is GNU sed v3.02. + + sed v1.5 (a/k/a HHsed), by Howard Helman + Compiled with Mingw32 for 32-bit environments described above. This + version should support Win95 long filenames. + http://www.dbnet.ece.ntua.gr/~george/sed/OLD/sed15.exe + http://www.student.northpark.edu/pemente/sed/sed15exe.zip + +2.2.1.4. MS-DOS + + sed v1.6 (from HHsed), by Walter Briscoe + + This is a forthcoming version, now in beta testing, but with many + new features. It corrects all the bugs in sed v1.5, and adds the + best features of sedmod v1.0 (below). It is available in 16-bit and + 32-bit compiled versions for MS-DOS. Sorry, no URLs available yet. + + sed v1.5 (a/k/a HHsed), by Howard Helman + uncompiled source code (Turbo C) + ftp://ftp.simtel.net/pub/simtelnet/msdos/txtutl/sed15.zip + ftp://ftp.cdrom.com/pub/simtelnet/msdos/txtutl/sed15.zip + + DOS executable and documentation + ftp://ftp.simtel.net/pub/simtelnet/msdos/txtutl/sed15x.zip + ftp://ftp.cdrom.com/pub/simtelnet/msdos/txtutl/sed15x.zip + + sedmod v1.0, by Hern Chen + http://www.ptug.org/sed/SEDMOD10.ZIP + http://www.student.northpark.edu/pemente/sed/sedmod10.zip + ftp://garbo.uwasa.fi/pc/unix/sedmod10.zip + + GNU sed v3.02.80 + See section 2.2.1.3 ("Microsoft Windows"), above. + + GNU sed v2.05 + Does not run under MS-DOS. + + GNU sed v1.18 + 32-bit binaries and source, using DJGPP compiler. Requires 80386 SX + or better. Also requires 3 CWS*.EXE extenders on the path. See + section 5.5 ("What is CSDPMI*B.ZIP and why do I need it?"), below. + We recommend using a newer version of GNU sed. + http://www.simtel.net/pub/simtelnet/gnu/djgpp/v2gnu/sed118b.zip + ftp://ftp.cdrom.com/pub/simtelnet/gnu/djgpp/v2gnu/sed118b.zip + http://www.simtel.net/pub/simtelnet/gnu/djgpp/v2gnu/sed118s.zip + ftp://ftp.cdrom.com/pub/simtelnet/gnu/djgpp/v2gnu/sed118s.zip + + GNU sed v1.06 + 16-bit binaries and source. Should run under any MS-DOS system. + http://www.simtel.net/pub/gnu/gnuish/sed106.zip + ftp://ftp.cdrom.com/pub/simtelnet/gnu/gnuish/sed106.zip + +2.2.1.5. CP/M + + ssed v2.2, by Chuck A. Forsberg + + Written for CP/M, ssed (for "small/stupid stream editor) supports + only the a(ppend), c(hange), d(elete) and i(nsert) options, and + apparently doesn't support regular expressions. A -u switch will + "unsqueeze" compressed files and was used mainly in conjunction + with DIF.COM for source code maintenance. (file: ssed22.lbr) + + change, by Michael M. Rubenstein + + Rubenstein released a version of sed called CHANGE.COM (the + TTOOLS.LBR archive member CHANGE.CZM is a "crunched" file). + CHANGE.COM supports full RE's except grouping and backreferences, + and its only function is global substitution. (file: ttools.lbr) + +2.2.1.6. Macintosh v8 or v9 + + Since sed is a command-line utility, it is not customary to think + of sed being used on a Mac. Nonetheless, the following instructions + from Aurelio Jargas describe the process for running sed on MacOS + version version 8 or 9. + + (1) Download and install the Apple DiskCopy application + + ftp://ftp.apple.com/developer/Development_Kits + + (2) Download and install Apple MPW + + ftp://ftp.apple.com/developer/Tool_Chest/Core_Mac_OS_Tools/MPW_etc./ + + (3) Download and expand Matthias Neeracher's GNU sed for MPW. (They + seem to have misnumbered the sed filename.) + + ftp://sunsite.cnlab-switch.ch/software/platform/macos/src/mpw_c/sed-2.03.sit.bin + + (4) Enter the sed-3.02 directory and doubleclick the 'sed' file + + (5) MPW Shell will open up. It will be a command window instead of + a command line, but sed should work as expected. For example: + + echo aa | sed 's/a/Z/g' + + Note that ENTER is different from RETURN on an iMac. Apple *also* + has its own version of sed on MPW, called "StreamEdit", with a + syntax fairly similar to that of normal sed. + +2.2.2. Shareware and Commercial versions + +2.2.2.1. Unix platforms + + [ Additional information needed. ] + +2.2.2.2. OS/2 + + Hamilton Labs: + http://www.hamiltonlabs.com/cshell.htm + + A sizable set of Unix/C shell utilities designed for OS/2. Price is + $350 in the US, $395 elsewhere, with FedEx shipping, unconditional + guarantee, unlimited support and free updates. A demo version of + the suite can be downloaded from this site, but a stand-alone copy + of sed is not available. + +2.2.2.3. Windows 95/98, Windows NT, Windows 2000 + + Hamilton Labs: + http://www.hamiltonlabs.com/cshell.htm + + A sizable set of Unix/C shell utilities designed for Win9x, WinNT, + and Win2K. Price is $350 in the US, $395 elsewhere, with FedEx + shipping, unconditional guarantee, unlimited support and free + updates. A demo version of the suite can be downloaded from this + site, but a stand-alone copy of sed is not available. + + Interix: + http://www.interix.com + + Interix (formerly known as OpenNT) is advertised as "a complete + UNIX system environment running natively on Microsoft Windows NT", + and is licensed and supported by Softway Systems. It offers over + 200 Unix utilities, and supports Unix shells, sockets, networking, + and more. A single-user edition runs about $200. A free demo or + evaluation copy will run for 31 days and then quit; to continue + using it, you must purchase the commercial version. + + MKS NuTCRACKER Professional + http://www.datafocus.com/products/nutc/ + + A different, yet related product line offered by MKS (Mortice Kern + Systems, below); the awkward spelling "NuTCRACKER" is intentional. + Various packages offer hundreds of Unix utilities for Win32 + environments. Sed is not available as a separate product. + + UnixDos: + http://www.unixdos.com + + UnixDos is a suite of 82 Unix utilities ported over to the Windows + environments. There are 16-bit versions for Win3.x and 32-bit + versions for WinNT/Win95. It is distributed as uncrippled shareware + for the first 30 days. After the test period, the utilities will + not run and you must pay the registration fee of $50. + + Their version of sed supports "\n" in the RHS of expressions, and + increases the length of input lines to 10,000 characters. By + special arrangement with the owners, persons who want a licensed + version of sed *only* (without the other utilities) may pay a + license fee of $10. + + U/WIN: + http://www.research.att.com/sw/tools/uwin/ + + U/WIN is a suite of Unix utilities created for WinNT and Win95 + systems. It is owned by AT&T, created by David Korn (author of the + Unix korn shell), and is freely distributed only to educational + institutions, AT&T employees, or certain researchers; all others + must pay a fee after a 90-day evaluation period expires. U/WIN + operates best with the NTFS (WinNT file system) but will run in + degraded mode with the FAT file system and in further degraded mode + under Win95. A minimal installation takes about 25 to 30 megs of + disk space. Sed is not available as a separate file for download, + but comes with the suite. + +2.2.2.4. MS-DOS + + Mix C/Utilities Toolchest + http://www.mixsoftware.com/product/utility.htm + + According to their web page, "The C/Utilities Toolchest adds over + 40 powerful UNIX utilities to your MS-DOS operating system. The + result is an environment very similar to UNIX operating systems, + yet 100% compatible with MS-DOS programs and commands." The + toolchest costs $19.95, with source code available for an + additional fee. Mix C's version of sed is not available separately. + + MKS (Mortice Kern Systems) Toolkit + http://www.mks.com + + Sed comes bundled with the MKS Toolkit, which is distributed only + as commercial software; it is not available separately. + + Thompson Automation Software + http://www.tasoft.com + + The Thompson Toolkit contains over 100 familiar Unix utilities, + including a version of the Unix Korn shell. It runs under MS-DOS, + OS/2, Win3.x, Win9x, and WinNT. Sed is one of the utilities, though + Thompson is better known for its version of awk for DOS, TAWK. The + toolkit runs about $150; sed is not available separately. + +2.3. Where can I learn to use sed? + +2.3.1. Books + + _Sed & Awk, 2d edition_, by Dale Dougherty & Arnold Robbins + (Sebastopol, Calif: O'Reilly and Associates, 1997) + ISBN 1-56592-225-5 + http://www.oreilly.com/catalog/sed2/noframes.html + + About 40 percent of this book is devoted to sed, and maybe 50 + percent is devoted to awk. The other 10 percent covers regexes and + concepts common to both tools. If you prefer hard copy, this is + definitely the best single place to learn to use sed, including its + advanced features. + + The first edition is also very useful. Several typos crept into the + first printing of the first edition (though if you follow the + tutorials closely, you'll recognize them right away). A list of + errors from the first printing of _sed & awk_ is available at + , and errors in + the 2nd are at , + though most of these were corrected in later printings. The second + edition tells how POSIX standards have affected these tools and + covers the popular GNU versions of sed and awk. Price is about (US) + $30.00 + + ----- + + _Mastering Regular Expressions, 2d ed.,_ by Jeffrey E. F. Friedl + (Sebastopol, Calif: O'Reilly and Associates, 2002) + ISBN 0-596-00289-0 + http://regex.info + http://www.oreilly.com/catalog/regex2/ + http://public.yahoo.com/~jfriedl/regex/ (for the first edition) + + Knowing how to use "regular expressions" is essential to effective + use of most Unix tools. This book focuses on how regular + expressions can be best implemented in utilities such as perl, vi, + emacs, and awk, but also touches on sed as well. Friedl's home page + (above) gives links to other sites which help students learn to + master regular expressions. His site also gives a Perl script for + determining a syntactically valid e-mail address, using regexes: + + http://public.yahoo.com/~jfriedl/regex/code.html + + ----- + + _Awk und Sed_, by Helmut Herold. + (Bonn: Addison-Wesley, 1994; 288 pages) + 2nd edition to be released in March 2003 + ISBN 3-8273-2094-1 + http://www.addison-wesley.de/main/main.asp?page=home/bookdetails&ProductID=37214 + +2.3.2. Mailing list + + If you are interested in learning more about sed (its syntax, using + regular expressions, etc.) you are welcome to subscribe to a + sed-oriented mailing list. In fact, there are two mailing lists + about sed: one in English named "sed-users", moderated by Sven + Guckes; and one in Portuguese named "sed-BR" (for sed-Brazil), + moderated by Aurelio Marinho Jargas. The average volume of mail for + "sed-users" is about 35 messages a week; the average volume of mail + for "sed-BR" is about 15 messages a week. + + sed-BR mailing list: http://br.groups.yahoo.com/group/sed-br/ + sed-users mailing list: http://groups.yahoo.com/group/sed-users/ + + To subscribe to sed-users, send a blank message to: + + sed-users-subscribe@yahoogroups.com + + To unsubscribe from sed-users, send a blank message to: + + sed-users-unsubscribe@yahoogroups.com + +2.3.3. Tutorials, electronic text + + The original users manual for sed, by Lee E. McMahon, from the + 7th edition UNIX Manual (1978), with the classic "Kubla Khan" + example and tutorial, in formatted text format: + http://sed.sourceforge.net/grabbag/tutorials/sed_mcmahon.txt + + The source code to the preceding manual. Use "troff -ms sed" to + print this file properly: + http://plan9.bell-labs.com/7thEdMan/vol2/sed + http://cm.bell-labs.com/7thEdMan/vol2/sed + + "Do It With Sed", by Carlos Duarte + http://www.dbnet.ece.ntua.gr/~george/sed/OLD/sedtut_1.html + + "Sed: How to use sed, a special editor for modifying files + automatically", by Bruce Barnett and General Electric Company + http://www.grymoire.com/Unix/Sed.html + + U-SEDIT2.ZIP, by Mike Arst (16 June 1990) + ftp://ftp.cs.umu.se/pub/pc/u-sedit2.zip + ftp://ftp.uni-stuttgart.de/pub/systems/msdos/util/unixlike/u-sedit2.zip + ftp://sunsite.icm.edu.pl/vol/wojsyl/garbo/pc/editor/u-sedit2.zip + ftp://ftp.sogang.ac.kr/pub/msdos/garbo_pc/editor/u-sedit2.zip + + U-SEDIT3.ZIP, by Mike Arst (24 Jan. 1992) + http://www.student.northpark.edu/pemente/sed/u-sedit3.zip + CompuServe DTPFORUM, "PC DTP Utilities" library, file SEDDOC.ZIP + + Another sed FAQ + http://www.dreamwvr.com/sed-info/sed-faq.html + + sed-tutorial, by Felix von Leitner + http://www.math.fu-berlin.de/~leitner/sed/tutorial.html + + "Manipulating text with sed," chapter 14 of the SCO OpenServer + "Operating System Users Guide" + http://ou800doc.caldera.com/SHL_automate/CTOC-Manipulating_text_with_sed.html + + "Combining the Bourne-shell, sed and awk in the UNIX environment + for language analysis," by Lothar Schmitt and Kiel Christianson. + This basic tutorial on the Bourne shell, sed and awk downloads as a + 71-page PostScript file (compressed to 290K with gzip). You may + need to navigate down from the root to get the file. + ftp://ftp.u-aizu.ac.jp/u-aizu/doc/Tech-Report/1997/97-2-007.tar.gz + available upon request from Lothar Schmitt + +2.3.4. General web and ftp sites + + http://sed.sourceforge.net/grabbag # Collected scripts + http://main.rtfiber.com.tw/~changyj/sed/ # Yao-Jen Chang + http://www.math.fu-berlin.de/~guckes/sed/ # Sven Guckes + http://www.math.fu-berlin.de/~leitner/sed/ # Felix von Leitner + http://www.dbnet.ece.ntua.gr/~george/sed/ # Yiorgos Adamopoulos + http://www.student.northpark.edu/pemente/sed/ # Eric Pement + + http://spacsun.rice.edu/FAQ/sed.html + ftp://algos.inesc.pt/pub/users/cdua/scripts.tar.gz (sed and shell scripts) + + "Handy One-Liners For Sed", compiled by Eric Pement. A large list + of 1-line sed commands which can be executed from the command line. + http://sed.sourceforge.net/sed1line.txt + http://www.student.northpark.edu/pemente/sed/sed1line.txt + + "Handy One-Liners For Sed", translated to Portuguese + http://wmaker.lrv.ufsc.br/sed_ptBR.html + + The Single UNIX Specification, Version 3 (technical man page) + http://www.opengroup.org/onlinepubs/007904975/utilities/sed.html + + Getting started with sed + http://www.cs.hmc.edu/tech_docs/qref/sed.html + + masm to gas converter + http://www.delorie.com/djgpp/faq/converting/asm2s-sed.html + + mail2html.zip + http://www.crispen.org/src/#mail2html + + sample uses of sed in batch files and scripts (Benny Pederson) + http://users.cybercity.dk/~bse26236/batutil/help/SED.HTM + + dc.sed - the most complex and impressive sed script ever written. + This sed script by Greg Ubben emulates the Unix dc (desk + calculator), including base conversion, exponentiation, square + roots, and much more. + http://sed.sourceforge.net/grabbag/scripts/dc_overview.htm + + If you should find other tutorials or scripts that should be added + to this document, please forward the URLs to the FAQ maintainer. + +------------------------------ + +3. TECHNICAL + +3.1. More detailed explanation of basic sed + + Sed takes a script of editing commands and applies each command, in + order, to each line of input. After all the commands have been + applied to the first line of input, that line is output. A second + input line is taken for processing, and the cycle repeats. Sed + scripts can address a single line by line number or by matching a + /RE pattern/ on the line. An exclamation mark '!' after a regex + ('/RE/!') or line number will select all lines that do NOT match + that address. Sed can also address a range of lines in the same + manner, using a comma to separate the 2 addresses. + + $d # delete the last line of the file + /[0-9]\{3\}/p # print lines with 3 consecutive digits + 5!s/ham/cheese/ # except on line 5, replace 'ham' with 'cheese' + /awk/!s/aaa/bb/ # unless 'awk' is found, replace 'aaa' with 'bb' + 17,/foo/d # delete all lines from line 17 up to 'foo' + + Following an address or address range, sed accepts curly braces + '{...}' so several commands may be applied to that line or to the + lines matched by the address range. On the command line, semicolons + ';' separate each instruction and must precede the closing brace. + + sed '/Owner:/{s/yours/mine/g;s/your/my/g;s/you/me/g;}' file + + Range addresses operate differently depending on which version of + sed is used (see section 3.4, below). For further information on + using sed, consult the references in section 2.3, above. + +3.1.1. Regular expressions on the left side of "s///" + + All versions of sed support Basic Regular Expressions (BREs). For + the syntax of BREs, enter "man ed" at a Unix shell prompt. A + technical description of BREs from IEEE POSIX 1003.1-2001 and the + Single UNIX Specification Version 3 is available online at: + http://www.opengroup.org/onlinepubs/007904975/basedefs/xbd_chap09.html#tag_09_03 + + Sed normally supports BREs plus '\n' to match a newline in the + pattern space, plus '\xREx' as equivalent to '/RE/', where 'x' is any + character other than a newline or another backslash. + + Some versions of sed support supersets of BREs, or "extended + regular expressions", which offer additional metacharacters for + increased flexibility. For additional information on extended REs + in GNU sed, see sections 3.7 ("GNU/POSIX extensions to regular + expressions") and 6.7.3 ("Special syntax in REs"), below. + + Though not required by BREs, some versions of sed support \t to + represent a TAB, \r for carriage return, \xHH for direct entry of + hex codes, and so forth. Other versions of sed do not. + + ssed (super-sed) introduced many new features for LHS pattern + matching, too many to give here. The complete list is found in + section 6.7.3.H ("ssed"), below. + +3.1.2. Escape characters on the right side of "s///" + + The right-hand side (the replacement part) in "s/find/replace/" is + almost always a string literal, with no interpolation of these + metacharacters: + + . ^ $ [ ] { } ( ) ? + * | + + Three things *are* interpolated: ampersand (&), backreferences, and + options for special seds. An ampersand on the RHS is replaced by + the entire expression matched on the LHS. There is _never_ any + reason to use grouping like this: + + s/\(some-complex-regex\)/one two \1 three/ + + since you can do this instead: + + s/some-complex-regex/one two & three/ + + To enter a literal ampersand on the RHS, type '\&'. + + Grouping and backreferences: All versions of sed support grouping + and backreferences on the LHS and backreferences only on the RHS. + Grouping allows a series of characters to be collected in a set, + indicating the boundaries of the set with \( and \). Then the set + can be designated to be repeated a certain number of times + + \(like this\)* or \(like this\)\{5,7\}. + + Groups can also be nested "\(like \(this\) is here\)" and may + contain any valid RE. Backreferences repeat the contents of a + particular group, using a backslash and a digit (1-9) for each + corresponding group. In other words, "/\(pom\)\1/" is another way + of writing "/pompom/". If groups are nested, backreference numbers + are counted by matching \( in strict left to right order. Thus, + /..\(the \(word\)\) \("foo"\)../ is matched by the backreference + \3. Backreferences can be used in the LHS, the RHS, and in normal + RE addressing (see section 3.3). Thus, + + /\(.\)\1\(.\)\2\(.\)\3/; # matches "bookkeeper" + /^\(.\)\(.\)\(.\)\3\2\1$/; # finds 6-letter palindromes + + Seds differ in how they treat invalid backreferences where no + corresponding group occurs. To insert a literal ampersand or + backslash into the RHS, prefix it with a backslash: \& or \\. + + ssed, sed16, and sedmod permit additional options on the RHS. They + all support changing part of the replacement string to upper case + (\u or \U), lower case (\l or \L), or to end case conversion (\E). + Both sed16 and sedmod support awk-style word references ($1, $2, + $3, ...) and $0 to insert the entire line before conversion. + + echo ab ghi | sed16 "s/.*/$0 - \U$2/" # prints "ab ghi - GHI" + + *Note:* This feature of sed16 and sedmod will break sed scripts which + put a dollar sign and digit into the RHS. Though this is an unlikely + combination, it's worth remembering if you use other people's scripts. + +3.1.3. Substitution switches + + Standard versions of sed support 4 main flags or switches which may + be added to the end of an "s///" command. They are: + + N - Replace the Nth match of the pattern on the LHS, where + N is an integer between 1 and 512. If N is omitted, + the default is to replace the first match only. + g - Global replace of all matches to the pattern. + p - Print the results to stdout, even if -n switch is used. + w file - Write the pattern space to 'file' if a replacement was + done. If the file already exists when the script is + executed, it is overwritten. During script execution, + w appends to the file for each match. + + GNU sed 3.02 and ssed also offer the /I switch for doing a + case-insensitive match. For example, + + echo ONE TWO | gsed "s/one/unos/I" # prints "unos TWO" + + GNU sed 4.x and ssed add the /M switch, to simplify working with + multi-line patterns: when it is used, ^ or $ will match BOL or EOL. + \` and \' remain available to match the start and end of pattern + space, respectively. + + ssed supports two more switches, /S and /X, when its Perl mode is + used. They are described in detail in section 6.7.3.H, below. + +3.1.4. Command-line switches + + All versions of sed support two switches, -e and -n. Though sed + usually separates multiple commands with semicolons (e.g., "H;d;"), + certain commands could not accept a semicolon command separator. + These include :labels, 't', and 'b'. These commands had to occur + last in a script, separated by -e option switches. For example: + + # The 'ta' means jump to label :a if last s/// returns true + sed -e :a -e '$!N;s/\n=/ /;ta' -e 'P;D' file + + The -n switch turns off sed's default behavior of printing every + line. With -n, lines are printed only if explicitly told to. In + addition, for certain versions of sed, if an external script begins + with "#n" as its first two characters, the output is suppressed + (exactly as if -n had been entered on the command line). A list of + which versions appears in section 6.7.2., below. + + GNU sed 4.x and ssed support additional switches. -l (lowercase L), + followed by a number, lets you adjust the default length of the 'l' + and 'L' commands (note that these implementations of sed also + support an argument to these commands, to tailor the length + separately of each occurrence of the command). + + -i activates in-place editing (see section 4.41.1, below). -s + treats each file as a separate stream: sed by default joins all the + files, so $ represents the last line of the last file; 15 means the + 15th line in the joined stream; and /abc/,/def/ might match across + files. + + When -s is used, however all addresses refer to single files. For + example, $ represents the last line of each input file; 15 means + the 15th line of each input file; and /abc/,/def/ will be "reset" + (in other words, sed will not execute the commands and start + looking for /abc/ again) if a file ends before /def/ has been + matched. Note that -i automatically activates this interpretation + of addresses. + +3.2. Common one-line sed scripts + + A separate document of over 70 handy "one-line" sed commands is + available at + http://sed.sourceforge.net/sed1line.txt + + Here are several common sed commands for one-line use. MS-DOS users + should replace single quotes ('...') with double quotes ("...") in + these examples. A specific filename usually follows the script, + though the input may also come via piping or redirection. + + # Double space a file + sed G file + + # Triple space a file + sed 'G;G' file + + # Under UNIX: convert DOS newlines (CR/LF) to Unix format + sed 's/.$//' file # assumes that all lines end with CR/LF + sed 's/^M$// file # in bash/tcsh, press Ctrl-V then Ctrl-M + + # Under DOS: convert Unix newlines (LF) to DOS format + sed 's/$//' file # method 1 + sed -n p file # method 2 + + # Delete leading whitespace (spaces/tabs) from front of each line + # (this aligns all text flush left). '^t' represents a true tab + # character. Under bash or tcsh, press Ctrl-V then Ctrl-I. + sed 's/^[ ^t]*//' file + + # Delete trailing whitespace (spaces/tabs) from end of each line + sed 's/[ ^t]*$//' file # see note on '^t', above + + # Delete BOTH leading and trailing whitespace from each line + sed 's/^[ ^t]*//;s/[ ^]*$//' file # see note on '^t', above + + # Substitute "foo" with "bar" on each line + sed 's/foo/bar/' file # replaces only 1st instance in a line + sed 's/foo/bar/4' file # replaces only 4th instance in a line + sed 's/foo/bar/g' file # replaces ALL instances within a line + + # Substitute "foo" with "bar" ONLY for lines which contain "baz" + sed '/baz/s/foo/bar/g' file + + # Delete all CONSECUTIVE blank lines from file except the first. + # This method also deletes all blank lines from top and end of file. + # (emulates "cat -s") + sed '/./,/^$/!d' file # this allows 0 blanks at top, 1 at EOF + sed '/^$/N;/\n$/D' file # this allows 1 blank at top, 0 at EOF + + # Delete all leading blank lines at top of file (only). + sed '/./,$!d' file + + # Delete all trailing blank lines at end of file (only). + sed -e :a -e '/^\n*$/{$d;N;};/\n$/ba' file + + # If a line ends with a backslash, join the next line to it. + sed -e :a -e '/\\$/N; s/\\\n//; ta' file + + # 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 '$!N;s/\n=/ /;ta' -e 'P;D' file + +3.3. Addressing and address ranges + + Sed commands may have an optional "address" or "address range" + prefix. If there is no address or address range given, then the + command is applied to all the lines of the input file or text + stream. Three commands cannot take an address prefix: + + - labels, used to branch or jump within the script + - the close brace, '}', which ends the '{' "command" + - the '#' comment character, also technically a "command" + + An address can be a line number (such as 1, 5, 37, etc.), a regular + expression (written in the form /RE/ or \xREx where 'x' is any + character other than '\' and RE is the regular expression), or the + dollar sign ($), representing the last line of the file. An + exclamation mark (!) after an address or address range will apply + the command to every line EXCEPT the ones named by the address. A + null regex ("//") will be replaced by the last regex which was + used. Also, some seds do not support \xREx as regex delimiters. + + 5d # delete line 5 only + 5!d # delete every line except line 5 + /RE/s/LHS/RHS/g # substitute only if RE occurs on the line + /^$/b label # if the line is blank, branch to ':label' + /./!b label # ... another way to write the same command + \%.%!b label # ... yet another way to write this command + $!N # on all lines but the last, get the Next line + + Note that an embedded newline can be represented in an address by + the symbol \n, but this syntax is needed only if the script puts 2 + or more lines into the pattern space via the N, G, or other + commands. The \n symbol does *not* match the newline at an + end-of-line because when sed reads each line into the pattern space + for processing, it strips off the trailing newline, processes the + line, and adds a newline back when printing the line to standard + output. To match the end-of-line, use the '$' metacharacter, as + follows: + + /tape$/ # matches the word 'tape' at the end of a line + /tape$deck/ # matches the word 'tape$deck' with a literal '$' + /tape\ndeck/ # matches 'tape' and 'deck' with a newline between + + The following sed commands usually accept *only* a single address. + All other commands (except labels, '}', and '#') accept both single + addresses and address ranges. + + = print to stdout the line number of the current line + a after printing the current line, append "text" to stdout + i before printing the current line, insert "text" to stdout + q quit after the current line is matched + r file prints contents of "file" to stdout after line is matched + + Note that we said "usually." If you need to apply the '=', 'a', + 'i', or 'r' commands to each and every line within an address + range, this behavior can be coerced by the use of braces. Thus, + "1,9=" is an invalid command, but "1,9{=;}" will print each line + number followed by its line for the first 9 lines (and then print + the rest of the rest of the file normally). + + Address ranges occur in the form + + , or ,! + + where the address can be a line number or a standard /regex/. + can also be a dollar sign, indicating the end of file. + Under GNU sed 3.02+, ssed, and sed15+, may also be a + notation of the form +num, indicating the next _num_ lines after + is matched. + + Address ranges are: + + (1) Inclusive. The range "/From here/,/eternity/" matches all the + lines containing "From here" up to and including the line + containing "eternity". It will not stop on the line just prior to + "eternity". (If you don't like this, see section 4.24.) + + (2) Plenary. They always match full lines, not just parts of lines. + In other words, a command to change or delete an address range will + change or delete whole lines; it won't stop in the middle of a + line. + + (3) Multi-linear. Address ranges normally match 2 lines or more. + The second address will never match the same line the first address + did; therefore a valid address range always spans at least two + lines, with these exceptions which match only one line: + + - if the first address matches the last line of the file + - if using the syntax "/RE/,3" and /RE/ occurs only once in the + file at line 3 or below + - if using HHsed v1.5. See section 3.4. + + (4) Minimalist. In address ranges with /regex/ as , the + range "/foo/,/bar/" will stop at the first "bar" it finds, provided + that "bar" occurs on a line below "foo". If the word "bar" occurs + on several lines below the word "foo", the range will match all the + lines from the first "foo" up to the first "bar". It will not + continue hopping ahead to find more "bar"s. In other words, address + ranges are not "greedy," like regular expressions. + + (5) Repeating. An address range will try to match more than one + block of lines in a file. However, the blocks cannot nest. In + addition, a second match will not "take" the last line of the + previous block. For example, given the following text, + + start + stop start + stop + + the sed command '/start/,/stop/d' will only delete the first two + lines. It will not delete all 3 lines. + + (6) Relentless. If the address range finds a "start" match but + doesn't find a "stop", it will match every line from "start" to the + end of the file. Thus, beware of the following behaviors: + + /RE1/,/RE2/ # If /RE2/ is not found, matches from /RE1/ to the + # end-of-file. + + 20,/RE/ # If /RE/ is not found, matches from line 20 to the + # end-of-file. + + /RE/,30 # If /RE/ occurs any time after line 30, each + # occurrence will be matched in sed15+, sedmod, and + # GNU sed v3.02+. GNU sed v2.05 and 1.18 will match + # from the 2nd occurrence of /RE/ to the end-of-file. + + If these behaviors seem strange, remember that they occur because + sed does not look "ahead" in the file. Doing so would stop sed from + being a stream editor and have adverse effects on its efficiency. + If these behaviors are undesirable, they can be circumvented or + corrected by the use of nested testing within braces. The following + scripts work under GNU sed 3.02: + + # Execute your_commands on range "/RE1/,/RE2/", but if /RE2/ is + # not found, do nothing. + /RE1/{:a;N;/RE2/!ba;your_commands;} + + # Execute your_commands on range "20,/RE/", but if /RE/ is not + # found, do nothing. + 20{:a;N;/RE/!ba;your_commands;} + + As a side note, once we've used N to "slurp" lines together to test + for the ending expression, the pattern space will have gathered + many lines (possibly thousands) together and concatenated them as a + single expression, with the \n sequence marking line breaks. The + REs *within* the pattern space may have to be modified (e.g., you + must write '/\nStart/' instead of '/^Start/' and '/[^\n]*/' instead + of '/.*/') and other standard sed commands will be unavailable or + difficult to use. + + # Execute your_commands on range "/RE/,30", but if /RE/ occurs + # on line 31 or later, do not match it. + 1,30{/RE/,$ your_commands;} + + For related suggestions on using address ranges, see sections 4.2, + 4.15, and 4.19 of this FAQ. Also, note the following section. + +3.4. Address ranges in GNU sed and HHsed + + (1) GNU sed 3.02+, ssed, and sed15+ all support address ranges like: + + /regex/,+5 + + which match /regex/ plus the next 5 lines (or EOF, whichever comes + first). + + (2) GNU sed v3.02.80 (and above) and ssed support address ranges of: + + 0,/regex/ + + as a special case to permit matching /regex/ if it occurs on the + first line. This syntax permits a range expression that matches + every line from the top of the file to the first instance of + /regex/, even if /regex/ is on the first line. + + (3) HHsed (sed15) has an exceptional way of implementing + + /regex1/,/regex2/ + + If /RE1/ and /RE2/ both occur on the *same* line, HHsed will match + that single line. In other words, an address range block can + consist of just one line. HHsed will then look for the next + occurrence of /regex1/ to begin the block again. + + Every other version of sed (including sed16) requires 2 lines to + match an address range, and thus /regex1/ and /regex2/ cannot + successfully match just one line. See also the comments at + section 7.9.4, below. + + (4) BEGIN~STEP selection: ssed and GNU sed (v2.05 and above) offer + a form of addressing called "BEGIN~STEP selection". This is *not* a + range address, which selects an inclusive block of consecutive + lines from /start/ to /finish/. But I think it seems to belong here. + + Given an expression of the form "M~N", where M and N are integers, + GNU sed and ssed will select every Nth line, beginning at line M. + (With gsed v2.05, M had to be less than N, but this restriction is + no longer necessary). Both M and N may equal 0 ("0~0" selects every + line). These examples illustrate the syntax: + + sed '1~3d' file # delete every 3d line, starting with line 1 + # deletes lines 1, 4, 7, 10, 13, 16, ... + + sed '0~3d' file # deletes lines 3, 6, 9, 12, 15, 18, ... + + sed -n '2~5p' file # print every 5th line, starting with line 2 + # prints lines 2, 7, 12, 17, 22, 27, ... + + (5) Finally, GNU sed v2.05 has a bug in range addressing (see + section 7.5), which was fixed in the higher versions. + + +3.5. Debugging sed scripts + + The following two debuggers should make it easier to understand how + sed scripts operate. They can save hours of grief when trying to + determine the problems with a sed script. + + (1) sd (sed debugger), by Brian Hiles + + This debugger runs under a Unix shell, is powerful, and is easy to + use. sd has conditional breakpoints and spypoints of the pattern + space and hold space, on any scope defined by regex match and/or + script line number. It can be semi-automated, can save diagnostic + reports, and shows potential problems with a sed script before it + tries to execute it. The script is robust and requires the Unix + shell utilities plus the Bourne shell or Korn shell to execute. + + http://sed.sourceforge.net/grabbag/scripts/sd.ksh.txt (2003) + http://sed.sourceforge.net/grabbag/scripts/sd.sh.txt (1998) + + (2) sedsed, by Aurelio Jargas + + This debugger requires Python to run it, and it uses your own + version of sed, whatever that may be. It displays the current input + line, the pattern space, and the hold space, before and after each + sed command is executed. + + http://sedsed.sourceforge.net + + +3.6. Notes about s2p, the sed-to-perl translator + + s2p (sed to perl) is a Perl program to convert sed scripts into the + Perl programming language; it is included with many versions of + Perl. These problems have been found when using s2p: + + (1) Doesn't recognize the semicolon properly after s/// commands. + + s/foo/bar/g; + + (2) Doesn't trim trailing whitespace after s/// commands. Even lone + trailing spaces, without comments, produce an error. + + (3) Doesn't handle multiple commands within braces. E.g., + + 1,4{=;G;} + + will produce perl code with missing braces, and miss the second "G" + command as well. In fact, any commands after the first one are + missed in the perl output script, and the output perl script will + also contain mismatched braces. + +3.7. GNU/POSIX extensions to regular expressions + + GNU sed supports "character classes" in addition to regular + character sets, such as [0-9A-F]. Like regular character sets, + character classes represent any single character within a set. + + "Character classes are a new feature introduced in the POSIX + standard. A character class is a special notation for describing + lists of characters that have a specific attribute, but where the + actual characters themselves can vary from country to country + and/or from character set to character set. For example, the notion + of what is an alphabetic character differs in the USA and in + France." [quoted from the docs for GNU awk v3.1.0.] + + Though character classes don't generally conserve space on the + line, they help make scripts portable for international use. The + equivalent character sets _for U.S. users_ follows: + + [[:alnum:]] - [A-Za-z0-9] Alphanumeric characters + [[:alpha:]] - [A-Za-z] Alphabetic characters + [[:blank:]] - [ \x09] Space or tab characters only + [[:cntrl:]] - [\x00-\x19\x7F] Control characters + [[:digit:]] - [0-9] Numeric characters + [[:graph:]] - [!-~] Printable and visible characters + [[:lower:]] - [a-z] Lower-case alphabetic characters + [[:print:]] - [ -~] Printable (non-Control) characters + [[:punct:]] - [!-/:-@[-`{-~] Punctuation characters + [[:space:]] - [ \t\v\f] All whitespace chars + [[:upper:]] - [A-Z] Upper-case alphabetic characters + [[:xdigit:]] - [0-9a-fA-F] Hexadecimal digit characters + + Note that [[:graph:]] does not match the space " ", but [[:print:]] + does. Some character classes may (or may not) match characters in + the high ASCII range (ASCII 128-255 or 0x80-0xFF), depending on + which C library was used to compile sed. For non-English languages, + [[:alpha:]] and other classes may also match high ASCII characters. + +------------------------------ + +4. EXAMPLES + + ONE-CHARACTER QUESTIONS + +4.1. How do I insert a newline into the RHS of a substitution? + + Several versions of sed permit '\n' to be typed directly into the + RHS, which is then converted to a newline on output: ssed, + gsed302a+, gsed103 (with the -x switch), sed15+, sedmod, and + UnixDOS sed. The _easiest_ solution is to use one of these + versions. + + For other versions of sed, try one of the following: + + (a) If typing the sed script from a Bourne shell, use one backslash + "\" if the script uses 'single quotes' or two backslashes "\\" if + the script requires "double quotes". In the example below, note + that the leading '>' on the 2nd line is generated by the shell to + prompt the user for more input. The user types in slash, + single-quote, and then ENTER to terminate the command: + + [sh-prompt]$ echo twolines | sed 's/two/& new\ + >/' + two new + lines + [bash-prompt]$ + + (b) Use a script file with one backslash '\' in the script, + immediately followed by a newline. This will embed a newline into + the "replace" portion. Example: + + sed -f newline.sed files + + # newline.sed + s/twolines/two new\ + lines/g + + Some versions of sed may not need the trailing backslash. If so, + remove it. + + (c) Insert an unused character and pipe the output through tr: + + echo twolines | sed 's/two/& new=/' | tr "=" "\n" # produces + two new + lines + + (d) Use the "G" command: + + G appends a newline, plus the contents of the hold space to the end + of the pattern space. If the hold space is empty, a newline is + appended anyway. The newline is stored in the pattern space as "\n" + where it can be addressed by grouping "\(...\)" and moved in the + RHS. Thus, to change the "twolines" example used earlier, the + following script will work: + + sed '/twolines/{G;s/\(two\)\(lines\)\(\n\)/\1\3\2/;}' + + (e) Inserting full lines, not breaking lines up: + + If one is not *changing* lines but only inserting complete lines + before or after a pattern, the procedure is much easier. Use the + "i" (insert) or "a" (append) command, making the alterations by an + external script. To insert "This line is new" BEFORE each line + matching a regex: + + /RE/i This line is new # HHsed, sedmod, gsed 3.02a + /RE/{x;s/$/This line is new/;G;} # other seds + + The two examples above are intended as "one-line" commands entered + from the console. If using a sed script, "i\" immediately followed + by a literal newline will work on all versions of sed. Furthermore, + the command "s/$/This line is new/" will only work if the hold + space is already empty (which it is by default). + + To append "This line is new" AFTER each line matching a regex: + + /RE/a This line is new # HHsed, sedmod, gsed 3.02a + /RE/{G;s/$/This line is new/;} # other seds + + To append 2 blank lines after each line matching a regex: + + /RE/{G;G;} # assumes the hold space is empty + + To replace each line matching a regex with 5 blank lines: + + /RE/{s/.*//;G;G;G;G;} # assumes the hold space is empty + + (f) Use the "y///" command if possible: + + On some Unix versions of sed (not GNU sed!), though the s/// + command won't accept '\n' in the RHS, the y/// command does. If + your Unix sed supports it, a newline after "aaa" can be inserted + this way (which is not portable to GNU sed or other seds): + + s/aaa/&~/; y/~/\n/; # assuming no other '~' is on the line! + +4.2. How do I represent control-codes or nonprintable characters? + + Several versions of sed support the notation \xHH, where "HH" are + two hex digits, 00-FF: ssed, GNU sed v3.02.80 and above, GNU sed + v1.03, sed16 and sed15 (HHsed). Try to use one of those versions. + + Sed is not intended to process binary or object code, and files + which contain nulls (0x00) will usually generate errors in most + versions of sed. The latest versions of GNU sed and ssed are an + exception; they permit nulls in the input files and also in + regexes. + + On Unix platforms, the 'echo' command may allow insertion of octal + or hex values, e.g., `echo "\0nnn"` or `echo -n "\0nnn"`. The echo + command may also support syntax like '\\b' or '\\t' for backspace + or tab characters. Check the man pages to see what syntax your + version of echo supports. Some versions support the following: + + # replace 0x1A (32 octal) with ASCII letters + sed 's/'`echo "\032"`'/Ctrl-Z/g' + + # note the 3 backslashes in the command below + sed "s/.`echo \\\b`//g" + +4.3. How do I convert files with toggle characters, like +this+, to +look like [i]this[/i]? + + Input files, especially message-oriented text files, often contain + toggle characters for emphasis, like ~this~, *this*, or =this=. Sed + can make the same input pattern produce alternating output each + time it is encountered. Typical needs might be to generate HMTL + codes or print codes for boldface, italic, or underscore. This + script accomodates multiple occurrences of the toggle pattern on + the same line, as well as cases where the pattern starts on one + line and finishes several lines later, even at the end of the file: + + # sed script to convert +this+ to [i]this[/i] + :a + /+/{ x; # If "+" is found, switch hold and pattern space + /^ON/{ # If "ON" is in the (former) hold space, then .. + s///; # .. delete it + x; # .. switch hold space and pattern space back + s|+|[/i]|; # .. turn the next "+" into "[/i]" + ba; # .. jump back to label :a and start over + } + s/^/ON/; # Else, "ON" was not in the hold space; create it + x; # Switch hold space and pattern space + s|+|[i]|; # Turn the first "+" into "[i]" + ba; # Branch to label :a to find another pattern + } + #---end of script--- + + This script uses the hold space to create a "flag" to indicate + whether the toggle is ON or not. We have added remarks to + illustrate the script logic, but in most versions of sed remarks + are not permitted after 'b'ranch commands or labels. + + If you are sure that the +toggle+ characters never cross line + boundaries (i.e., never begin on one line and end on another), this + script can be reduced to one line: + + s|+\([^+][^+]*\)+|[i]\1[/i]|g + + If your toggle pattern contains regex metacharacters (such as '*' + or perhaps '+' or '?'), remember to quote them with backslashes. + + CHANGING STRINGS + +4.10. How do I perform a case-insensitive search? + + Several versions of sed support case-insensitive matching: ssed and + GNU sed v3.02+ (with I flag after s/// or /regex/); sedmod with the + -i switch; and sed16 (which supports both types of switches). + + With other versions of sed, case-insensitive searching is awkward, + so people may use awk or perl instead, since these programs have + options for case-insensitive searches. In gawk/mawk, use "BEGIN + {IGNORECASE=1}" and in perl, "/regex/i". For other seds, here are + three solutions: + + Solution 1: convert everything to upper case and search normally + + # sed script, solution 1 + h; # copy the original line to the hold space + # convert the pattern space to solid caps + y/abcdefghijklmnopqrstuvwxyz/ABCDEFGHIJKLMNOPQRSTUVWXYZ/ + # now we can search for the word "CARLOS" + /CARLOS/ { + # add or insert lines. Note: "s/.../.../" will not work + # here because we are searching a modified pattern + # space and are not printing the pattern space. + } + x; # get back the original pattern space + # the original pattern space will be printed + #---end of sed script--- + + Solution 2: search for both cases + + Often, proper names will either start with all lower-case ("unix"), + with an initial capital letter ("Unix") or occur in solid caps + ("UNIX"). There may be no need to search for every possibility. + + /UNIX/b match + /[Uu]nix/b match + + Solution 3: search for all possible cases + + # If you must, search for any possible combination + /[Ca][Aa][Rr][Ll][Oo][Ss]/ { ... } + + Bear in mind that as the pattern length increases, this solution + becomes an order of magnitude slower than the one of Solution 1, at + least with some implementations of sed. + +4.11. How do I match only the first occurrence of a pattern? + + (1) The general solution is to use GNU sed or ssed, with one of + these range expressions. The first script ("print only the first + match") works with any version of sed: + + sed -n '/RE/{p;q;}' file # print only the first match + sed '0,/RE/{//d;}' file # delete only the first match + sed '0,/RE/s//to_that/' file # change only the first match + + (2) If you cannot use GNU sed and if you *know* the pattern will + not occur on the first line, this will work: + + sed '1,/RE/{//d;}' file # delete only the first match + sed '1,/RE/s//to_that/' file # change only the first match + + (3) If you cannot use GNU sed and the pattern *might* occur on the + first line, use one of the following commands (credit for short GNU + script goes to Donald Bruce Stewart): + + sed '/RE/{x;/Y/!{s/^/Y/;h;d;};x;}' file # delete (one way) + sed -e '/RE/{d;:a' -e '$!N;$ba' -e '}' file # delete (another way) + sed '/RE/{d;:a;N;$ba;}' file # same script, GNU sed + sed -e '/RE/{s//to_that/;:a' -e '$!N;$!ba' -e '}' file # change + + Still another solution, using a flag in the hold space. This is + portable to all seds and works if the pattern is on the first line: + + # sed script to change "foo" to "bar" only on the first occurrence + 1{x;s/^/first/;x;} + 1,/foo/{x;/first/s///;x;s/foo/bar/;} + #---end of script--- + +4.12. How do I parse a comma-delimited (CSV) data file? + + Comma-delimited data files can come in several forms, requiring + increasing levels of complexity in parsing and handling. They are + often referred to as CSV files (for "comma separated values") and + occasionally as SDF files (for "standard data format"). Note that + some vendors use "SDF" to refer to variable-length records with + comma-separated fields which are "double-quoted" if they contain + character values, while other vendors use "SDF" to designate + fixed-length records with fixed-length, nonquoted fields! (For help + with fixed-length fields, see question 4.23) + + The term "CSV" became a de-facto standard when Microsoft Excel used + it as an optional output file format. + + Here are 4 different forms you may encounter in comma-delimited data: + + (a) No quotes, no internal commas + + 1001,John Smith,PO Box 123,Chicago,IL,60699 + 1002,Mary Jones,320 Main,Denver,CO,84100, + + (b) Like (a), with quotes around each field + + "1003","John Smith","PO Box 123","Chicago","IL","60699" + "1004","Mary Jones","320 Main","Denver","CO","84100" + + (c) Like (b), with embedded commas + + "1005","Tom Hall, Jr.","61 Ash Ct.","Niles","OH","44446" + "1006","Bob Davis","429 Pine, Apt. 5","Boston","MA","02128" + + (d) Like (c), with embedded commas and quotes + + "1007","Sue "Red" Smith","19 Main","Troy","MI","48055" + "1008","Joe "Hey, guy!" Hall","POB 44","Reno","NV","89504" + + In each example above, we have 7 fields and 6 commas which function + as field separators. Case (c) is a very typical form of these data + files, with double quotes used to enclose each field and to protect + internal commas (such as "Tom Hall, Jr.") from interpretation as + field separators. However, many times the data may include both + embedded quotation marks as well as embedded commas, as seen by + case (d), above. + + Case (d) is the closest to Microsoft CSV format. *However*, the + Microsoft CSV format allows embedded newlines within a + double-quoted field. If embedded newlines within fields are a + possibility for your data, you should consider using something + other than sed to work with the data file. + + Before handling a comma-delimited data file, make sure that you + fully understand its format and check the integrity of the data. + Does each line contain the same number of fields? Should certain + fields be composed only of numbers or of two-letter state + abbreviations in all caps? Sed (or awk or perl) should be used to + validate the integrity of the data file before you attempt to alter + it or extract particular fields from the file. + + After ensuring that each line has a valid number of fields, use sed + to locate and modify individual fields, using the \(...\) grouping + command where needed. + + In case (a): + + sed 's/^[^,]*,[^,]*,[^,]*,[^,]*,/.../' + ^ ^ ^ + | | |_ 3rd field + | |_______ 2nd field + |_____________ 1st field + + # Unix script to delete the second field for case (a) + sed 's/^\([^,]*\),[^,]*,/\1,,/' file + + # Unix script to change field 1 to 9999 for case (a) + sed 's/^[^,]*,/9999,/' file + + In cases (b) and (c): + + sed 's/^"[^"]*","[^"]*","[^"]*","[^"]*",/.../' + 1st-- 2nd-- 3rd-- 4th-- + + # Unix script to delete the second field for case (c) + sed 's/^\("[^"]*"\),"[^"]*",/\1,"",/' file + + # Unix script to change field 1 to 9999 for case (c) + sed 's/^"[^"]*",/"9999",/' file + + + In case (d): + + One way to parse such files is to replace the 3-character field + separator "," with an unused character like the tab or vertical + bar. (Technically, the field separator is only the comma while the + fields are surrounded by "double quotes", but the net _effect_ is + that fields are separated by quote-comma-quote, with quote + characters added to the beginning and end of each record.) Search + your datafile _first_ to make sure that your character appears + nowhere in it! + + sed -n '/|/p' file # search for any instance of '|' + # if it's not found, we can use the '|' to separate fields + + Then replace the 3-character field separator and parse as before: + + # sed script to delete the second field for case (d) + s/","/|/g; # global change of "," to bar + s/^\([^|]*\)|[^|]|/\1||/; # delete 2nd field + s/|/","/g; # global change of bar back to "," + #---end of script--- + + # sed script to change field 1 to 9999 for case (d) + # Remember to accommodate leading and trailing quote marks + s/","/|/g; + s/^[^|]*|/"9999|/; + s/|/","/g; + #---end of script--- + + Note that this technique works only if _each_ and _every_ field is + surrounded with double quotes, including empty fields. + + The following solution is for more complex examples of (d), such + as: not all fields contain "double-quote" marks, or the presence of + embedded "double-quote" marks within fields, or extraneous + whitespace around field delimiters. (Thanks to Greg Ubben for this + script!) + + # sed script to convert case (d) to bar-delimited records + s/^ *\(.*[^ ]\) *$/|\1|/; + s/" *, */"|/g; + : loop + s/| *\([^",|][^,|]*\) *, */|\1|/g; + s/| *, */|\1|/g; + t loop + s/ *|/|/g; + s/| */|/g; + s/^|\(.*\)|$/\1/; + #---end of script--- + + For example, it turns this (which is badly-formed but legal): + + first,"",unquoted ,""this" is, quoted " ,, sub "quote" inside, f", lone " empty: + + into this: + + first|""|unquoted|""this" is, quoted "||sub "quote" inside|f"|lone " empty: + + Note that the script preserves the "double-quote" marks, but + changes only the commas where they are used as field separators. I + have used the vertical bar "|" because it's easier to read, but you + may change this to another field separator if you wish. + + If your CSV datafile is more complex, it would probably not be + worth the effort to write it in sed. For such a case, you should + use Perl with a dedicated CSV module (there are at least two recent + CSV parsers available from CPAN). + +4.13. How do I handle fixed-length, columnar data? + + Sed handles fixed-length fields via \(grouping\) and backreferences + (\1, \2, \3 ...). If we have 3 fields of 10, 25, and 9 characters + per field, our sed script might look like so: + + s/^\(.\{10\}\)\(.\{25\}\)\(.\{9\}\)/\3\2\1/; # Change the fields + ^^^^^^^^^^^~~~~~~~~~~~========== # from 1,2,3 to 3,2,1 + field #1 field #2 field #3 + + This is a bit hard to read. By using GNU sed or ssed with the -r + switch active, it can look like this: + + s/^(.{10})(.{25})(.{9})/\3\2\1/; # Using the -r switch + + To delete a field in sed, use grouping and omit the backreference + from the field to be deleted. If the data is long or difficult to + work with, use ssed with the -R switch and the /x flag after an s/// + command, to insert comments and remarks about the fields. + + For records with many fields, use GNU awk with the FIELDWIDTHS + variable set in the top of the script. For example: + + awk 'BEGIN{FIELDWIDTHS = "10 25 9"}; {print $3 $2 $1}' file + + This is much easier to read than a similar sed script, especially + if there are more than 5 or 6 fields to manipulate. + +4.14. How do I commify a string of numbers? + + Use the simplest script necessary to accomplish your task. As + variations of the line increase, the sed script must become more + complex to handle additional conditions. Whole numbers are + simplest, followed by decimal formats, followed by embedded words. + + Case 1: simple strings of whole numbers separated by spaces or + commas, with an optional negative sign. To convert this: + + 4381, -1222333, and 70000: - 44555666 1234567890 words + 56890 -234567, and 89222 -999777 345888777666 chars + + to this: + + 4,381, -1,222,333, and 70,000: - 44,555,666 1,234,567,890 words + 56,890 -234,567, and 89,222 -999,777 345,888,777,666 chars + + use one of these one-liners: + + sed ':a;s/\B[0-9]\{3\}\>/,&/;ta' # GNU sed + sed -e :a -e 's/\(.*[0-9]\)\([0-9]\{3\}\)/\1,\2/;ta' # other seds + + Case 2: strings of numbers which may have an embedded decimal + point, separated by spaces or commas, with an optional negative + sign. To change this: + + 4381, -6555.1212 and 70000, 7.18281828 44906982.071902 + 56890 -2345.7778 and 8.0000: -49000000 -1234567.89012 + + to this: + + 4,381, -6,555.1212 and 70,000, 7.18281828 44,906,982.071902 + 56,890 -2,345.7778 and 8.0000: -49,000,000 -1,234,567.89012 + + use the following command for GNU sed: + + sed ':a;s/\(^\|[^0-9.]\)\([0-9]\+\)\([0-9]\{3\}\)/\1\2,\3/g;ta' + + and for other versions of sed: + + sed -f case2.sed files + + # case2.sed + s/^/ /; # add space to start of line + :a + s/\( [-0-9]\{1,\}\)\([0-9]\{3\}\)/\1,\2/g + ta + s/ //; # remove space from start of line + #---end of script--- + +4.15. How do I prevent regex expansion on substitutions? + + Sometimes you want to *match* regular expression metacharacters as + literals (e.g., you want to match "[0-9]" or "\n"), to be replaced + with something else. The ordinary way to prevent expanding + metacharacters is to prefix them with a backslash. Thus, if "\n" + matches a newline, "\\n" will match the two-character string of + 'backslash' followed by 'n'. + + But doing this repeatedly can become tedious if there are many + regexes. The following script will replace alternating strings of + literals, where no character is interpreted as a regex + metacharacter: + + # filename: sub_quote.sed + # author: Paolo Bonzini + # sed script to add backslash to find/replace metacharacters + N; # add even numbered line to pattern space + s,[]/\\$*[],\\&,g; # quote all of [, ], /, \, $, or * + s,^,s/,; # prepend "s/" to front of pattern space + s,$,/,; # append "/" to end of pattern space + s,\n,/,; # change "\n" to "/", making s/from/to/ + #---end of script--- + + Here's a sample of how sub_quote.sed might be used. This example + converts typical sed regexes to perl-style regexes. The input file + consists of 10 lines: + + [0-9] + \d + [^0-9] + \D + \+ + + + \? + ? + \| + | + + Run the command "sed -f sub_quote.sed input", to transform the + input file (above) to 5 lines of output: + + s/\[0-9\]/\\d/ + s/\[^0-9\]/\\D/ + s/\\+/+/ + s/\\?/?/ + s/\\|/|/ + + The above file is itself a sed script, which can then be used to + modify other files. + +4.16. How do I convert a string to all lowercase or capital letters? + + The easiest method is to use a new version of GNU sed, ssed, sedmod + or sed16 and employ the \U, \L, or other switches on the right side + of an s/// command. For example, to convert any word which begins + with "reg" or "exp" into solid capital letters: + + sed -r "s/\<(reg|exp)[a-z]+/\U&/g" # gsed4.+ or ssed + sed "s/\ as word boundary markers in GNU sed. + /from/,/until/ { s/\/magenta/g; s/\/cyan/g; } + + # replace only from the words "ENDNOTES:" to the end of file + /ENDNOTES:/,$ { s/Schaff/Herzog/g; s/Kraft/Ebbing/g; } + + For technical details on using address ranges, see section 3.3 + ("Addressing and Address ranges"). + +4.21. How do I delete or change a block of text if the block contains + a certain regular expression? + + The following deletes the block between 'start' and 'end' + inclusively, if and only if the block contains the string + 'regex'. Written by Russell Davies, with additional comments: + + # sed script to delete a block if /regex/ matches inside it + :t + /start/,/end/ { # For each line between these block markers.. + /end/!{ # If we are not at the /end/ marker + $!{ # nor the last line of the file, + N; # add the Next line to the pattern space + bt + } # and branch (loop back) to the :t label. + } # This line matches the /end/ marker. + /regex/d; # If /regex/ matches, delete the block. + } # Otherwise, the block will be printed. + #---end of script--- + + Note: When the script above reaches /regex/, the entire multi-line + block is in the pattern space. To replace items inside the block, + use "s///". To change the entire block, use the 'c' (change) + command: + + /regex/c\ + 1: This will replace the entire block\ + 2: with these two lines of text. + +4.22. How do I locate a paragraph of text if the paragraph contains a + certain regular expression? + + Assume that paragraphs are separated by blank lines. For regexes + that are single terms, use one of the following scripts: + + sed -e '/./{H;$!d;}' -e 'x;/regex/!d' # most seds + sed '/./{H;$!d;};x;/regex/!d' # GNU sed + + To print paragraphs only if they contain 3 specific regular + expressions (RE1, RE2, and RE3), in any order in the paragraph: + + sed -e '/./{H;$!d;}' -e 'x;/RE1/!d;/RE2/!d;/RE3/!d' + + With this solution and the preceding one, if the paragraphs are + excessively long (more than 4k in length), you may overflow sed's + internal buffers. If using HHsed, you must add a "G;" command + immediately after the "x;" in the scripts above to defeat a bug + in HHsed (see section 7.9(5), below, for a description). + +4.23. How do I match a block of _specific_ consecutive lines? + + There are three ways to approach this problem: + + (1) Try to use a "/range/, /expression/" + (2) Try to use a "/multi-line\nexpression/" + (3) Try to use a block of "literal strings" + + We describe each approach in the following sections. + +4.23.1. Try to use a "/range/, /expression/" + + If the block of lines are strings that *never change their order* + and if the top line never occurs outside the block, like this: + + Abel + Baker + Charlie + Delta + + then these solutions will work for deleting the block: + + sed 's/^Abel$/{N;N;N;d;}' files # for blocks with few lines + sed '/^Abel$/, /^Zebra$/d' files # for blocks with many lines + sed '/^Abel$/,+25d' files # HHsed, sedmod, ssed, gsed 3.02.80 + + To change the block, use the 'c' (change) command instead of 'd'. + To print that block only, use the -n switch and 'p' (print) instead + of 'd'. To change some things inside the block, try this: + + /^Abel$/,/^Delta$/ { + :ack + N; + /\nDelta$/! b ack + # At this point, all the lines in the block are collected + s/ubstitute /somethin/g; + } + +4.23.2. Try to use a "multi-line\nexpression" + + If the top line of the block sometimes appears alone or is + sometimes followed by other lines, or if a partial block may occur + somewhere in the file, a multi-line expression may be required. + + In these examples, we give solutions for matching an N-line block. + The expression "/^RE1\nRE2\nRE3...$/" represents a properly formed + regular expression where \n indicates a newline between lines. Note + that the 'N' followed by the 'P;D;' commands forms a "sliding + window" technique. A window of N lines is formed. If the multi-line + pattern matches, the block is handled. If not, the top line is + printed and then deleted from the pattern space, and we try to + match at the next line. + + # sed script to delete 2 consecutive lines: /^RE1\nRE2$/ + $b + /^RE1$/ { + $!N + /^RE1\nRE2$/d + P;D + } + #---end of script--- + + # sed script to delete 3 consecutive lines. (This script + # fails under GNU sed v2.05 and earlier because of the 't' + # bug when s///n is used; see section 7.5(1) of the FAQ.) + : more + $!N + s/\n/&/2; + t enough + $!b more + : enough + /^RE1\nRE2\nRE3$/d + P;D + #---end of script--- + + For example, to delete a block of 5 consecutive lines, the previous + script must be altered in only two places: + + (1) Change the 2 in "s/\n/&/2;" to a 4 (the trailing semicolon is + needed to work around a bug in HHsed v1.5). + + (2) Change the regex line to "/^RE1\nRE2\nRE3\nRE4\nRE5$/d", + modifying the expression as needed. + + Suppose we want to delete a block of two blank lines followed by + the word "foo" followed by another blank line (4 lines in all). + Other blank lines and other instances of "foo" should be left + alone. After changing the '2' to a '3' (always one number less than + the total number of lines), the regex line would look like this: + "/^\n\nfoo\n$/d". (Thanks to Greg Ubben for this script.) + + As an alternative to work around the 't' bug in older versions of + GNU sed, the following script will delete 4 consecutive lines: + + # sed script to delete 4 consecutive lines. Use this if you + # require GNU sed 2.05 and below. + /^RE1$/!b + $!N + $!N + :a + $b + N + /^RE1\nRE2\nRE3\nRE4$/d + P + s/^.*\n\(.*\n.*\n.*\)$/\1/ + ba + #---end of script--- + + Its drawback is that it must be modified in 3 places instead of 2 + to adapt it for more lines, and as additional lines are added, the + 's' command is forced to work harder to match the regexes. On the + other hand, it avoids a bug with gsed-2.05 and illustrates another + way to solve the problem of deleting consecutive lines. + +4.23.3. Try to use a block of "literal strings" + + If you need to match a static block of text (which may occur any + number of times throughout a file), where the contents of the block + are known in advance, then this script is easy to use. It requires + an intermediate file, which we will call "findrep.txt" (below): + + A block of several consecutive lines to + be matched literally should be placed on + top. Regular expressions like .* or [a-z] + will lose their special meaning and be + interpreted literally in this block. + ---- + Four hyphens separate the two sections. Put + the replacement text in the lower section. + As above, sed symbols like &, \n, or \1 will + lose their special meaning. + + This is a 3-step process. A generic script called "blockrep.sed" + will read "findrep.txt" (above) and generate a custom script, which + is then used on the actual input file. In other words, + "findrep.txt" is a simplified description of the editing that you + want to do on the block, and "blockrep.sed" turns it into actual + sed commands. + + Use this process from a Unix shell or from a DOS prompt: + + sed -nf blockrep.sed findrep.txt >custom.sed + sed -f custom.sed input.file >output.file + erase custom.sed + + The generic script "blockrep.sed" follows below. It's fairly long. + Examining its output might help you understanding how to use the + _sliding window_ technique. + + # filename: blockrep.sed + # author: Paolo Bonzini + # Requires: + # (1) blocks to find and replace, e.g., findrep.txt + # (2) an input file to be changed, input.file + # + # blockrep.sed creates a second sed script, custom.sed, + # to find the lines above the row of 4 hyphens, globally + # replacing them with the lower block of text. GNU sed + # is recommended but not required for this script. + # + # Loop on the first part, accumulating the `from' text + # into the hold space. + :a + /^----$/! { + # Escape slashes, backslashes, the final newline and + # regular expression metacharacters. + s,[/\[.*],\\&,g + s/$/\\/ + H + # + # Append N cmds needed to maintain the sliding window. + x + 1 s,^.,s/, + 1! s/^/N\ + / + x + n + ba + } + # + # Change the final backslash to a slash to separate the + # two sides of the s command. + x + s,\\$,/, + x + # + # Until EOF, gather the substitution into hold space. + :b + n + s,[/\],\\&,g + $! s/$/\\/ + H + $! bb + # + # Start the RHS of the s command without a leading + # newline, add the P/D pair for the sliding window, and + # print the script. + g + s,/\n,/, + s,$,/\ + P\ + D,p + #---end of script--- + +4.24. How do I address all the lines between RE1 and RE2, excluding the + lines themselves? + + Normally, to address the lines between two regular expressions, RE1 + and RE2, one would do this: '/RE1/,/RE2/{commands;}'. Excluding + those lines takes an extra step. To put 2 arrows before each line + between RE1 and RE2, except for those lines: + + sed '1,/RE1/!{ /RE2/,/RE1/!s/^/>>/; }' input.fil + + The preceding script, though short, may be difficult to follow. It + also requires that /RE1/ cannot occur on the first line of the + input file. The following script, though it's not a one-liner, is + easier to read and it permits /RE1/ to appear on the first line: + + # sed script to replace all lines between /RE1/ and /RE2/, + # without matching /RE1/ or /RE2/ + /RE1/,/RE2/{ + /RE1/b + /RE2/b + s/^/>>/ + } + #---end of script--- + + Contents of input.fil: Output of sed script: + aaa aaa + bbb bbb + RE1 RE1 + aaa >>aaa + bbb >>bbb + ccc >>ccc + RE2 RE2 + end end + +4.25. How do I join two lines if line #1 ends in a [certain string]? + + This question appears in the section on one-line sed scripts, but + it comes up so many times that it needs a place here also. Suppose + a line ends with a particular string (often, a line ends with a + backslash). How do you bring up the second line after it, even in + cases where several consecutive lines all end in a backslash? + + sed -e :a -e '/\\$/N; s/\\\n//; ta' file # all seds + sed ':a; /\\$/N; s/\\\n//; ta' file # GNU sed, ssed, HHsed + + Note that this replaces the backslash-newline with nothing. You may + want to replace the backslash-newline with a single space instead. + +4.26. How do I join two lines if line #2 begins in a [certain string]? + + The inverse situation is another FAQ. Suppose a line begins with a + particular string. How do you bring that line up to follow the + previous line? In this example, we want to match the string "<<=" + at the beginning of one line, bring that line up to the end of the + line before it, and replace the string with a single space: + + sed -e :a -e '$!N;s/\n<<=/ /;ta' -e 'P;D' file # all seds + sed ':a; $!N;s/\n<<=/ /;ta;P;D' file # GNU, ssed, sed15+ + +4.27. How do I change all paragraphs to long lines? + + A frequent request is how to convert DOS-style textfiles, in which + each line ends with "paragraph marker", to Microsoft-style + textfiles, in which the "paragraph" marker only appears at the end + of real paragraphs. Sometimes this question is framed as, "How do I + remove the hard returns at the end of each line in a paragraph?" + + The problem occurs because newer word processors don't work the + same way older text editors did. Older text editors used a newline + (CR/LF in DOS; LF alone in Unix) to end each line on screen or on + disk, and used two newlines to separate paragraphs. Certain word + processors wanted to make paragraph reformatting and reflowing work + easily, so they use one newline to end a paragraph and never allow + newlines _within_ a paragraph. This means that textfiles created + with standard editors (Emacs, vi, Vedit, Boxer, etc.) appear to + have "hard returns" at inappropriate places. The following sed + script finds blocks of consecutive nonblank lines (i.e., paragraphs + of text), and converts each block into one long line with one "hard + return" at the end. + + # sed script to change all paragraphs to long lines + /./{H; $!d;} # Put each paragraph into hold space + x; # Swap hold space and pattern space + s/^\(\n\)\(..*\)$/\2\1/; # Move leading \n to end of PatSpace + s/\n\(.\)/ \1/g; # Replace all other \n with 1 space + # Uncomment the following line to remove excess blank lines: + # /./!d; + #---end of sed script--- + + If the input files have formatting or indentation that conveys + special meaning (like program source code), this script will remove + it. But if the text still needs to be extended, try 'par' + (paragraph reformatter) or the 'fmt' utility with the -t or -c + switches and the width option (-w) set to a number like 9999. + + SHELL AND ENVIRONMENT + +4.30. How do I read environment variables with sed? + +4.30.1. - on Unix platforms + + In Unix, environment variables begin with a dollar sign, such as + $TERM, $PATH, $var or $i. In sed, the dollar sign is used to + indicate the last line of the input file, the end of a line (in the + LHS), or a literal symbol (in the RHS). Sed cannot access variables + directly, so one must pay attention to shell quoting requirements + to expand the variables properly. + + To ALLOW the Unix shell to interpret the dollar sign, put the + script in double quotes: + + sed "s/_terminal-type_/$TERM/g" input.file >output.file + + To PREVENT the Unix shell from interpreting the dollar sign as a + shell variable, put the script in single quotes: + + sed 's/.$//' infile >outfile + + To use BOTH Unix $environment_vars and sed /end-of-line$/ pattern + matching, there are two solutions. (1) The easiest is to enclose + the script in "double quotes" so the shell can see the $variables, + and to prefix the sed metacharacter ($) with a backslash. Thus, in + + sed "s/$user\$/root/" file + + the shell interpolates $user and sed interprets \$ as the symbol + for end-of-line. + + (2) Another method--somewhat less readable--is to concatenate the + script with 'single quotes' where the $ should not be interpolated + and "double quotes" where variable interpolation should occur. To + demonstrate using the preceding script: + + sed "s/$user"'$/root/' file + + Solution #1 seems easier to remember. In either case, we search for + the user's name (stored in a variable called $user) when it occurs + at the end of the line ($), and substitute the word "root" in all + matches. + + For longer shell scripts, it is sometimes useful to begin with + single quote marks ('), close them upon encountering the variable, + enclose the variable name in double quotes ("), and resume with + single quotes, closing them at the end of the sed script. Example: + + #! /bin/sh + # sed script to illustrate 'quote'"matching"'usage' + FROM='abcdefgh' + TO='ABCDEFGH' + sed -e ' + y/'"$FROM"'/'"$TO"'/; # note the quote pairing + # some more commands go here . . . + # last line is a single quote mark + ' + + Thus, each variable named $FROM is replaced by $TO, and the single + quotes are used to glue the multiple lines together in the script. + (See also section 4.10, "How do I handle shell quoting in sed?") + +4.30.2. - on MS-DOS and 4DOS platforms + + Under 4DOS and MS-DOS version 7.0 (Win95) or 7.10 (Win95 OSR2), + environment variables can be accessed from the command prompt. + Under MS-DOS v6.22 and below, environment variables can only be + accessed from within batch files. Environment variables should be + enclosed between percent signs and are case-insensitive; i.e., + %USER% or %user% will display the USER variable. To generate a true + percent sign, just enter it twice. + + DOS versions of sed require that sed scripts be enclosed by double + quote marks "..." (not single quotes!) if the script contains + embedded tabs, spaces, redirection arrows or the vertical bar. In + fact, if the input for sed comes from piping, a sed script should + not contain a vertical bar, even if it is protected by double + quotes (this seems to be bug in the normal MS-DOS syntax). Thus, + + echo blurk | sed "s/^/ |foo /" # will cause an error + sed "s/^/ |foo /" blurk.txt # will work as expected + + Using DOS environment variables which contain DOS path statements + (such as a TMP variable set to "C:\TEMP") within sed scripts is + discouraged because sed will interpret the backslash '\' as a + metacharacter to "quote" the next character, not as a normal + symbol. Thus, + + sed "s/^/%TMP% /" somefile.txt + + will not prefix each line with (say) "C:\TEMP ", but will prefix + each line with "C:TEMP "; sed will discard the backslash, which is + probably not what you want. Other variables such as %PATH% and + %COMSPEC% will also lose the backslash within sed scripts. + + Environment variables which do not use backslashes are usually + workable. Thus, all the following should work without difficulty, + if they are invoked from within DOS batch files: + + sed "s/=username=/%USER%/g" somefile.txt + echo %FILENAME% | sed "s/\.TXT/.BAK/" + grep -Ei "%string%" somefile.txt | sed "s/^/ /" + + while from either the DOS prompt or from within a batch file, + + sed "s/%%/ percent/g" input.fil >output.fil + + will replace each percent symbol in a file with " percent" (adding + the leading space for readability). + +4.31. How do I export or pass variables back into the environment? + +4.31.1. - on Unix platforms + + Suppose that line #1, word #2 of the file 'terminals' contains a + value to be put in your TERM environment variable. Sed cannot + export variables directly to the shell, but it can pass strings to + shell commands. To set a variable in the Bourne shell: + + TERM=`sed 's/^[^ ][^ ]* \([^ ][^ ]*\).*/\1/;q' terminals`; + export TERM + + If the second word were "Wyse50", this would send the shell command + "TERM=Wyse50". + +4.31.2. - on MS-DOS or 4DOS platforms + + Sed cannot directly manipulate the environment. Under DOS, only + batch files (.BAT) can do this, using the SET instruction, since + they are run directly by the command shell. Under 4DOS, special + 4DOS commands (such as ESET) can also alter the environment. + + Under DOS or 4DOS, sed can select a word and pass it to the SET + command. Suppose you want the 1st word of the 2nd line of MY.DAT + put into an environment variable named %PHONE%. You might do this: + + @echo off + sed -n "2 s/^\([^ ][^ ]*\) .*/SET PHONE=\1/p;3q" MY.DAT > GO_.BAT + call GO_.BAT + echo The environment variable for PHONE is %PHONE% + :: cleanup + del GO_.BAT + + The sed script assumes that the first character on the 2nd line is + not a space and uses grouping \(...\) to save the first string of + non-space characters as \1 for the RHS. In writing any batch files, + make sure that output filenames such as GO_.BAT don't overwrite + preexisting files of the same name. + +4.32. How do I handle Unix shell quoting in sed? + + To embed a literal single quote (') in a script, use (a) or (b): + + (a) If possible, put the script in double quotes: + + sed "s/cannot/can't/g" file + + (b) If the script must use single quotes, then close-single-quote + the script just before the SPECIAL single quote, prefix the single + quote with a backslash, and use a 2nd pair of single quotes to + finish marking the script. Thus: + + sed 's/cannot$/can'\''t/g' file + + Though this looks hard to read, it breaks down to 3 parts: + + 's/cannot$/can' \' 't/g' + --------------- -- ----- + + To embed a literal double quote (") in a script, use (a) or (b): + + (a) If possible, put the script in single quotes. You don't need to + prefix the double quotes with anything. Thus: + + sed 's/14"/fourteen inches/g' file + + (b) If the script must use double quotes, then prefix the SPECIAL + double quote with a backslash (\). Thus, + + sed "s/$length\"/$length inches/g" file + + To embed a literal backslash (\) into a script, enter it twice: + + sed 's/C:\\DOS/D:\\DOS/g' config.sys + + FILES, DIRECTORIES, AND PATHS + +4.40. How do I read (insert/add) a file at the top of a textfile? + + Normally, adding a "header" file to the top of a "body" file is + done from the command prompt before passing the file on to sed. + (MS-DOS below version 6.0 must use COPY and DEL instead of MOVE in + the following example.) + + copy header.txt+body temp # MS-DOS command 1 + echo Y | move temp body # MS-DOS command 2 + # + cat header.txt body >temp; mv temp body # Unix commands + + However, if inserting the file must occur within sed, there is a + way. The sed command "1 r header.txt" will not work; it will print + line 1 and then insert "header.txt" between lines 1 and 2. The + following script solves this problem; however, there must be at + least 2 lines in the target file for the script to work properly. + + # sed script to insert "header.txt" above the first line + 1{h; r header.txt + D; } + 2{x; G; } + #---end of sed script--- + +4.41. How do I make substitutions in every file in a directory, or in + a complete directory tree? + +4.41.1. - ssed and Perl solution + + The best solution for multiple files in a single directory is to + use ssed or gsed v4.0 or higher: + + sed -i.BAK 's|foo|bar|g' files # -i does in-place replacement + + If you don't have ssed, there is a similar solution in Perl. (Yes, + we know this is a FAQ file for sed, not perl, but perl is more + common than ssed for many users.) + + perl -pi.bak -e 's|foo|bar|g' files # or + perl -pi.bak -e 's|foo|bar|g' `find /pathname -name "filespec"` + + For each file in the filelist, sed (or Perl) renames the source + file to "filename.bak"; the modified file gets the original + filename. Remove '.bak' if you don't need backup copies. (Note the + use of "s|||" instead of "s///" here, and in the scripts below. The + vertical bars in the 's' command let you replace '/some/path' with + '/another/path', accommodating slashes in the LHS and RHS.) + + To recurse directories in Unix or GNU/Linux: + + # We use xargs to prevent passing too many filenames to sed, but + # this command will fail if filenames contain spaces or newlines. + find /my/path -name '*.ht' -print | xargs sed -i.BAK 's|foo|bar|g' + + To recurse directories under Windows 2000 (CMD.EXE or COMMAND.COM): + + # This syntax isn't supported under Windows 9x COMMAND.COM + for /R c:\my\path %f in (*.htm) do sed -i.BAK "s|foo|bar|g" %f + +4.41.2. - Unix solution + + For all files in a single directory, assuming they end with *.txt + and you have no files named "[anything].txt.bak" already, use a + shell script: + + #! /bin/sh + # Source files are saved as "filename.txt.bak" in case of error + # The '&&' after cp is an additional safety feature + for file in *.txt + do + cp $file $file.bak && + sed 's|foo|bar|g' $file.bak >$file + done + + To do an entire directory tree, use the Unix utility find, like so + (thanks to Jim Dennis for this script): + + #! /bin/sh + # filename: replaceall + # Backup files are NOT saved in this script. + find . -type f -name '*.txt' -print | while read i + do + sed 's|foo|bar|g' $i > $i.tmp && mv $i.tmp $i + done + + This previous shell script recurses through the directory tree, + finding only files in the directory (not symbolic links, which will + be encountered by the shell command "for file in *.txt", above). To + preserve file permissions and make backup copies, use the 2-line cp + routine of the earlier script instead of "sed ... && mv ...". By + replacing the sed command 's|foo|bar|g' with something like + + sed "s|$1|$2|g" ${i}.bak > $i + + using double quotes instead of single quotes, the user can also + employ positional parameters on the shell script command tail, thus + reusing the script from time to time. For example, + + replaceall East West + + would modify all your *.txt files in the current directory. + +4.41.3. - DOS solution: + + MS-DOS users should use two batch files like this: + + @echo off + :: MS-DOS filename: REPLACE.BAT + :: + :: Create a destination directory to put the new files. + :: Note: The next command will fail under Novel Netware + :: below version 4.10 unless "SHOW DOTS=ON" is active. + if not exist .\NEWFILES\NUL mkdir NEWFILES + for %%f in (*.txt) do CALL REPL_2.BAT %%f + echo Done!! + :: ---End of first batch file--- + + @echo off + :: MS-DOS filename: REPL_2.BAT + :: + sed "s/foo/bar/g" %1 > NEWFILES\%1 + :: ---End of the second batch file--- + + When finished, the current directory contains all the original + files, and the newly-created NEWFILES subdirectory contains the + modified *.TXT files. Do not attempt a command like + + for %%f in (*.txt) do sed "s/foo/bar/g" %%f >NEWFILES\%%f + + under any version of MS-DOS because the output filename will be + created as a literal '%f' in the NEWFILES directory before the + %%f is expanded to become each filename in (*.txt). This occurs + because MS-DOS creates output filenames via redirection commands + before it expands "for..in..do" variables. + + To recurse through an entire directory tree in MS-DOS requires a + batch file more complex than we have room to describe. Examine the + file SWEEP.BAT in Timo Salmi's great archive of batch tricks, + located at (this file is + regularly updated). Another alternative is to get an external + program designed for directory recursion. Here are some recommended + programs for directory recursion. The first one, FORALL, runs under + either OS/2 or DOS. Unfortunately, none of these supports Win9x + long filenames. + + http://hobbes.nmsu.edu/pub/os2/util/disk/forall72.zip + ftp://garbo.uwasa.fi/pc/filefind/target15.zip + +4.42. How do I replace "/some/UNIX/path" in a substitution? + + Technically, the normal meaning of the slash can be disabled by + prefixing it with a backslash. Thus, + + sed 's/\/some\/UNIX\/path/\/a\/new\/path/g' files + + But this is hard to read and write. There is a better solution. + The s/// substitution command allows '/' to be replaced by any + other character (including spaces or alphanumerics). Thus, + + sed 's|/some/UNIX/path|/a/new/path|g' files + + and if you are using variable names in a Unix shell script, + + sed "s|$OLDPATH|$NEWPATH|g" oldfile >newfile + +4.43. How do I replace "C:\SOME\DOS\PATH" in a substitution? + + For MS-DOS users, every backslash must be doubled. Thus, to replace + "C:\SOME\DOS\PATH" with "D:\MY\NEW\PATH": + + sed "s|C:\\SOME\\DOS\\PATH|D:\\MY\\NEW\\PATH|g" infile >outfile + + Remember that DOS pathnames are not case sensitive and can appear + in upper or lower case in the input file. If this concerns you, use + a version of sed which can ignore case when matching (gsed, ssed, + sedmod, sed16). + + @echo off + :: sample MS-DOS batch file to alter path statements + :: requires GNU sed with the /i flag for s/// + set old=C:\\SOME\\DOS\\PATH + set new=D:\\MY\\NEW\\PATH + gsed "s|%old%|%new%|gi" infile >outfile + :: or + :: sedmod -i "s|%old%|%new%|g" infile >outfile + set old= + set new= + + Also, remember that under Windows long filenames may be stored in + two formats: e.g., as "C:\Program Files" or as "C:\PROGRA~1". + +4.44. How do I emulate file-includes, using sed? + + Given an input file with file-include statements, similar to + C-style includes or "server-side includes" (SSI) of this format: + + This is the source file. It's short. + Its name is simply 'source'. See the script below. + + And this is any amount of text between + + This is the last line of the file. + + How do we direct sed to import/insert whichever files are at the + point of the 'file="filename"' token? First, use this file: + + #n + # filename: incl.sed + # Comments supported by GNU sed or ssed. Leading '#n' should + # be on line 1, columns 1-2 of the line. + /