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| Newer page: | version 6 | Last edited on Thursday, October 21, 2004 5:18:25 pm | by AristotlePagaltzis | |
| Older page: | version 5 | Last edited on Sunday, August 17, 2003 4:23:12 am | by AristotlePagaltzis | Revert |
@@ -1,527 +1 @@
-!!!Bzip2 mini-HOWTO
-
-!!David Fetter,
-david@fetter.org v2.00, 22 August 1999
-
-
-----
-
-!!1. Introduction
-
-
-Bzip2 is a groovy new algorithm for compressing data. It generally makes files that are 60-70% of the size of their gzip'd counterparts.
-
-This document will take you through a few common applications for bzip2.
-
-Future versions of the document will have applications of libbzip2, the bzip2 C library which bzip2's author, Julian Seward has kindly written. The bzip2 manual, which includes low-level information about the library, can be found here: bzip2(1).
-
-Future versions of the document may also include a summary of the discussion over whether (and how) bzip2 should be used in the Linux kernel.
-
-----
-
-!! 2. Getting bzip2
-
-
-Bzip2's home page is at http://sources.redhat.com/bzip2/.
-
-
-!! 2.2 Getting bzip2 precompiled binaries
-
-
-
-See the home sites.
-
-
-
-
-!!2.3 Getting bzip2 sources
-
-
-
-They come from the Official sites (see
-Getting Bzip2
-for where.
-
-
-
-
-!!2.4 Compiling bzip2 for your machine
-
-
-
-__If you have gcc 2.7.*__, change the line that reads
-
-
- CFLAGS = -O3 -fomit-frame-pointer -funroll-loops
-
-
-
-
-to
-
-
- CFLAGS = -O2 -fomit-frame-pointer
-
-
-
-
-that is, replace -O3 with -O2 and drop the -funroll-loops. You may also wish to add any -m* flags (like -m486, for example) you use when compiling kernels.
-
-
-Avoiding -funroll-loops is the most important part, since this will
-cause many gcc 2.7's to generate wrong code, and all gcc 2.7's to
-generate slower and larger code. For other compilers (lcc, egcs,
-gcc 2.8.x) the default CFLAGS are fine.
-
-
-After that, just make it
-and install it per the README.
-
-
-
-----
-
-!!3. Using bzip2 by itself
-
-
-Read the Fine Manual Page :)
-
-
-
-----
-
-!! 4. Using bzip2 with tar
-
-
-Listed below are three ways to use bzip2 with tar, namely
-
-!!4.1 Easiest to set up:
-
-
-
-This method requires no setup at all. To un-tar the bzip2'd tar archive,
-foo.tar.bz2 in the current directory, do
-
-
- /path/to/bzip2 -cd foo.tar.bz2 | tar xf -
-
-
-or
-
-
- tar --use-compress-prog=bzip2 xf foo.tar.bz2
-
-
-
-
-
-
-
-These work, but can be a
[PITA
] to type often.
-
-
-
-
-!!4.2 Easy to set up, fairly easy to use, no need for root privileges:
-
-
-
-Thanks to
-Leonard Jean-Marc for the tip. Thanks also to
-Alessandro Rubini for
-differentiating bash from the csh's.
-
-
-
-
-
-In your .bashrc, you can put in a line like this:
-
-
- alias btar='tar --use-compress-program /usr/local/bin/bzip2 '
-
-
-
-
-
-
-
-In your .tcshrc, or .cshrc, the analogous line looks like this:
-
-
- alias btar 'tar --use-compress-program /usr/local/bin/bzip2'
-
-
-
-
-
-
-!!4.3 Also easy to use, but needs root access.
-
-
-
-Update your tar to GNU's newest version, which is currently 1.13.10.
-It can be found at
-GNU's ftp site or any mirror.
-
-
-
-----
-
-!! 5. Using bzip2 with less
-
-
-To uncompress bzip2'd files on the fly, i.e. to be able to use "less"
-on them without first bunzip2'ing them, you can make a lesspipe.sh (man
-less) like this:
-
- #!/bin/sh
- # This is a preprocessor for 'less'. It is used when this environment
- # variable is set: LESSOPEN="|lesspipe.sh %s"
- case "$1" in
- *.tar) tar tvvf $1 2>/dev/null ;; # View contents of various tar'd files
- *.tgz) tar tzvvf $1 2>/dev/null ;;
- # This one work for the unmodified version of tar:
- *.tar.bz2) bzip2 -cd $1 $1 2>/dev/null | tar tvvf - ;;
- #This one works with the patched version of tar:
- # *.tar.bz2) tyvvf $1 2>/dev/null ;;
- *.tar.gz) tar tzvvf $1 2>/dev/null ;;
- *.tar.Z) tar tzvvf $1 2>/dev/null ;;
- *.tar.z) tar tzvvf $1 2>/dev/null ;;
- *.bz2) bzip2 -dc $1 2>/dev/null ;; # View compressed files correctly
- *.Z) gzip -dc $1 2>/dev/null ;;
- *.z) gzip -dc $1 2>/dev/null ;;
- *.gz) gzip -dc $1 2>/dev/null ;;
- *.zip) unzip -l $1 2>/dev/null ;;
- *.1|*.2|*.3|*.4|*.5|*.6|*.7|*.8|*.9|*.n|*.man) FILE=`file -L $1` ; # groff src
- FILE=`echo $FILE | cut -d ' ' -f 2`
- if [[ "$FILE" = "troff" ]; then
- groff -s -p -t -e -Tascii -mandoc $1
- fi ;;
- *) cat $1 2>/dev/null ;;
- # *) FILE=`file -L $1` ; # Check to see if binary, if so -- view with 'strings'
- # FILE1=`echo $FILE | cut -d ' ' -f 2`
- # FILE2=`echo $FILE | cut -d ' ' -f 3`
- # if [[ "$FILE1" = "Linux/i386" -o "$FILE2" = "Linux/i386" \
- # -o "$FILE1" = "ELF" -o "$FILE2" = "ELF" ]; then
- # strings $1
- # fi ;;
- esac
-
-
-----
-
-!!6. Using bzip2 with emacs
-
-!!6.1 Changing emacs for everyone:
-
-
-
-I've written the following patch to jka-compr.el which adds bzip2 to
-auto-compression-mode.
-
-
-__Disclaimer:__ I have only tested this with emacs-20.2, but have
-no reason to believe that a similar approach won't work with other versions.
-
-
-To use it,
-
-
- #Go to the emacs-20.2/lisp source directory (wherever you untarred it)
-
-
- #Put the patch below in a file called jka-compr.el.diff (it should
- be alone in that file ;).
-
-
- #Do
- patch < jka-compr.el.diff
- #
- #Start emacs, and do
- M-x byte-compile-file jka-compr.el
- #
- #Leave emacs.
- #
- #Move your original jka-compr.elc to a safe place in case of bugs.
- #
- #Replace it with the new jka-compr.elc.
- #
- #Have fun!
- #
-
- --- jka-compr.el Sat Jul 26 17:02:39 1997
- +++ jka-compr.el.new Thu Feb 5 17:44:35 1998
- @@ -44,7 +44,7 @@
- ;; The variable, jka-compr-compression-info-list can be used to
- ;; customize jka-compr to work with other compression programs.
- ;; The default value of this variable allows jka-compr to work with
- -;; Unix compress and gzip.
- +;; Unix compress and gzip. David Fetter added bzip2 support :)
- ;;
- ;; If you are concerned about the stderr output of gzip and other
- ;; compression/decompression programs showing up in your buffers, you
- @@ -121,7 +121,9 @@
- ;;; I have this defined so that .Z files are assumed to be in unix
- -;;; compress format; and .gz files, in gzip format.
- +;;; compress format; and .gz files, in gzip format, and .bz2 files,
- +;;; in the snappy new bzip2 format from http://www.muraroa.demon.co.uk.
- +;;; Keep up the good work, people!
- (defcustom jka-compr-compression-info-list
- ;;[[regexp
- ;; compr-message compr-prog compr-args
- @@ -131,6 +133,10 @@
- "compressing" "compress" ("-c")
- "uncompressing" "uncompress" ("-c")
- nil t]
- + [["\\.bz2\\'"
- + "bzip2ing" "bzip2" ("")
- + "bunzip2ing" "bzip2" ("-d")
- + nil t]
- [["\\.tgz\\'"
- "zipping" "gzip" ("-c" "-q")
- "unzipping" "gzip" ("-c" "-q" "-d")
-
-
-
-
-
-!!6.2 Changing emacs for one person:
-
-
-
-Thanks for this one go to Ulrik Dickow,
-ukd@kampsax.dk, Systems Programmer at Kampsax Technology:
-
-
-To make it so you can use bzip2 automatically when you aren't the
-sysadmin, just add the following to your .emacs file.
-
-
-
-
- ;; Automatic (un)compression on loading/saving files (gzip(1) and similar)
- ;; We start it in the off state, so that bzip2(1) support can be added.
- ;; Code thrown together by Ulrik Dickow for ~/.emacs with Emacs 19.34.
- ;; Should work with many older and newer Emacsen too. No warranty though.
- ;;
- (if (fboundp 'auto-compression-mode) ; Emacs 19.30+
- (auto-compression-mode )
- (require 'jka-compr)
- (toggle-auto-compression ))
- ;; Now add bzip2 support and turn auto compression back on.
- (add-to-list 'jka-compr-compression-info-list
- [["\\.bz2\\(~\\|\\.~[[-9]+~\\)?\\'"
- "zipping" "bzip2" ()
- "unzipping" "bzip2" ("-d")
- nil t])
- (toggle-auto-compression 1 t)
-
-
-
-
-----
-
-!!7. Using bzip2 with wu-ftpd
-
-
-Thanks to Arnaud Launay for this bandwidth saver. The following should
-go in /etc/ftpconversions to do on-the-fly compressions and decompressions
-with bzip2. Make sure that the paths (like /bin/compress) are right.
-
-
-
-
- :.Z: : :/bin/compress -d -c %s:T_REG|T_ASCII:O_UNCOMPRESS:UNCOMPRESS
- : : :.Z:/bin/compress -c %s:T_REG:O_COMPRESS:COMPRESS
- :.gz: : :/bin/gzip -cd %s:T_REG|T_ASCII:O_UNCOMPRESS:GUNZIP
- : : :.gz:/bin/gzip -9 -c %s:T_REG:O_COMPRESS:GZIP
- :.bz2: : :/bin/bzip2 -cd %s:T_REG|T_ASCII:O_UNCOMPRESS:BUNZIP2
- : : :.bz2:/bin/bzip2 -9 -c %s:T_REG:O_COMPRESS:BZIP2
- : : :.tar:/bin/tar -c -f - %s:T_REG|T_DIR:O_TAR:TAR
- : : :.tar.Z:/bin/tar -c -Z -f - %s:T_REG|T_DIR:O_COMPRESS|O_TAR:TAR+COMPRESS
- : : :.tar.gz:/bin/tar -c -z -f - %s:T_REG|T_DIR:O_COMPRESS|O_TAR:TAR+GZIP
- : : :.tar.bz2:/bin/tar -c -y -f - %s:T_REG|T_DIR:O_COMPRESS|O_TAR:TAR+BZIP2
-
-
-
-
-----
-
-!!8. Using bzip2 with grep
-
-
-The following utility, which I call bgrep, is a slight modification
-of the zgrep which comes with Linux. You can use it to grep through
-files without bunzip2'ing them first.
-
-
-
- #!/bin/sh
- # bgrep -- a wrapper around a grep program that decompresses files as needed
- PATH="/usr/bin:$PATH"; export PATH
- prog=`echo $0 | sed 's|.*/||'`
- case "$prog" in
- *egrep) grep=${EGREP-egrep} ;;
- *fgrep) grep=${FGREP-fgrep} ;;
- *) grep=${GREP-grep} ;;
- esac
- pat=""
- while test $# -ne ; do
- case "$1" in
- -e | -f) opt="$opt $1"; shift; pat="$1"
- if test "$grep" = grep; then # grep is buggy with -e on SVR4
- grep=egrep
- fi;;
- -*) opt="$opt $1";;
- *) if test -z "$pat"; then
- pat="$1"
- else
- break;
- fi;;
- esac
- shift
- done
- if test -z "$pat"; then
- echo "grep through bzip2 files"
- echo "usage: $prog [[grep_options] pattern [[files]"
- exit 1
- fi
- list=
- silent=
- op=`echo "$opt" | sed -e 's/ //g' -e 's/-//g'`
- case "$op" in
- *l*) list=1
- esac
- case "$op" in
- *h*) silent=1
- esac
- if test $# -eq ; then
- bzip2 -cd | $grep $opt "$pat"
- exit $?
- fi
- res=
- for i do
- if test $list -eq 1; then
- bzip2 -cdfq "$i" | $grep $opt "$pat" > /dev/null && echo $i
- r=$?
- elif test $# -eq 1 -o $silent -eq 1; then
- bzip2 -cd "$i" | $grep $opt "$pat"
- r=$?
- else
- bzip2 -cd "$i" | $grep $opt "$pat" | sed "s|^|${i}:|"
- r=$?
- fi
- test "$r" -ne 0 && res="$r"
- done
- exit $res
-
-
-
-
-----
-
-!!9. Using bzip2 with Netscape under the X.
-
-
-tenthumbs@cybernex.net says:
-
-I also found a way to get Linux Netscape to use bzip2 for
-Content-Encoding just as it uses gzip. Add this to $HOME/.Xdefaults or
-$HOME/.Xresources
-
-I use the -s option because I would rather trade some decompressing
-speed for RAM usage. You can leave the option out if you want to.
-
-
-
-
-
- Netscape*encodingFilters: \
- x-compress : : .Z : uncompress -c \n\
- compress : : .Z : uncompress -c \n\
- x-gzip : : .z,.gz : gzip -cdq \n\
- gzip : : .z,.gz : gzip -cdq \n\
- x-bzip2 : : .bz2 : bzip2 -ds \n
-
-
-
-
-----
-
-!!10. Using bzip2 to recompress other compression formats
-
-
-The following perl program takes files compressed
-in other formats (.tar.gz, .tgz. .tar.Z, and .Z for this iteration) and repacks
-them for better compression. The perl source has all kinds of neat
-documentation on what it does and how it does what it does. This latest
-version takes files as input on the command line. Without command line
-arguments, it tries to repack every file in the current working
-directory.
-
-
-
-
- #!/usr/bin/perl -w
- #######################################################
- # #
- # This program takes compressed and gzipped programs #
- # in the current directory and turns them into bzip2 #
- # format. It handles the .tgz extension in a #
- # reasonable way, producing a .tar.bz2 file. #
- # #
- #######################################################
- $counter = ;
- $saved_bytes = ;
- $totals_file = '/tmp/machine_bzip2_total';
- $machine_bzip2_total = ;
- @raw = (defined @ARGV)?@ARGV:<*>;
- foreach(@raw) {
- next if /^bzip/;
- next unless /\.(tgz|gz|Z)$/;
- push @files, $_;
- }
- $total = scalar(@files);
- foreach (@files) {
- if (/tgz$/) {
- ($new=$_) =~ s/tgz$/tar.bz2/;
- } else {
- ($new=$_) =~ s/\.g?z$/.bz2/i;
- }
- $orig_size = (stat $_)[[7];
- ++$counter;
- print "Repacking $_ ($counter/$total)...\n";
- if ((system "gzip -cd $_ |bzip2 >$new") == ) {
- $new_size = (stat $new)[[7];
- $factor = int(100*$new_size/$orig_size+.5);
- $saved_bytes += $orig_size-$new_size;
- print "$new is about $factor% of the size of $_. :",($factor<100)?')':'(',"\n";
- unlink $_;
- } else {
- print "Arrgghh! Something happened to $_: $!\n";
- }
- }
- print "You've "
- , ($saved_bytes>=)?"saved ":"lost "
- , abs($saved_bytes)
- , " bytes of storage space :"
- , ($saved_bytes>=)?")":"("
- , "\n"
- ;
- unless (-e '/tmp/machine_bzip2_total') {
- system ('echo "" >/tmp/machine_bzip2_total');
- system ('chmod', '0666', '/tmp/machine_bzip2_total');
- }
- chomp($machine_bzip2_total = `cat $totals_file`);
- open TOTAL, ">$totals_file"
- or die "Can't open system-wide total: $!";
- $machine_bzip2_total += $saved_bytes;
- print TOTAL $machine_bzip2_total;
- close TOTAL;
- print "That's a machine-wide total of ",`cat $totals_file`," bytes saved
.\n";
-
-
-
-
-----
+Describe
[HowToBzip2
] here
.
