Сжатие страниц документации man и info

Программы чтения Man и info могут прозрачно обрабатывать страницы, сжатые gzip или bzip2, за счет чего вы можете освободить некоторое дисковое пространство, оставив вашу документацию доступной. Хотя это не просто; директории man содержат ссылки—жесткие и символические —которые срывают такие простые идеи, как рекурсивный вызов gzip на них. Лучший путь для этого - использование скрипта, описанного ниже.

cat > /usr/sbin/compressdoc << "EOF" #!/bin/bash # VERSION: 20050112.0027 # # Compress (with bzip2 or gzip) all man pages in a hierarchy and # update symlinks - By Marc Heerdink <marc @ koelkast.net> # # Modified to be able to gzip or bzip2 files as an option and to deal # with all symlinks properly by Mark Hymers <markh @ linuxfromscratch.org> # # Modified 20030930 by Yann E. Morin <yann.morin.1998 @ anciens.enib.fr> # to accept compression/decompression, to correctly handle hard-links, # to allow for changing hard-links into soft- ones, to specify the # compression level, to parse the man.conf for all occurrences of MANPATH, # to allow for a backup, to allow to keep the newest version of a page. # # Modified 20040330 by Tushar Teredesai to replace $0 by the name of the # script. # (Note: It is assumed that the script is in the user's PATH) # # Modified 20050112 by Randy McMurchy to shorten line lengths and # correct grammar errors. # # TODO: # - choose a default compress method to be based on the available # tool : gzip or bzip2; # - offer an option to automagically choose the best compression # methed on a per page basis (eg. check which of # gzip/bzip2/whatever is the most effective, page per page); # - when a MANPATH env var exists, use this instead of /etc/man.conf # (useful for users to (de)compress their man pages; # - offer an option to restore a previous backup; # - add other compression engines (compress, zip, etc?). Needed? # Funny enough, this function prints some help. function help () { if [ -n "$1" ]; then echo "Unknown option : $1" fi ( echo "Usage: $MY_NAME <comp_method> [options] [dirs]" && \ cat << EOT Where comp_method is one of : --gzip, --gz, -g --bzip2, --bz2, -b Compress using gzip or bzip2. --decompress, -d Decompress the man pages. --backup Specify a .tar backup shall be done for all directories. In case a backup already exists, it is saved as .tar.old prior to making the new backup. If a .tar.old backup exists, it is removed prior to saving the backup. In backup mode, no other action is performed. And where options are : -1 to -9, --fast, --best The compression level, as accepted by gzip and bzip2. When not specified, uses the default compression level for the given method (-6 for gzip, and -9 for bzip2). Not used when in backup or decompress modes. --force, -F Force (re-)compression, even if the previous one was the same method. Useful when changing the compression ratio. By default, a page will not be re-compressed if it ends with the same suffix as the method adds (.bz2 for bzip2, .gz for gzip). --soft, -S Change hard-links into soft-links. Use with _caution_ as the first encountered file will be used as a reference. Not used when in backup mode. --hard, -H Change soft-links into hard-links. Not used when in backup mode. --conf=dir, --conf dir Specify the location of man.conf. Defaults to /etc. --verbose, -v Verbose mode, print the name of the directory being processed. Double the flag to turn it even more verbose, and to print the name of the file being processed. --fake, -f Fakes it. Print the actual parameters compman will use. dirs A list of space-separated _absolute_ pathnames to the man directories. When empty, and only then, parse ${MAN_CONF}/man.conf for all occurrences of MANPATH. Note about compression: There has been a discussion on blfs-support about compression ratios of both gzip and bzip2 on man pages, taking into account the hosting fs, the architecture, etc... On the overall, the conclusion was that gzip was much more efficient on 'small' files, and bzip2 on 'big' files, small and big being very dependent on the content of the files. See the original post from Mickael A. Peters, titled "Bootable Utility CD", dated 20030409.1816(+0200), and subsequent posts: http://linuxfromscratch.org/pipermail/blfs-support/2003-April/038817.html On my system (x86, ext3), man pages were 35564KB before compression. gzip -9 compressed them down to 20372KB (57.28%), bzip2 -9 got down to 19812KB (55.71%). That is a 1.57% gain in space. YMMV. What was not taken into consideration was the decompression speed. But does it make sense to? You gain fast access with uncompressed man pages, or you gain space at the expense of a slight overhead in time. Well, my P4-2.5GHz does not even let me notice this... :-) EOT ) | less } # This function checks that the man page is unique amongst bzip2'd, # gzip'd and uncompressed versions. # $1 the directory in which the file resides # $2 the file name for the man page # Returns 0 (true) if the file is the latest and must be taken care of, # and 1 (false) if the file is not the latest (and has therefore been # deleted). function check_unique () { # NB. When there are hard-links to this file, these are # _not_ deleted. In fact, if there are hard-links, they # all have the same date/time, thus making them ready # for deletion later on. # Build the list of all man pages with the same name DIR=$1 BASENAME=`basename "${2}" .bz2` BASENAME=`basename "${BASENAME}" .gz` GZ_FILE="$BASENAME".gz BZ_FILE="$BASENAME".bz2 # Look for, and keep, the most recent one LATEST=`(cd "$DIR"; ls -1rt "${BASENAME}" "${GZ_FILE}" "${BZ_FILE}" \ 2>/dev/null | tail -n 1)` for i in "${BASENAME}" "${GZ_FILE}" "${BZ_FILE}"; do [ "$LATEST" != "$i" ] && rm -f "$DIR"/"$i" done # In case the specified file was the latest, return 0 [ "$LATEST" = "$2" ] && return 0 # If the file was not the latest, return 1 return 1 } # Name of the script MY_NAME=`basename $0` # OK, parse the command-line for arguments, and initialize to some # sensible state, that is: don't change links state, parse # /etc/man.conf, be most silent, search man.conf in /etc, and don't # force (re-)compression. COMP_METHOD= COMP_SUF= COMP_LVL= FORCE_OPT= LN_OPT= MAN_DIR= VERBOSE_LVL=0 BACKUP=no FAKE=no MAN_CONF=/etc while [ -n "$1" ]; do case $1 in --gzip|--gz|-g) COMP_SUF=.gz COMP_METHOD=$1 shift ;; --bzip2|--bz2|-b) COMP_SUF=.bz2 COMP_METHOD=$1 shift ;; --decompress|-d) COMP_SUF= COMP_LVL= COMP_METHOD=$1 shift ;; -[1-9]|--fast|--best) COMP_LVL=$1 shift ;; --force|-F) FORCE_OPT=-F shift ;; --soft|-S) LN_OPT=-S shift ;; --hard|-H) LN_OPT=-H shift ;; --conf=*) MAN_CONF=`echo $1 | cut -d '=' -f2-` shift ;; --conf) MAN_CONF="$2" shift 2 ;; --verbose|-v) let VERBOSE_LVL++ shift ;; --backup) BACKUP=yes shift ;; --fake|-f) FAKE=yes shift ;; --help|-h) help exit 0 ;; /*) MAN_DIR="${MAN_DIR} ${1}" shift ;; -*) help $1 exit 1 ;; *) echo "\"$1\" is not an absolute path name" exit 1 ;; esac done # Redirections case $VERBOSE_LVL in 0) # O, be silent DEST_FD0=/dev/null DEST_FD1=/dev/null VERBOSE_OPT= ;; 1) # 1, be a bit verbose DEST_FD0=/dev/stdout DEST_FD1=/dev/null VERBOSE_OPT=-v ;; *) # 2 and above, be most verbose DEST_FD0=/dev/stdout DEST_FD1=/dev/stdout VERBOSE_OPT="-v -v" ;; esac # Note: on my machine, 'man --path' gives /usr/share/man twice, once # with a trailing '/', once without. if [ -z "$MAN_DIR" ]; then MAN_DIR=`man --path -C "$MAN_CONF"/man.conf \ | sed 's/:/\\n/g' \ | while read foo; do dirname "$foo"/.; done \ | sort -u \ | while read bar; do echo -n "$bar "; done` fi # If no MANPATH in ${MAN_CONF}/man.conf, abort as well if [ -z "$MAN_DIR" ]; then echo "No directory specified, and no directory found with \`man --path'" exit 1 fi # Fake? if [ "$FAKE" != "no" ]; then echo "Actual parameters used:" echo -n "Compression.......: " case $COMP_METHOD in --bzip2|--bz2|-b) echo -n "bzip2";; --gzip|__gz|-g) echo -n "gzip";; --decompress|-d) echo -n "decompressing";; *) echo -n "unknown";; esac echo " ($COMP_METHOD)" echo "Compression level.: $COMP_LVL" echo "Compression suffix: $COMP_SUF" echo -n "Force compression.: " [ "foo$FORCE_OPT" = "foo-F" ] && echo "yes" || echo "no" echo "man.conf is.......: ${MAN_CONF}/man.conf" echo -n "Hard-links........: " [ "foo$LN_OPT" = "foo-S" ] && echo "convert to soft-links" || echo "leave as is" echo -n "Soft-links........: " [ "foo$LN_OPT" = "foo-H" ] && echo "convert to hard-links" || echo "leave as is" echo "Backup............: $BACKUP" echo "Faking (yes!).....: $FAKE" echo "Directories.......: $MAN_DIR" echo "Verbosity level...: $VERBOSE_LVL" exit 0 fi # If no method was specified, print help if [ -z "${COMP_METHOD}" -a "${BACKUP}" = "no" ]; then help exit 1 fi # In backup mode, do the backup solely if [ "$BACKUP" = "yes" ]; then for DIR in $MAN_DIR; do cd "${DIR}/.." DIR_NAME=`basename "${DIR}"` echo "Backing up $DIR..." > $DEST_FD0 [ -f "${DIR_NAME}.tar.old" ] && rm -f "${DIR_NAME}.tar.old" [ -f "${DIR_NAME}.tar" ] && mv "${DIR_NAME}.tar" "${DIR_NAME}.tar.old" tar -cfv "${DIR_NAME}.tar" "${DIR_NAME}" > $DEST_FD1 done exit 0 fi # I know MAN_DIR has only absolute path names # I need to take into account the localized man, so I'm going recursive for DIR in $MAN_DIR; do MEM_DIR=`pwd` cd "$DIR" for FILE in *; do # Fixes the case were the directory is empty if [ "foo$FILE" = "foo*" ]; then continue; fi # Fixes the case when hard-links see their compression scheme change # (from not compressed to compressed, or from bz2 to gz, or from gz # to bz2) # Also fixes the case when multiple version of the page are present, # which are either compressed or not. if [ ! -L "$FILE" -a ! -e "$FILE" ]; then continue; fi # Do not compress whatis files if [ "$FILE" = "whatis" ]; then continue; fi if [ -d "$FILE" ]; then cd "${MEM_DIR}" # Go back to where we ran "$0", # in case "$0"=="./compressdoc" ... # We are going recursive to that directory echo "-> Entering ${DIR}/${FILE}..." > $DEST_FD0 # I need not pass --conf, as I specify the directory to work on # But I need exit in case of error "$MY_NAME" ${COMP_METHOD} ${COMP_LVL} ${LN_OPT} ${VERBOSE_OPT} \ ${FORCE_OPT} "${DIR}/${FILE}" || exit 1 echo "<- Leaving ${DIR}/${FILE}." > $DEST_FD1 cd "$DIR" # Needed for the next iteration of the loop else # !dir if ! check_unique "$DIR" "$FILE"; then continue; fi # Check if the file is already compressed with the specified method BASE_FILE=`basename "$FILE" .gz` BASE_FILE=`basename "$BASE_FILE" .bz2` if [ "${FILE}" = "${BASE_FILE}${COMP_SUF}" \ -a "foo${FORCE_OPT}" = "foo" ]; then continue; fi # If we have a symlink if [ -h "$FILE" ]; then case "$FILE" in *.bz2) EXT=bz2 ;; *.gz) EXT=gz ;; *) EXT=none ;; esac if [ ! "$EXT" = "none" ]; then LINK=`ls -l "$FILE" | cut -d ">" -f2 \ | tr -d " " | sed s/\.$EXT$//` NEWNAME=`echo "$FILE" | sed s/\.$EXT$//` mv "$FILE" "$NEWNAME" FILE="$NEWNAME" else LINK=`ls -l "$FILE" | cut -d ">" -f2 | tr -d " "` fi if [ "$LN_OPT" = "-H" ]; then # Change this soft-link into a hard- one rm -f "$FILE" && ln "${LINK}$COMP_SUF" "${FILE}$COMP_SUF" chmod --reference "${LINK}$COMP_SUF" "${FILE}$COMP_SUF" else # Keep this soft-link a soft- one. rm -f "$FILE" && ln -s "${LINK}$COMP_SUF" "${FILE}$COMP_SUF" fi echo "Relinked $FILE" > $DEST_FD1 # else if we have a plain file elif [ -f "$FILE" ]; then # Take care of hard-links: build the list of files hard-linked # to the one we are {de,}compressing. # NB. This is not optimum has the file will eventually be # compressed as many times it has hard-links. But for now, # that's the safe way. inode=`ls -li "$FILE" | awk '{print $1}'` HLINKS=`find . \! -name "$FILE" -inum $inode` if [ -n "$HLINKS" ]; then # We have hard-links! Remove them now. for i in $HLINKS; do rm -f "$i"; done fi # Now take care of the file that has no hard-link # We do decompress first to re-compress with the selected # compression ratio later on... case "$FILE" in *.bz2) bunzip2 $FILE FILE=`basename "$FILE" .bz2` ;; *.gz) gunzip $FILE FILE=`basename "$FILE" .gz` ;; esac # Compress the file with the given compression ratio, if needed case $COMP_SUF in *bz2) bzip2 ${COMP_LVL} "$FILE" && chmod 644 "${FILE}${COMP_SUF}" echo "Compressed $FILE" > $DEST_FD1 ;; *gz) gzip ${COMP_LVL} "$FILE" && chmod 644 "${FILE}${COMP_SUF}" echo "Compressed $FILE" > $DEST_FD1 ;; *) echo "Uncompressed $FILE" > $DEST_FD1 ;; esac # If the file had hard-links, recreate those (either hard or soft) if [ -n "$HLINKS" ]; then for i in $HLINKS; do NEWFILE=`echo "$i" | sed s/\.gz$// | sed s/\.bz2$//` if [ "$LN_OPT" = "-S" ]; then # Make this hard-link a soft- one ln -s "${FILE}$COMP_SUF" "${NEWFILE}$COMP_SUF" else # Keep the hard-link a hard- one ln "${FILE}$COMP_SUF" "${NEWFILE}$COMP_SUF" fi # Really work only for hard-links. Harmless for soft-links chmod 644 "${NEWFILE}$COMP_SUF" done fi else # There is a problem when we get neither a symlink nor a plain # file. Obviously, we shall never ever come here... :-( echo -n "Whaooo... \"${DIR}/${FILE}\" is neither a symlink " echo "nor a plain file. Please check:" ls -l "${DIR}/${FILE}" exit 1 fi fi done # for FILE done # for DIR EOF chmod 755 /usr/sbin/compressdoc

Теперь, как root, вы можете выполнить compressdoc --bz2 для сжатия всех ваших страниц man. Вы можете так же запустить compressdoc --help для получения помощи о том, что этот скрипт может делать.

Не забудте так же, что некоторые программы, например X Window System и XEmacs, устанавливают свою документацию в нестандартные места (такие как /usr/X11R6/man и т.д.). Убедитесь, что добавили эти места в файл /etc/man.conf как секцию MANPATH=[/path].


... MANPATH=/usr/share/man MANPATH=/usr/local/man MANPATH=/usr/X11R6/man MANPATH=/opt/qt/doc/man ...

Обычно системы установки пакетов не сжимают страницы man/info, что означает, что вам необходимо будет опять запустить скрипт, если вы хотите иметь минимальный размер вашей документации. Так же заметьте, что запуск скрипта после обновления пакета является безопасным; когда вы имеете несколько версий страницы (например, одна сжатая и одна нет), более вероятно, что одна останется, а другая удалится.

Последнее обновление 2005-02-14 15:44:39 -0700