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diff --git a/doc/zutils.info b/doc/zutils.info index bf99e2d..2de6d3b 100644 --- a/doc/zutils.info +++ b/doc/zutils.info @@ -1,5 +1,4 @@ -This is zutils.info, produced by makeinfo version 4.13+ from -zutils.texi. +This is zutils.info, produced by makeinfo version 4.13+ from zutils.texi. INFO-DIR-SECTION Data Compression START-INFO-DIR-ENTRY @@ -12,7 +11,7 @@ File: zutils.info, Node: Top, Next: Introduction, Up: (dir) Zutils Manual ************* -This manual is for Zutils (version 1.8, 1 January 2019). +This manual is for Zutils (version 1.9, 27 June 2020). * Menu: @@ -29,10 +28,10 @@ This manual is for Zutils (version 1.8, 1 January 2019). * Concept index:: Index of concepts - Copyright (C) 2009-2019 Antonio Diaz Diaz. + Copyright (C) 2009-2020 Antonio Diaz Diaz. - This manual is free documentation: you have unlimited permission to -copy, distribute and modify it. + This manual is free documentation: you have unlimited permission to copy, +distribute, and modify it. File: zutils.info, Node: Introduction, Next: Common options, Prev: Top, Up: Top @@ -41,45 +40,45 @@ File: zutils.info, Node: Introduction, Next: Common options, Prev: Top, Up: ************** Zutils is a collection of utilities able to process any combination of -compressed and uncompressed files transparently. If any given file, -including standard input, is compressed, its decompressed content is -used. Compressed files are decompressed on the fly; no temporary files -are created. +compressed and uncompressed files transparently. If any file given, +including standard input, is compressed, its decompressed content is used. +Compressed files are decompressed on the fly; no temporary files are +created. - These utilities are not wrapper scripts but safer and more efficient -C++ programs. In particular the '--recursive' option is very efficient -in those utilities supporting it. + These utilities are not wrapper scripts but safer and more efficient C++ +programs. In particular the option '--recursive' is very efficient in those +utilities supporting it. -The utilities provided are zcat, zcmp, zdiff, zgrep, ztest and zupdate. -The formats supported are bzip2, gzip, lzip and xz. -Zutils uses external compressors. The compressor to be used for each -format is configurable at runtime. +The utilities provided are zcat, zcmp, zdiff, zgrep, ztest, and zupdate. +The formats supported are bzip2, gzip, lzip, and xz. +Zutils uses external compressors. The compressor to be used for each format +is configurable at runtime. zcat, zcmp, zdiff, and zgrep are improved replacements for the shell -scripts provided by GNU gzip. ztest is unique to zutils. zupdate is -similar to gzip's znew. +scripts provided by GNU gzip. ztest is unique to zutils. zupdate is similar +to gzip's znew. - NOTE: Bzip2 and lzip provide well-defined values of exit status, -which makes them safe to use with zutils. Gzip and xz may return -ambiguous warning values, making them less reliable back ends for -zutils. *Note compressor-requirements::. + NOTE: Bzip2 and lzip provide well-defined values of exit status, which +makes them safe to use with zutils. Gzip and xz may return ambiguous warning +values, making them less reliable back ends for zutils. *Note +compressor-requirements::. - FORMAT NOTE 1: The '--format' option allows the processing of a -subset of formats in recursive mode and when trying compressed file -names: 'zgrep foo -r --format=bz2,lz somedir somefile.tar'. + FORMAT NOTE 1: The option '--format' allows the processing of a subset +of formats in recursive mode and when trying compressed file names: +'zgrep foo -r --format=bz2,lz somedir somefile.tar'. - FORMAT NOTE 2: If the '--force-format' option is given, the files -are passed to the corresponding decompressor without verifying their -format, allowing for example the processing of compress'd (.Z) files -with gzip: 'zcmp --force-format=gz file.Z file.lz'. + FORMAT NOTE 2: If the option '--force-format' is given, the files are +passed to the corresponding decompressor without verifying their format, +allowing for example the processing of compress'd (.Z) files with gzip: +'zcmp --force-format=gz file.Z file.lz'. - LANGUAGE NOTE: Uncompressed = not compressed = plain data; it may -never have been compressed. Decompressed is used to refer to data which -have undergone the process of decompression. + LANGUAGE NOTE: Uncompressed = not compressed = plain data; it may never +have been compressed. Decompressed is used to refer to data which have +undergone the process of decompression. - Numbers given as arguments to options (positions, sizes) may be -followed by a multiplier and an optional 'B' for "byte". + Numbers given as arguments to options (positions, sizes) may be followed +by a multiplier and an optional 'B' for "byte". Table of SI and binary prefixes (unit multipliers): @@ -99,9 +98,9 @@ File: zutils.info, Node: Common options, Next: The zutilsrc file, Prev: Intro 2 Common options **************** -The following options are available in all the utilities. Rather than -writing identical descriptions for each of the programs, they are -described here. +The following options: are available in all the utilities. Rather than +writing identical descriptions for each of the programs, they are described +here. *Note Argument syntax: (arg_parser)Argument syntax. '-h' '--help' @@ -110,19 +109,19 @@ described here. '-V' '--version' - Print the version number on the standard output and exit. This - version number should be included in all bug reports. + Print the version number on the standard output and exit. This version + number should be included in all bug reports. '-M FORMAT_LIST' '--format=FORMAT_LIST' - Process only the formats listed in the comma-separated - FORMAT_LIST. Valid formats are 'bz2', 'gz', 'lz', 'xz' and 'un' - for 'uncompressed', meaning "any file name without a known - extension". This option excludes files based on extension, instead - of format, because it is more efficient. The exclusion only - applies to names generated automatically (for example when adding - extensions to a file name or when operating recursively on - directories). Files given in the command line are always processed. + Process only the formats listed in the comma-separated FORMAT_LIST. + Valid formats are 'bz2', 'gz', 'lz', 'xz', and 'un' for + 'uncompressed', meaning "any file name without a known extension". + This option excludes files based on extension, instead of format, + because it is more efficient. The exclusion only applies to names + generated automatically (for example when adding extensions to a file + name or when operating recursively on directories). Files given in the + command line are always processed. Each format in FORMAT_LIST enables file names with the following extensions: @@ -141,17 +140,20 @@ described here. '--gz=COMMAND' '--lz=COMMAND' '--xz=COMMAND' - Set program (may include arguments) to be used as (de)compressor - for the given format. The name of the program can't begin with - '-'. These options override the values set in 'zutilsrc'. The - compression program used must meet three requirements: + Set program to be used as (de)compressor for the corresponding format. + COMMAND may include arguments. For example '--lz='plzip --threads=2''. + The program set with '--lz' is used for both compression and + decompression. The other three are used only for decompression. The + name of the program can't begin with '-'. These options override the + values set in 'zutilsrc'. The compression program used must meet three + requirements: - 1. When called with the '-d' option, it must read compressed - data from the standard input and produce decompressed data on - the standard output. + 1. When called with the option '-d', it must read compressed data + from the standard input and produce decompressed data on the + standard output. - 2. If the '-q' option is passed to zutils, the compression - program must also accept it. + 2. If the option '-q' is passed to zutils, the compression program + must also accept it. 3. It must return 0 if no errors occurred, and a non-zero value otherwise. @@ -164,23 +166,23 @@ File: zutils.info, Node: The zutilsrc file, Next: Zcat, Prev: Common options, ******************* 'zutilsrc' is the runtime configuration file for zutils. In it you may -define the compressor name and options to be used for each format. The -'zutilsrc' file is optional; you don't need to install it in order to -run zutils. +define the compressor name and options to be used for each format. The +'zutilsrc' file is optional; you don't need to install it in order to run +zutils. - The compressors specified in the command line override those -specified in the 'zutilsrc' file. + The compressors specified in the command line override those specified +in the 'zutilsrc' file. You may copy the system 'zutilsrc' file '${sysconfdir}/zutilsrc' to -'$HOME/.zutilsrc' and customize these options as you like. The file -syntax is fairly obvious (and there are further instructions in it): +'$HOME/.zutilsrc' and customize these options as you like. The file syntax +is fairly obvious (and there are further instructions in it): 1. Any line beginning with '#' is a comment line. - 2. Each non-comment line defines the command to be used for the given - format, with the syntax: + 2. Each non-comment line defines the command to be used for the + corresponding format, with the syntax: <format> = <compressor> [options] - where <format> is one of 'bz2', 'gz', 'lz' or 'xz'. + where <format> is one of 'bz2', 'gz', 'lz', or 'xz'. File: zutils.info, Node: Zcat, Next: Zcmp, Prev: The zutilsrc file, Up: Top @@ -188,26 +190,26 @@ File: zutils.info, Node: Zcat, Next: Zcmp, Prev: The zutilsrc file, Up: Top 4 Zcat ****** -zcat copies each given file to standard output. If any given file is -compressed, its decompressed content is used. If a given file does not -exist, and its name does not end with one of the known extensions, zcat -tries the compressed file names corresponding to the formats supported. -If a file fails to decompress, zcat continues copying the rest of the -files. +zcat copies each FILE argument to standard output in sequence. If any file +given is compressed, its decompressed content is copied. If a file given +does not exist, and its name does not end with one of the known extensions, +zcat tries the compressed file names corresponding to the formats +supported. If a file fails to decompress, zcat continues copying the rest +of the files. If a file is specified as '-', data are read from standard input, decompressed if needed, and sent to standard output. Data read from standard input must be of the same type; all uncompressed or all in the -same compression format. +same compressed format. - If no files are specified, recursive searches examine the current -working directory, and nonrecursive searches read standard input. + If no files are specified, recursive searches examine the current working +directory, and nonrecursive searches read standard input. The format for running zcat is: zcat [OPTIONS] [FILES] -Exit status is 0 if no errors occurred, non-zero otherwise. +Exit status is 0 if no errors occurred, 1 otherwise. zcat supports the following options: @@ -217,8 +219,8 @@ Exit status is 0 if no errors occurred, non-zero otherwise. '-b' '--number-nonblank' - Number all nonblank output lines, starting with 1. The line count - is unlimited. + Number all nonblank output lines, starting with 1. The line count is + unlimited. '-e' Equivalent to '-vE'. @@ -229,16 +231,14 @@ Exit status is 0 if no errors occurred, non-zero otherwise. '-n' '--number' - Number all output lines, starting with 1. The line count is - unlimited. + Number all output lines, starting with 1. The line count is unlimited. '-O FORMAT' '--force-format=FORMAT' - Force the given compression format. Valid values for FORMAT are - 'bz2', 'gz', 'lz' and 'xz'. If this option is used, the files are - passed to the corresponding decompressor without verifying their - format, and the exact file name must be given. Other names won't - be tried. + Force the compressed format given. Valid values for FORMAT are 'bz2', + 'gz', 'lz', and 'xz'. If this option is used, the files are passed to + the corresponding decompressor without verifying their format, and the + exact file name must be given. Other names won't be tried. '-q' '--quiet' @@ -247,8 +247,8 @@ Exit status is 0 if no errors occurred, non-zero otherwise. '-r' '--recursive' For each directory operand, read and process all files in that - directory, recursively. Follow symbolic links in the command line, - but skip symlinks that are encountered recursively. + directory, recursively. Follow symbolic links given in the command + line, but skip symbolic links that are encountered recursively. '-R' '--dereference-recursive' @@ -282,28 +282,27 @@ File: zutils.info, Node: Zcmp, Next: Zdiff, Prev: Zcat, Up: Top 5 Zcmp ****** -zcmp compares two files ('-' means standard input), and if they differ, -tells the first byte and line number where they differ. Bytes and lines -are numbered starting with 1. If any given file is compressed, its -decompressed content is used. Compressed files are decompressed on the -fly; no temporary files are created. +zcmp compares two files and, if they differ, writes to standard output the +first byte and line number where they differ. Bytes and lines are numbered +starting with 1. A hyphen '-' used as a FILE argument means standard input. +If any file given is compressed, its decompressed content is used. +Compressed files are decompressed on the fly; no temporary files are +created. The format for running zcmp is: zcmp [OPTIONS] FILE1 [FILE2] -This compares FILE1 to FILE2. If FILE2 is omitted zcmp tries the +This compares FILE1 to FILE2. The standard input is used only if FILE1 or +FILE2 refers to standard input. If FILE2 is omitted zcmp tries the following: - 1. If FILE1 is compressed, compares its decompressed contents with - the corresponding uncompressed file (the name of FILE1 with the - extension removed). + - If FILE1 is compressed, compares its decompressed contents with the + corresponding uncompressed file (the name of FILE1 with the extension + removed). - 2. If FILE1 is uncompressed, compares it with the decompressed - contents of FILE1.[lz|bz2|gz|xz] (the first one that is found). - - 3. If no suitable file is found, compares FILE1 with data read from - standard input. + - If FILE1 is uncompressed, compares it with the decompressed contents + of FILE1.[lz|bz2|gz|xz] (the first one that is found). An exit status of 0 means no differences were found, 1 means some differences were found, and 2 means trouble. @@ -312,17 +311,16 @@ differences were found, and 2 means trouble. '-b' '--print-bytes' - Print the differing bytes. Print control bytes as a '^' followed by - a letter, and precede bytes larger than 127 with 'M-' (which stands - for "meta"). + Print the differing bytes. Print control bytes as a '^' followed by a + letter, and precede bytes larger than 127 with 'M-' (which stands for + "meta"). '-i SIZE' '--ignore-initial=SIZE' Ignore any differences in the first SIZE bytes of the input files. - Treat files with fewer than SIZE bytes as if they were empty. If - SIZE is in the form 'SIZE1:SIZE2', ignore the first SIZE1 bytes of - the first input file and the first SIZE2 bytes of the second input - file. + Treat files with fewer than SIZE bytes as if they were empty. If SIZE + is in the form 'SIZE1:SIZE2', ignore the first SIZE1 bytes of the + first input file and the first SIZE2 bytes of the second input file. '-l' '-v' @@ -337,20 +335,20 @@ differences were found, and 2 means trouble. '-O [FORMAT1][,FORMAT2]' '--force-format=[FORMAT1][,FORMAT2]' - Force the given compression formats. Any of FORMAT1 or FORMAT2 may - be omitted and the corresponding format will be automatically - detected. Valid values for FORMAT are 'bz2', 'gz', 'lz' and 'xz'. - If at least one format is specified with this option, the file is - passed to the corresponding decompressor without verifying its - format, and the exact file names of both FILE1 and FILE2 must be - given. Other names won't be tried. + Force the compressed formats given. Any of FORMAT1 or FORMAT2 may be + omitted and the corresponding format will be automatically detected. + Valid values for FORMAT are 'bz2', 'gz', 'lz', and 'xz'. If at least + one format is specified with this option, the file is passed to the + corresponding decompressor without verifying its format, and the exact + file names of both FILE1 and FILE2 must be given. Other names won't be + tried. '-q' '-s' '--quiet' '--silent' - Don't print anything; only return an exit status indicating - whether the files differ. + Don't print anything; only return an exit status indicating whether the + files differ. @@ -359,34 +357,33 @@ File: zutils.info, Node: Zdiff, Next: Zgrep, Prev: Zcmp, Up: Top 6 Zdiff ******* -zdiff compares two files ('-' means standard input), and if they -differ, shows the differences line by line. If any given file is -compressed, its decompressed content is used. zdiff is a front end to -the diff program and has the limitation that messages from diff refer to -temporary file names instead of those specified. +zdiff compares two files and, if they differ, writes to standard output the +differences line by line. A hyphen '-' used as a FILE argument means +standard input. If any file given is compressed, its decompressed content +is used. zdiff is a front end to the program diff and has the limitation +that messages from diff refer to temporary file names instead of those +specified. The format for running zdiff is: zdiff [OPTIONS] FILE1 [FILE2] -This compares FILE1 to FILE2. If FILE2 is omitted zdiff tries the +This compares FILE1 to FILE2. The standard input is used only if FILE1 or +FILE2 refers to standard input. If FILE2 is omitted zdiff tries the following: - 1. If FILE1 is compressed, compares its decompressed contents with - the corresponding uncompressed file (the name of FILE1 with the - extension removed). + - If FILE1 is compressed, compares its decompressed contents with the + corresponding uncompressed file (the name of FILE1 with the extension + removed). - 2. If FILE1 is uncompressed, compares it with the decompressed - contents of FILE1.[lz|bz2|gz|xz] (the first one that is found). - - 3. If no suitable file is found, compares FILE1 with data read from - standard input. + - If FILE1 is uncompressed, compares it with the decompressed contents + of FILE1.[lz|bz2|gz|xz] (the first one that is found). An exit status of 0 means no differences were found, 1 means some differences were found, and 2 means trouble. - zdiff supports the following options (some options only work if the -diff program used supports them): + zdiff supports the following options (some options only work if the diff +program used supports them): '-a' '--text' @@ -421,13 +418,13 @@ diff program used supports them): '-O [FORMAT1][,FORMAT2]' '--force-format=[FORMAT1][,FORMAT2]' - Force the given compression formats. Any of FORMAT1 or FORMAT2 may - be omitted and the corresponding format will be automatically - detected. Valid values for FORMAT are 'bz2', 'gz', 'lz' and 'xz'. - If at least one format is specified with this option, the file is - passed to the corresponding decompressor without verifying its - format, and the exact file names of both FILE1 and FILE2 must be - given. Other names won't be tried. + Force the compressed formats given. Any of FORMAT1 or FORMAT2 may be + omitted and the corresponding format will be automatically detected. + Valid values for FORMAT are 'bz2', 'gz', 'lz', and 'xz'. If at least + one format is specified with this option, the file is passed to the + corresponding decompressor without verifying its format, and the exact + file names of both FILE1 and FILE2 must be given. Other names won't be + tried. '-p' '--show-c-function' @@ -467,31 +464,29 @@ File: zutils.info, Node: Zgrep, Next: Ztest, Prev: Zdiff, Up: Top 7 Zgrep ******* -zgrep is a front end to the grep program that allows transparent search -on any combination of compressed and uncompressed files. If any given -file is compressed, its decompressed content is used. If a given file -does not exist, and its name does not end with one of the known -extensions, zgrep tries the compressed file names corresponding to the -formats supported. If a file fails to decompress, zgrep continues -searching the rest of the files. +zgrep is a front end to the program grep that allows transparent search on +any combination of compressed and uncompressed files. If any file given is +compressed, its decompressed content is used. If a file given does not +exist, and its name does not end with one of the known extensions, zgrep +tries the compressed file names corresponding to the formats supported. If +a file fails to decompress, zgrep continues searching the rest of the files. If a file is specified as '-', data are read from standard input, -decompressed if needed, and fed to grep. Data read from standard input -must be of the same type; all uncompressed or all in the same -compression format. +decompressed if needed, and fed to grep. Data read from standard input must +be of the same type; all uncompressed or all in the same compressed format. - If no files are specified, recursive searches examine the current -working directory, and nonrecursive searches read standard input. + If no files are specified, recursive searches examine the current working +directory, and nonrecursive searches read standard input. The format for running zgrep is: zgrep [OPTIONS] PATTERN [FILES] -An exit status of 0 means at least one match was found, 1 means no -matches were found, and 2 means trouble. +An exit status of 0 means at least one match was found, 1 means no matches +were found, and 2 means trouble. - zgrep supports the following options (some options only work if the -grep program used supports them): + zgrep supports the following options (some options only work if the grep +program used supports them): '-a' '--text' @@ -518,7 +513,7 @@ grep program used supports them): Print N lines of output context. '--color[=WHEN]' - Show matched strings in color. WHEN is 'never', 'always' or 'auto'. + Show matched strings in color. WHEN is 'never', 'always', or 'auto'. '-e PATTERN' '--regexp=PATTERN' @@ -531,9 +526,9 @@ grep program used supports them): '-f FILE' '--file=FILE' Obtain patterns from FILE, one per line. - When searching in several files at once, command substitution can - be used with '-e' to read FILE only once, for example if FILE is - not a regular file: 'zgrep -e "$(cat FILE)" file1.lz file2.gz' + When searching in several files at once, command substitution can be + used with '-e' to read FILE only once, for example if FILE is not a + regular file: 'zgrep -e "$(cat FILE)" file1.lz file2.gz' '-F' '--fixed-strings' @@ -541,8 +536,8 @@ grep program used supports them): '-h' '--no-filename' - Suppress the prefixing of file names on output when multiple files - are searched. + Suppress the prefixing of file names on output when multiple files are + searched. '-H' '--with-filename' @@ -577,22 +572,21 @@ grep program used supports them): '-O FORMAT' '--force-format=FORMAT' - Force the given compression format. Valid values for FORMAT are - 'bz2', 'gz', 'lz' and 'xz'. If this option is used, the files are - passed to the corresponding decompressor without verifying their - format, and the exact file name must be given. Other names won't - be tried. + Force the compressed format given. Valid values for FORMAT are 'bz2', + 'gz', 'lz', and 'xz'. If this option is used, the files are passed to + the corresponding decompressor without verifying their format, and the + exact file name must be given. Other names won't be tried. '-q' '--quiet' - Suppress all messages. Exit immediately with zero status if any - match is found, even if an error was detected. + Suppress all messages. Exit immediately with zero status if any match + is found, even if an error was detected. '-r' '--recursive' For each directory operand, read and process all files in that - directory, recursively. Follow symbolic links in the command line, - but skip symlinks that are encountered recursively. + directory, recursively. Follow symbolic links given in the command + line, but skip symbolic links that are encountered recursively. '-R' '--dereference-recursive' @@ -625,42 +619,43 @@ File: zutils.info, Node: Ztest, Next: Zupdate, Prev: Zgrep, Up: Top 8 Ztest ******* -ztest verifies the integrity of the specified compressed files. +ztest verifies the integrity of the compressed files specified. Uncompressed files are ignored. If a file is specified as '-', the integrity of compressed data read from standard input is verified. Data -read from standard input must be all in the same compression format. If -a file fails to decompress, ztest continues verifying the rest of the -files. +read from standard input must be all in the same compressed format. If a +file fails to decompress, does not exist, can't be opened, or is a +terminal, ztest continues verifying the rest of the files. A final +diagnostic is shown at verbosity level 1 or higher if any file fails the +test when testing multiple files. - If no files are specified, recursive searches examine the current -working directory, and nonrecursive searches read standard input. + If no files are specified, recursive searches examine the current working +directory, and nonrecursive searches read standard input. Note that error detection in the xz format is broken. First, some xz files lack integrity information. Second, not all xz decompressors can -verify the integrity of all xz files. Third, section 2.1.1.2 'Stream -Flags' of the xz format specification allows xz decompressors to -produce garbage output without issuing any warning. Therefore, xz files -can't always be verified as reliably as files in the other formats can. +verify the integrity of all xz files. Third, section 2.1.1.2 'Stream Flags' +of the xz format specification allows xz decompressors to produce garbage +output without issuing any warning. Therefore, xz files can't always be +verified as reliably as files in the other formats can. The format for running ztest is: ztest [OPTIONS] [FILES] -The exit status is 0 if all compressed files verify OK, 1 if -environmental problems (file not found, invalid flags, I/O errors, etc), -2 if any compressed file is corrupt or invalid. +The exit status is 0 if all compressed files verify OK, 1 if environmental +problems (file not found, invalid flags, I/O errors, etc), 2 if any +compressed file is corrupt or invalid. ztest supports the following options: '-O FORMAT' '--force-format=FORMAT' - Force the given compression format. Valid values for FORMAT are - 'bz2', 'gz', 'lz' and 'xz'. If this option is used, the files are - passed to the corresponding decompressor without verifying their - format, and any files in a format that the decompressor can't - understand will fail. For example, '--force-format=gz' can test - gzipped (.gz) and compress'd (.Z) files if the compressor used is - GNU gzip. + Force the compressed format given. Valid values for FORMAT are 'bz2', + 'gz', 'lz', and 'xz'. If this option is used, the files are passed to + the corresponding decompressor without verifying their format, and any + files in a format that the decompressor can't understand will fail. + For example, '--force-format=gz' can test gzipped (.gz) and compress'd + (.Z) files if the compressor used is GNU gzip. '-q' '--quiet' @@ -669,8 +664,8 @@ environmental problems (file not found, invalid flags, I/O errors, etc), '-r' '--recursive' For each directory operand, read and process all files in that - directory, recursively. Follow symbolic links in the command line, - but skip symlinks that are encountered recursively. + directory, recursively. Follow symbolic links given in the command + line, but skip symbolic links that are encountered recursively. '-R' '--dereference-recursive' @@ -689,68 +684,69 @@ File: zutils.info, Node: Zupdate, Next: Problems, Prev: Ztest, Up: Top 9 Zupdate ********* -zupdate recompresses files from bzip2, gzip, and xz formats to lzip -format. Each original is compared with the new file and then deleted. -Only regular files with standard file name extensions are recompressed, -other files are ignored. Compressed files are decompressed and then -recompressed on the fly; no temporary files are created. If an error -happens while recompressing a file, zupdate exits immediately without -recompressing the rest of the files. The lzip format is chosen as -destination because it is the most appropriate for long-term data -archiving. +zupdate recompresses files from bzip2, gzip, and xz formats to lzip format. +Each original is compared with the new file and then deleted. Only regular +files with standard file name extensions are recompressed, other files are +ignored. Compressed files are decompressed and then recompressed on the fly; +no temporary files are created. If an error happens while recompressing a +file, zupdate exits immediately without recompressing the rest of the files. +The lzip format is chosen as destination because it is the most appropriate +for long-term data archiving. - If no files are specified, recursive searches examine the current -working directory, and nonrecursive searches do nothing. + If no files are specified, recursive searches examine the current working +directory, and nonrecursive searches do nothing. If the lzip compressed version of a file already exists, the file is -skipped unless the '--force' option is given. In this case, if the -comparison with the existing lzip version fails, an error is returned -and the original file is not deleted. The operation of zupdate is meant -to be safe and not produce any data loss. Therefore, existing lzip -compressed files are never overwritten nor deleted. +skipped unless the option '--force' is given. In this case, if the +comparison with the existing lzip version fails, an error is returned and +the original file is not deleted. The operation of zupdate is meant to be +safe and not cause any data loss. Therefore, existing lzip compressed files +are never overwritten nor deleted. - Combining the '--force' and '--keep' options, as in -'zupdate -f -k *.gz', verifies that there are no differences between -each pair of files in a multiformat set of files. + Combining the options '--force' and '--keep', as in +'zupdate -f -k *.gz', verifies that there are no differences between each +pair of files in a multiformat set of files. The names of the original files must have one of the following -extensions: '.bz2', '.tbz', '.tbz2', '.gz', '.tgz', '.xz', '.txz'. The -files produced have the extensions '.lz' or '.tar.lz'. - - Recompressing a file is much like copying or moving it; therefore -zupdate preserves the access and modification dates, permissions, and, -when possible, ownership of the file just as 'cp -p' does. (If the user -ID or the group ID can't be duplicated, the file permission bits S_ISUID -and S_ISGID are cleared). +extensions: +'.bz2', '.gz', and '.xz' are recompressed to '.lz'. +'.tbz', '.tbz2', '.tgz', and '.txz' are recompressed to '.tlz'. +Keeping the combined extensions ('.tgz' -> '.tlz') may be useful when +recompressing Slackware packages, for example. + + Recompressing a file is much like copying or moving it; therefore zupdate +preserves the access and modification dates, permissions, and, when +possible, ownership of the file just as 'cp -p' does. (If the user ID or +the group ID can't be duplicated, the file permission bits S_ISUID and +S_ISGID are cleared). The format for running zupdate is: zupdate [OPTIONS] [FILES] -Exit status is 0 if all the compressed files were successfully -recompressed (if needed), compared and deleted (if requested). Non-zero -otherwise. +Exit status is 0 if all the compressed files were successfully recompressed +(if needed), compared, and deleted (if requested). Non-zero otherwise. zupdate supports the following options: '-f' '--force' - Don't skip a file for which a lzip compressed version already - exists. '--force' compares the content of the input file with the - content of the existing lzip file and deletes the input file if - both contents are identical. + Don't skip a file for which a lzip compressed version already exists. + '--force' compares the content of the input file with the content of + the existing lzip file and deletes the input file if both contents are + identical. '-k' '--keep' - Keep (don't delete) the input file after comparing it with the - lzip file. + Keep (don't delete) the input file after comparing it with the lzip + file. '-l' '--lzip-verbose' - Pass a '-v' option to the lzip compressor so that it shows the - compression ratio for each file processed. Using lzip 1.15 and - newer, a second '-l' shows the progress of compression. Use it - together with '-v' to see the name of the file. + Pass one option '-v' to the lzip compressor so that it shows the + compression ratio for each file processed. Using lzip 1.15 or newer, a + second '-l' shows the progress of compression. Use it together with + '-v' to see the name of the file. '-q' '--quiet' @@ -759,8 +755,8 @@ otherwise. '-r' '--recursive' For each directory operand, read and process all files in that - directory, recursively. Follow symbolic links in the command line, - but skip symlinks that are encountered recursively. + directory, recursively. Follow symbolic links given in the command + line, but skip symbolic links that are encountered recursively. '-R' '--dereference-recursive' @@ -769,12 +765,13 @@ otherwise. '-v' '--verbose' - Verbose mode. Show the files being processed. A second '-v' also - shows the files being ignored. + Verbose mode. Show the files being processed. A second '-v' also shows + the files being ignored. '-0 .. -9' - Set the compression level of lzip. By default zupdate passes '-9' - to lzip. + Set the compression level of lzip. By default zupdate passes '-9' to + lzip. Custom compression options can be passed to lzip with the option + '--lz'. For example '--lz='lzip -9 -s64MiB''. @@ -783,14 +780,14 @@ File: zutils.info, Node: Problems, Next: Concept index, Prev: Zupdate, Up: T 10 Reporting bugs ***************** -There are probably bugs in zutils. There are certainly errors and -omissions in this manual. If you report them, they will get fixed. If -you don't, no one will ever know about them and they will remain unfixed -for all eternity, if not longer. +There are probably bugs in zutils. There are certainly errors and omissions +in this manual. If you report them, they will get fixed. If you don't, no +one will ever know about them and they will remain unfixed for all +eternity, if not longer. If you find a bug in zutils, please send electronic mail to -<zutils-bug@nongnu.org>. Include the version number, which you can find -by running 'zupdate --version'. +<zutils-bug@nongnu.org>. Include the version number, which you can find by +running 'zupdate --version'. File: zutils.info, Node: Concept index, Prev: Problems, Up: Top @@ -801,34 +798,34 @@ Concept index * Menu: -* bugs: Problems. (line 6) -* common options: Common options. (line 6) -* getting help: Problems. (line 6) -* introduction: Introduction. (line 6) -* the zutilsrc file: The zutilsrc file. (line 6) -* zcat: Zcat. (line 6) -* zcmp: Zcmp. (line 6) -* zdiff: Zdiff. (line 6) -* zgrep: Zgrep. (line 6) -* ztest: Ztest. (line 6) -* zupdate: Zupdate. (line 6) +* bugs: Problems. (line 6) +* common options: Common options. (line 6) +* getting help: Problems. (line 6) +* introduction: Introduction. (line 6) +* the zutilsrc file: The zutilsrc file. (line 6) +* zcat: Zcat. (line 6) +* zcmp: Zcmp. (line 6) +* zdiff: Zdiff. (line 6) +* zgrep: Zgrep. (line 6) +* ztest: Ztest. (line 6) +* zupdate: Zupdate. (line 6) Tag Table: Node: Top222 -Node: Introduction1149 +Node: Introduction1148 Node: Common options3773 -Ref: compressor-requirements5596 -Node: The zutilsrc file5968 -Node: Zcat6893 -Node: Zcmp9445 -Node: Zdiff11904 -Node: Zgrep14608 -Node: Ztest18603 -Node: Zupdate20938 -Node: Problems24364 -Node: Concept index24898 +Ref: compressor-requirements5844 +Node: The zutilsrc file6216 +Node: Zcat7149 +Node: Zcmp9712 +Node: Zdiff12202 +Node: Zgrep14942 +Node: Ztest18944 +Node: Zupdate21451 +Node: Problems25123 +Node: Concept index25657 End Tag Table |