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diff --git a/doc/zutils.texi b/doc/zutils.texi new file mode 100644 index 0000000..c494185 --- /dev/null +++ b/doc/zutils.texi @@ -0,0 +1,882 @@ +\input texinfo @c -*-texinfo-*- +@c %**start of header +@setfilename zutils.info +@documentencoding ISO-8859-15 +@settitle Zutils Manual +@finalout +@c %**end of header + +@set UPDATED 5 January 2021 +@set VERSION 1.10 + +@dircategory Data Compression +@direntry +* Zutils: (zutils). Utilities dealing with compressed files +@end direntry + + +@ifnothtml +@titlepage +@title Zutils +@subtitle Utilities dealing with compressed files +@subtitle for Zutils version @value{VERSION}, @value{UPDATED} +@author by Antonio Diaz Diaz + +@page +@vskip 0pt plus 1filll +@end titlepage + +@contents +@end ifnothtml + +@ifnottex +@node Top +@top + +This manual is for Zutils (version @value{VERSION}, @value{UPDATED}). + +@menu +* Introduction:: Purpose and features of zutils +* Common options:: Options common to all utilities +* The zutilsrc file:: The zutils configuration file +* Zcat:: Concatenating compressed files +* Zcmp:: Comparing compressed files byte by byte +* Zdiff:: Comparing compressed files line by line +* Zgrep:: Searching inside compressed files +* Ztest:: Testing the integrity of compressed files +* Zupdate:: Recompressing files to lzip format +* Problems:: Reporting bugs +* Concept index:: Index of concepts +@end menu + +@sp 1 +Copyright @copyright{} 2009-2021 Antonio Diaz Diaz. + +This manual is free documentation: you have unlimited permission to copy, +distribute, and modify it. +@end ifnottex + + +@node Introduction +@chapter Introduction +@cindex introduction + +@uref{http://www.nongnu.org/zutils/zutils.html,,Zutils} +is a collection of utilities able to process any combination of +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 option @samp{--recursive} is very efficient in +those utilities supporting it. + +@noindent +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. + +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. +@xref{compressor-requirements}. + +FORMAT NOTE 1: The option @samp{--format} allows the processing of a subset +of formats in recursive mode and when trying compressed file names: +@w{@samp{zgrep foo -r --format=bz2,lz somedir somefile.tar}}. + +FORMAT NOTE 2: If the option @samp{--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: +@w{@samp{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. + +@sp 1 +Numbers given as arguments to options (positions, sizes) may be followed +by a multiplier and an optional @samp{B} for "byte". + +Table of SI and binary prefixes (unit multipliers): + +@multitable {Prefix} {kilobyte (10^3 = 1000)} {|} {Prefix} {kibibyte (2^10 = 1024)} +@item Prefix @tab Value @tab | @tab Prefix @tab Value +@item k @tab kilobyte (10^3 = 1000) @tab | @tab Ki @tab kibibyte (2^10 = 1024) +@item M @tab megabyte (10^6) @tab | @tab Mi @tab mebibyte (2^20) +@item G @tab gigabyte (10^9) @tab | @tab Gi @tab gibibyte (2^30) +@item T @tab terabyte (10^12) @tab | @tab Ti @tab tebibyte (2^40) +@item P @tab petabyte (10^15) @tab | @tab Pi @tab pebibyte (2^50) +@item E @tab exabyte (10^18) @tab | @tab Ei @tab exbibyte (2^60) +@item Z @tab zettabyte (10^21) @tab | @tab Zi @tab zebibyte (2^70) +@item Y @tab yottabyte (10^24) @tab | @tab Yi @tab yobibyte (2^80) +@end multitable + + +@node Common options +@chapter Common options +@cindex common options + +The following +@uref{http://www.nongnu.org/arg-parser/manual/arg_parser_manual.html#Argument-syntax,,options}: +are available in all the utilities. Rather than writing identical +descriptions for each of the programs, they are described here. +@ifnothtml +@xref{Argument syntax,,,arg_parser}. +@end ifnothtml + +@table @code +@item -h +@itemx --help +Print an informative help message describing the options and exit. zgrep +only supports the @samp{--help} form of this option. + +@item -V +@itemx --version +Print the version number on the standard output and exit. +This version number should be included in all bug reports. + +@item -M @var{format_list} +@itemx --format=@var{format_list} +Process only the formats listed in the comma-separated +@var{format_list}. Valid formats are @samp{bz2}, @samp{gz}, @samp{lz}, +@samp{xz}, and @samp{un} for @samp{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 @var{format_list} enables file names with the following +extensions: + +@multitable {bz2} {enables} {any other file name} +@item bz2 @tab enables @tab .bz2 .tbz .tbz2 +@item gz @tab enables @tab .gz .tgz +@item lz @tab enables @tab .lz .tlz +@item xz @tab enables @tab .xz .txz +@item un @tab enables @tab any other file name +@end multitable + +@item -N +@itemx --no-rcfile +Don't read the runtime configuration file @samp{zutilsrc}. + +@item --bz2=@var{command} +@itemx --gz=@var{command} +@itemx --lz=@var{command} +@itemx --xz=@var{command} +Set program to be used as (de)compressor for the corresponding format. +@var{command} may include arguments. For example +@w{@samp{--lz='plzip --threads=2'}}. The program set with @samp{--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 @samp{-}. These +options override the values set in @file{zutilsrc}. The compression program +used must meet three requirements: + +@anchor{compressor-requirements} +@enumerate +@item +When called with the option @samp{-d}, it must read compressed data from +the standard input and produce decompressed data on the standard output. +@item +If the option @samp{-q} is passed to zutils, the compression program must +also accept it. +@item +It must return 0 if no errors occurred, and a non-zero value otherwise. +@end enumerate + +@end table + + +@node The zutilsrc file +@chapter The zutils configuration file 'zutilsrc' +@cindex zutilsrc + +@file{zutilsrc} is the runtime configuration file for zutils. In it you +may define the compressor name and options to be used for each format. +@file{zutilsrc} 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 @file{zutilsrc}. + +You may copy the system @file{zutilsrc} file @file{$@{sysconfdir@}/zutilsrc} +to @file{$HOME/.zutilsrc} and customize these options as you like. The file +syntax is fairly obvious (and there are further instructions in it): + +@enumerate +@item +Any line beginning with @samp{#} is a comment line. +@item +Each non-comment line defines the command to be used for the corresponding +format, with the syntax: +@example +<format> = <compressor> [options] +@end example +where <format> is one of @samp{bz2}, @samp{gz}, @samp{lz}, or @samp{xz}. +@end enumerate + + +@node Zcat +@chapter Zcat +@cindex zcat + +zcat copies each @var{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 @samp{-}, 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 compressed format. + +If no files are specified, recursive searches examine the current working +directory, and nonrecursive searches read standard input. + +The format for running zcat is: + +@example +zcat [@var{options}] [@var{files}] +@end example + +@noindent +Exit status is 0 if no errors occurred, 1 otherwise. + +zcat supports the following options: + +@table @code +@item -A +@itemx --show-all +Equivalent to @samp{-vET}. + +@item -b +@itemx --number-nonblank +Number all nonblank output lines, starting with 1. The line count is +unlimited. + +@item -e +Equivalent to @samp{-vE}. + +@item -E +@itemx --show-ends +Print a @samp{$} after the end of each line. + +@item -n +@itemx --number +Number all output lines, starting with 1. The line count is unlimited. + +@item -O @var{format} +@itemx --force-format=@var{format} +Force the compressed format given. Valid values for @var{format} are +@samp{bz2}, @samp{gz}, @samp{lz}, and @samp{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. + +@item -q +@itemx --quiet +Quiet operation. Suppress all messages. + +@item -r +@itemx --recursive +For each directory operand, read and process all files in that directory, +recursively. Follow symbolic links given in the command line, but skip +symbolic links that are encountered recursively. + +@item -R +@itemx --dereference-recursive +For each directory operand, read and process all files in that directory, +recursively, following all symbolic links. + +@item -s +@itemx --squeeze-blank +Replace multiple adjacent blank lines with a single blank line. + +@item -t +Equivalent to @samp{-vT}. + +@item -T +@itemx --show-tabs +Print TAB characters as @samp{^I}. + +@item -v +@itemx --show-nonprinting +Print control characters except for LF (newline) and TAB using @samp{^} +notation and precede characters larger than 127 with @samp{M-} (which +stands for "meta"). + +@item --verbose +Verbose mode. Show error messages. + +@end table + + +@node Zcmp +@chapter Zcmp +@cindex zcmp + +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 @samp{-} used as a @var{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: + +@example +zcmp [@var{options}] @var{file1} [@var{file2}] +@end example + +@noindent +This compares @var{file1} to @var{file2}. The standard input is used only if +@var{file1} or @var{file2} refers to standard input. If @var{file2} is +omitted zcmp tries the following: + +@itemize - +@item +If @var{file1} is compressed, compares its decompressed contents with +the corresponding uncompressed file (the name of @var{file1} with the +extension removed). +@item +If @var{file1} is uncompressed, compares it with the decompressed +contents of @var{file1}.[lz|bz2|gz|xz] (the first one that is found). +@end itemize + +@noindent +An exit status of 0 means no differences were found, 1 means some +differences were found, and 2 means trouble. + +zcmp supports the following options: + +@table @code +@item -b +@itemx --print-bytes +Print the differing bytes. Print control bytes as a @samp{^} followed by +a letter, and precede bytes larger than 127 with @samp{M-} (which stands +for "meta"). + +@item -i @var{size} +@itemx --ignore-initial=@var{size} +Ignore any differences in the first @var{size} bytes of the input files. +Treat files with fewer than @var{size} bytes as if they were empty. If +@var{size} is in the form @samp{@var{size1}:@var{size2}}, ignore the +first @var{size1} bytes of the first input file and the first +@var{size2} bytes of the second input file. + +@item -l +@itemx -v +@itemx --list +@itemx --verbose +Print the byte numbers (in decimal) and values (in octal) of all +differing bytes. + +@item -n @var{count} +@itemx --bytes=@var{count} +Compare at most @var{count} input bytes. + +@item -O [@var{format1}][,@var{format2}] +@itemx --force-format=[@var{format1}][,@var{format2}] +Force the compressed formats given. Any of @var{format1} or +@var{format2} may be omitted and the corresponding format will be +automatically detected. Valid values for @var{format} are @samp{bz2}, +@samp{gz}, @samp{lz}, and @samp{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 +@var{file1} and @var{file2} must be given. Other names won't be tried. + +@item -q +@itemx -s +@itemx --quiet +@itemx --silent +Don't print anything; only return an exit status indicating whether the +files differ. + +@end table + + +@node Zdiff +@chapter Zdiff +@cindex zdiff + +zdiff compares two files and, if they differ, writes to standard output the +differences line by line. A hyphen @samp{-} used as a @var{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: + +@example +zdiff [@var{options}] @var{file1} [@var{file2}] +@end example + +@noindent +This compares @var{file1} to @var{file2}. The standard input is used only if +@var{file1} or @var{file2} refers to standard input. If @var{file2} is +omitted zdiff tries the following: + +@itemize - +@item +If @var{file1} is compressed, compares its decompressed contents with +the corresponding uncompressed file (the name of @var{file1} with the +extension removed). +@item +If @var{file1} is uncompressed, compares it with the decompressed +contents of @var{file1}.[lz|bz2|gz|xz] (the first one that is found). +@end itemize + +@noindent +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): + +@table @code +@item -a +@itemx --text +Treat all files as text. + +@item -b +@itemx --ignore-space-change +Ignore changes in the amount of white space. + +@item -B +@itemx --ignore-blank-lines +Ignore changes whose lines are all blank. + +@itemx -c +Use the context output format. + +@item -C @var{n} +@itemx --context=@var{n} +Same as -c but use @var{n} lines of context. + +@item -d +@itemx --minimal +Try hard to find a smaller set of changes. + +@item -E +@itemx --ignore-tab-expansion +Ignore changes due to tab expansion. + +@item -i +@itemx --ignore-case +Ignore case differences in file contents. + +@item -O [@var{format1}][,@var{format2}] +@itemx --force-format=[@var{format1}][,@var{format2}] +Force the compressed formats given. Any of @var{format1} or +@var{format2} may be omitted and the corresponding format will be +automatically detected. Valid values for @var{format} are @samp{bz2}, +@samp{gz}, @samp{lz}, and @samp{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 +@var{file1} and @var{file2} must be given. Other names won't be tried. + +@item -p +@itemx --show-c-function +Show which C function each change is in. + +@item -q +@itemx --brief +Output only whether files differ. + +@item -s +@itemx --report-identical-files +Report when two files are identical. + +@item -t +@itemx --expand-tabs +Expand tabs to spaces in output. + +@item -T +@itemx --initial-tab +Make tabs line up by prepending a tab. + +@item -u +Use the unified output format. + +@item -U @var{n} +@itemx --unified=@var{n} +Same as -u but use @var{n} lines of context. + +@item -w +@itemx --ignore-all-space +Ignore all white space. + +@end table + + +@node Zgrep +@chapter Zgrep +@cindex zgrep + +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 @samp{-}, 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 +compressed format. + +If no files are specified, recursive searches examine the current working +directory, and nonrecursive searches read standard input. + +The format for running zgrep is: + +@example +zgrep [@var{options}] @var{pattern} [@var{files}] +@end example + +@noindent +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): + +@table @code +@item -a +@itemx --text +Treat all files as text. + +@item -A @var{n} +@itemx --after-context=@var{n} +Print @var{n} lines of trailing context. + +@item -b +@itemx --byte-offset +Print the byte offset of each line. + +@item -B @var{n} +@itemx --before-context=@var{n} +Print @var{n} lines of leading context. + +@item -c +@itemx --count +Only print a count of matching lines per file. + +@item -C @var{n} +@itemx --context=@var{n} +Print @var{n} lines of output context. + +@item --color[=@var{when}] +Show matched strings in color. @var{when} is @samp{never}, @samp{always}, +or @samp{auto}. + +@item -e @var{pattern} +@itemx --regexp=@var{pattern} +Use @var{pattern} as the pattern to match. + +@item -E +@itemx --extended-regexp +Treat @var{pattern} as an extended regular expression. + +@item -f @var{file} +@itemx --file=@var{file} +Obtain patterns from @var{file}, one per line.@* +When searching in several files at once, command substitution can be +used with @samp{-e} to read @var{file} only once, for example if +@var{file} is not a regular file: +@w{@samp{zgrep -e "$(cat @var{file})" file1.lz file2.gz}} + +@item -F +@itemx --fixed-strings +Treat @var{pattern} as a set of newline-separated strings. + +@item -h +@itemx --no-filename +Suppress the prefixing of file names on output when multiple files are +searched. + +@item -H +@itemx --with-filename +Print the file name for each match. + +@item -i +@itemx --ignore-case +Ignore case distinctions. + +@item -I +Ignore binary files. + +@item -l +@itemx --files-with-matches +Only print names of files containing at least one match. + +@item -L +@itemx --files-without-match +Only print names of files not containing any matches.@* +Note: option -L fails (prints wrong results, returns wrong status, and even +hangs) when using GNU grep versions 3.2 to 3.4 inclusive because of a wrong +change in the exit status of grep, which was reverted in GNU grep 3.5. + +@item -m @var{n} +@itemx --max-count=@var{n} +Stop after @var{n} matches. + +@item -n +@itemx --line-number +Prefix each matched line with its line number in the input file. + +@item -o +@itemx --only-matching +Show only the part of matching lines that actually matches @var{pattern}. + +@item -O @var{format} +@itemx --force-format=@var{format} +Force the compressed format given. Valid values for @var{format} are +@samp{bz2}, @samp{gz}, @samp{lz}, and @samp{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. + +@item -q +@itemx --quiet +Suppress all messages. Exit immediately with zero status if any match is +found, even if an error was detected. + +@item -r +@itemx --recursive +For each directory operand, read and process all files in that directory, +recursively. Follow symbolic links given in the command line, but skip +symbolic links that are encountered recursively. + +@item -R +@itemx --dereference-recursive +For each directory operand, read and process all files in that directory, +recursively, following all symbolic links. + +@item -s +@itemx --no-messages +Suppress error messages about nonexistent or unreadable files. + +@item -v +@itemx --invert-match +Select non-matching lines. + +@item --verbose +Verbose mode. Show error messages. + +@item -w +@itemx --word-regexp +Match only whole words. + +@item -x +@itemx --line-regexp +Match only whole lines. + +@end table + + +@node Ztest +@chapter Ztest +@cindex ztest + +ztest verifies the integrity of the compressed files specified. +Uncompressed files are ignored. If a file is specified as @samp{-}, the +integrity of compressed data read from standard input is verified. Data +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. + +Note that error detection in the xz format is broken. First, some xz +files lack integrity information. Second, not all xz decompressors can +@uref{http://www.nongnu.org/lzip/xz_inadequate.html#fragmented,,verify the integrity} +of all xz files. Third, section 2.1.1.2 'Stream Flags' of the +@uref{http://tukaani.org/xz/xz-file-format.txt,,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. +@c We can only hope that xz is soon abandoned. + +The format for running ztest is: + +@example +ztest [@var{options}] [@var{files}] +@end example + +@noindent +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: + +@table @code +@item -O @var{format} +@itemx --force-format=@var{format} +Force the compressed format given. Valid values for @var{format} are +@samp{bz2}, @samp{gz}, @samp{lz}, and @samp{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, @samp{--force-format=gz} can test gzipped (.gz) and +compress'd (.Z) files if the compressor used is GNU gzip. + +@item -q +@itemx --quiet +Quiet operation. Suppress all messages. + +@item -r +@itemx --recursive +For each directory operand, read and process all files in that directory, +recursively. Follow symbolic links given in the command line, but skip +symbolic links that are encountered recursively. + +@item -R +@itemx --dereference-recursive +For each directory operand, read and process all files in that directory, +recursively, following all symbolic links. + +@item -v +@itemx --verbose +Verbose mode. Show the verify status for each file processed.@* +Further -v's increase the verbosity level. + +@end table + + +@node Zupdate +@chapter Zupdate +@cindex 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. + +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 option @samp{--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 options @samp{--force} and @samp{--keep}, as in +@w{@samp{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:@* +@samp{.bz2}, @samp{.gz}, or @samp{.xz}, which are recompressed to +@samp{.lz};@* +@samp{.tbz}, @samp{.tbz2}, @samp{.tgz}, or @samp{.txz}, which are +recompressed to @samp{.tlz}.@* +Keeping the combined extensions (@samp{.tgz} --> @samp{.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 @samp{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: + +@example +zupdate [@var{options}] [@var{files}] +@end example + +@noindent +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: + +@table @code +@item -f +@itemx --force +Don't skip a file for which a lzip compressed version already exists. +@samp{--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. + +@item -k +@itemx --keep +Keep (don't delete) the input file after comparing it with the lzip file. + +@item -l +@itemx --lzip-verbose +Pass one option @samp{-v} to the lzip compressor so that it shows the +compression ratio for each file processed. Using lzip 1.15 or newer, a +second @samp{-l} shows the progress of compression. Use it together with +@samp{-v} to see the name of the file. + +@item -q +@itemx --quiet +Quiet operation. Suppress all messages. + +@item -r +@itemx --recursive +For each directory operand, read and process all files in that directory, +recursively. Follow symbolic links given in the command line, but skip +symbolic links that are encountered recursively. + +@item -R +@itemx --dereference-recursive +For each directory operand, read and process all files in that directory, +recursively, following all symbolic links. + +@item -v +@itemx --verbose +Verbose mode. Show the files being processed. A second @samp{-v} also +shows the files being ignored. + +@item -0 .. -9 +Set the compression level of lzip. By default zupdate passes @samp{-9} to +lzip. Custom compression options can be passed to lzip with the option +@samp{--lz}. For example @w{@samp{--lz='lzip -9 -s64MiB'}}. + +@end table + + +@node Problems +@chapter Reporting bugs +@cindex bugs +@cindex getting help + +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 +@email{zutils-bug@@nongnu.org}. Include the version number, which you can +find by running @w{@samp{zupdate --version}}. + + +@node Concept index +@unnumbered Concept index + +@printindex cp + +@bye |