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diff --git a/gnu/usr.bin/gzip/gzip.1 b/gnu/usr.bin/gzip/gzip.1 deleted file mode 100644 index 795e47f..0000000 --- a/gnu/usr.bin/gzip/gzip.1 +++ /dev/null @@ -1,479 +0,0 @@ -.\" $FreeBSD$ -.\" -.PU -.TH GZIP 1 -.SH NAME -gzip, gunzip, zcat \- compress or expand files -.SH SYNOPSIS -.ll +8 -.B gzip -.RB [ " \-acdfhlLnNrtvV19 " ] -.RB [ \-S\ suffix ] -[ -.I "name \&..." -] -.ll -8 -.br -.B gunzip -.RB [ " \-acfhlLnNrtvV " ] -.RB [ \-S\ suffix ] -[ -.I "name \&..." -] -.br -.B zcat -.RB [ " \-fhLV " ] -[ -.I "name \&..." -] -.SH DESCRIPTION -.I Gzip -reduces the size of the named files using Lempel-Ziv coding (LZ77). -Whenever possible, -each file is replaced by one with the extension -.B "\&.gz," -while keeping the same ownership modes, access and modification times. -(The default extension is -.B "\-gz" -for VMS, -.B "z" -for MSDOS, OS/2 FAT, Windows NT FAT and Atari.) -If no files are specified, or if a file name is "-", the standard input is -compressed to the standard output. -.I Gzip -will only attempt to compress regular files. -In particular, it will ignore symbolic links. -.PP -If the compressed file name is too long for its file system, -.I gzip -truncates it. -.I Gzip -attempts to truncate only the parts of the file name longer than 3 characters. -(A part is delimited by dots.) If the name consists of small parts only, -the longest parts are truncated. For example, if file names are limited -to 14 characters, gzip.msdos.exe is compressed to gzi.msd.exe.gz. -Names are not truncated on systems which do not have a limit on file name -length. -.PP -By default, -.I gzip -keeps the original file name and timestamp in the compressed file. These -are used when decompressing the file with the -.B \-N -option. This is useful when the compressed file name was truncated or -when the time stamp was not preserved after a file transfer. -.PP -Compressed files can be restored to their original form using -.I gzip -d -or -.I gunzip -or -.I zcat. -If the original name saved in the compressed file is not suitable for its -file system, a new name is constructed from the original one to make it -legal. -.PP -.I gunzip -takes a list of files on its command line and replaces each -file whose name ends with .gz, -gz, .z, -z, _z or .Z -and which begins with the correct magic number with an uncompressed -file without the original extension. -.I gunzip -also recognizes the special extensions -.B "\&.tgz" -and -.B "\&.taz" -as shorthands for -.B "\&.tar.gz" -and -.B "\&.tar.Z" -respectively. -When compressing, -.I gzip -uses the -.B "\&.tgz" -extension if necessary instead of truncating a file with a -.B "\&.tar" -extension. -.PP -.I gunzip -can currently decompress files created by -.I gzip, zip, compress, compress -H -or -.I pack. -The detection of the input format is automatic. When using -the first two formats, -.I gunzip -checks a 32 bit CRC. For -.I pack, gunzip -checks the uncompressed length. The standard -.I compress -format was not designed to allow consistency checks. However -.I gunzip -is sometimes able to detect a bad .Z file. If you get an error -when uncompressing a .Z file, do not assume that the .Z file is -correct simply because the standard -.I uncompress -does not complain. This generally means that the standard -.I uncompress -does not check its input, and happily generates garbage output. -The SCO compress -H format (lzh compression method) does not include a CRC -but also allows some consistency checks. -.PP -Files created by -.I zip -can be uncompressed by gzip only if they have a single member compressed -with the 'deflation' method. This feature is only intended to help -conversion of tar.zip files to the tar.gz format. To extract zip files -with several members, use -.I unzip -instead of -.I gunzip. -.PP -.I zcat -is identical to -.I gunzip -.B \-c. -(On some systems, -.I zcat -may be installed as -.I gzcat -to preserve the original link to -.I compress.) -.I zcat -uncompresses either a list of files on the command line or its -standard input and writes the uncompressed data on standard output. -.I zcat -will uncompress files that have the correct magic number whether -they have a -.B "\&.gz" -suffix or not. -.PP -.I Gzip -uses the Lempel-Ziv algorithm used in -.I zip -and PKZIP. -The amount of compression obtained depends on the size of the -input and the distribution of common substrings. -Typically, text such as source code or English -is reduced by 60\-70%. -Compression is generally much better than that achieved by -LZW (as used in -.IR compress ), -Huffman coding (as used in -.IR pack ), -or adaptive Huffman coding -.RI ( compact ). -.PP -Compression is always performed, even if the compressed file is -slightly larger than the original. The worst case expansion is -a few bytes for the gzip file header, plus 5 bytes every 32K block, -or an expansion ratio of 0.015% for large files. Note that the actual -number of used disk blocks almost never increases. -.I gzip -preserves the mode, ownership and timestamps of files when compressing -or decompressing. - -.SH OPTIONS -.TP -.B \-a --ascii -ASCII text mode: convert end-of-lines using local conventions. This option -is supported only on some non-Unix systems. For MSDOS, CR LF is converted -to LF when compressing, and LF is converted to CR LF when decompressing. -.TP -.B \-c --stdout --to-stdout -Write output on standard output; keep original files unchanged. -If there are several input files, the output consists of a sequence of -independently compressed members. To obtain better compression, -concatenate all input files before compressing them. -.TP -.B \-d --decompress --uncompress -Decompress. -.TP -.B \-f --force -Force compression or decompression even if the file has multiple links -or the corresponding file already exists, or if the compressed data -is read from or written to a terminal. If the input data is not in -a format recognized by -.I gzip, -and if the option --stdout is also given, copy the input data without change -to the standard output: let -.I zcat -behave as -.I cat. -If -.B \-f -is not given, -and when not running in the background, -.I gzip -prompts to verify whether an existing file should be overwritten. -.TP -.B \-h --help -Display a help screen and quit. -.TP -.B \-l --list -For each compressed file, list the following fields: - - compressed size: size of the compressed file - uncompressed size: size of the uncompressed file - ratio: compression ratio (0.0% if unknown) - uncompressed_name: name of the uncompressed file - -The uncompressed size is given as -1 for files not in gzip format, -such as compressed .Z files. To get the uncompressed size for such a file, -you can use: - - zcat file.Z | wc -c - -In combination with the --verbose option, the following fields are also -displayed: - - method: compression method - crc: the 32-bit CRC of the uncompressed data - date & time: time stamp for the uncompressed file - -The compression methods currently supported are deflate, compress, lzh -(SCO compress -H) and pack. The crc is given as ffffffff for a file -not in gzip format. - -With --name, the uncompressed name, date and time are -those stored within the compress file if present. - -With --verbose, the size totals and compression ratio for all files -is also displayed, unless some sizes are unknown. With --quiet, -the title and totals lines are not displayed. -.TP -.B \-L --license -Display the -.I gzip -license and quit. -.TP -.B \-n --no-name -When compressing, do not save the original file name and time stamp by -default. (The original name is always saved if the name had to be -truncated.) When decompressing, do not restore the original file name -if present (remove only the -.I gzip -suffix from the compressed file name) and do not restore the original -time stamp if present (copy it from the compressed file). This option -is the default when decompressing. -.TP -.B \-N --name -When compressing, always save the original file name and time stamp; this -is the default. When decompressing, restore the original file name and -time stamp if present. This option is useful on systems which have -a limit on file name length or when the time stamp has been lost after -a file transfer. -.TP -.B \-q --quiet -Suppress all warnings. -.TP -.B \-r --recursive -Travel the directory structure recursively. If any of the file names -specified on the command line are directories, -.I gzip -will descend into the directory and compress all the files it finds there -(or decompress them in the case of -.I gunzip -). -.TP -.B \-S .suf --suffix .suf -Use suffix .suf instead of .gz. Any suffix can be given, but suffixes -other than .z and .gz should be avoided to avoid confusion when files -are transferred to other systems. A null suffix forces gunzip to try -decompression on all given files regardless of suffix, as in: - - gunzip -S "" * (*.* for MSDOS) - -Previous versions of gzip used -the .z suffix. This was changed to avoid a conflict with -.IR pack "(1)". -.TP -.B \-t --test -Test. Check the compressed file integrity. -.TP -.B \-v --verbose -Verbose. Display the name and percentage reduction for each file compressed -or decompressed. -.TP -.B \-V --version -Version. Display the version number and compilation options then quit. -.TP -.B \-# --fast --best -Regulate the speed of compression using the specified digit -.IR # , -where -.B \-1 -or -.B \-\-fast -indicates the fastest compression method (less compression) -and -.B \-9 -or -.B \-\-best -indicates the slowest compression method (best compression). -The default compression level is -.BR \-6 -(that is, biased towards high compression at expense of speed). -.SH "ADVANCED USAGE" -Multiple compressed files can be concatenated. In this case, -.I gunzip -will extract all members at once. For example: - - gzip -c file1 > foo.gz - gzip -c file2 >> foo.gz - -Then - gunzip -c foo - -is equivalent to - - cat file1 file2 - -In case of damage to one member of a .gz file, other members can -still be recovered (if the damaged member is removed). However, -you can get better compression by compressing all members at once: - - cat file1 file2 | gzip > foo.gz - -compresses better than - - gzip -c file1 file2 > foo.gz - -If you want to recompress concatenated files to get better compression, do: - - gzip -cd old.gz | gzip > new.gz - -If a compressed file consists of several members, the uncompressed -size and CRC reported by the --list option applies to the last member -only. If you need the uncompressed size for all members, you can use: - - gzip -cd file.gz | wc -c - -If you wish to create a single archive file with multiple members so -that members can later be extracted independently, use an archiver -such as tar or zip. GNU tar supports the -z option to invoke gzip -transparently. gzip is designed as a complement to tar, not as a -replacement. -.SH "ENVIRONMENT" -The environment variable -.B GZIP -can hold a set of default options for -.I gzip. -These options are interpreted first and can be overwritten by -explicit command line parameters. For example: - for sh: GZIP="-8v --name"; export GZIP - for csh: setenv GZIP "-8v --name" - for MSDOS: set GZIP=-8v --name - -On Vax/VMS, the name of the environment variable is GZIP_OPT, to -avoid a conflict with the symbol set for invocation of the program. -.SH "SEE ALSO" -znew(1), zcmp(1), zmore(1), zforce(1), gzexe(1), compress(1) -.SH "DIAGNOSTICS" -Exit status is normally 0; -if an error occurs, exit status is 1. If a warning occurs, exit status is 2. -.PP -Usage: gzip [-cdfhlLnNrtvV19] [-S suffix] [file ...] -.in +8 -Invalid options were specified on the command line. -.in -8 -.IR file : -not in gzip format -.in +8 -The file specified to -.I gunzip -has not been compressed. -.in -8 -.IR file: -Corrupt input. Use zcat to recover some data. -.in +8 -The compressed file has been damaged. The data up to the point of failure -can be recovered using -.in +8 -zcat file > recover -.in -16 -.IR file : -compressed with -.I xx -bits, can only handle -.I yy -bits -.in +8 -.I File -was compressed (using LZW) by a program that could deal with -more -.I bits -than the decompress code on this machine. -Recompress the file with gzip, which compresses better and uses -less memory. -.in -8 -.IR file : -already has .gz suffix -- no change -.in +8 -The file is assumed to be already compressed. -Rename the file and try again. -.in -8 -.I file -already exists; do you wish to overwrite (y or n)? -.in +8 -Respond "y" if you want the output file to be replaced; "n" if not. -.in -8 -gunzip: corrupt input -.in +8 -A SIGSEGV violation was detected which usually means that the input file has -been corrupted. -.in -8 -.I "xx.x%" -.in +8 -Percentage of the input saved by compression. -(Relevant only for -.BR \-v -and -.BR \-l \.) -.in -8 --- not a regular file or directory: ignored -.in +8 -When the input file is not a regular file or directory, -(e.g. a symbolic link, socket, FIFO, device file), it is -left unaltered. -.in -8 --- has -.I xx -other links: unchanged -.in +8 -The input file has links; it is left unchanged. See -.IR ln "(1)" -for more information. Use the -.B \-f -flag to force compression of multiply-linked files. -.in -8 -.SH CAVEATS -When writing compressed data to a tape, it is generally necessary to -pad the output with zeroes up to a block boundary. When the data is -read and the whole block is passed to -.I gunzip -for decompression, -.I gunzip -detects that there is extra trailing garbage after the compressed data -and emits a warning by default. You have to use the --quiet option to -suppress the warning. This option can be set in the -.B GZIP -environment variable as in: - for sh: GZIP="-q" tar -xfz --block-compress /dev/rst0 - for csh: (setenv GZIP -q; tar -xfz --block-compr /dev/rst0 - -In the above example, gzip is invoked implicitly by the -z option of -GNU tar. Make sure that the same block size (-b option of tar) is used -for reading and writing compressed data on tapes. (This example -assumes you are using the GNU version of tar.) -.SH BUGS -The --list option reports incorrect sizes if they exceed 2 gigabytes. -The --list option reports sizes as -1 and crc as ffffffff if the -compressed file is on a non seekable media. - -In some rare cases, the --best option gives worse compression than -the default compression level (-6). On some highly redundant files, -.I compress -compresses better than -.I gzip. |
