Files created by 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 unzip instead of gunzip.
+ tar.zip files to the tar.gz format. To extract a zip file
+ with a single member, use a command like gunzip <foo.zip or
+ gunzip -S .zip foo.zip. To extract zip files with several
+ members, use unzip instead of gunzip.
zcat is identical to gunzip -c. (On some systems, zcat may
be installed as gzcat to preserve the original link to com-
almost never increases. gzip preserves the mode, ownership
and timestamps of files when compressing or decompressing.
+ The gzip file format is specified in P. Deutsch, GZIP file
+ format specification version 4.3, <ftp://ftp.isi.edu/in-
+ notes/rfc1952.txt>, Internet RFC 1952 (May 1996). The zip
+ deflation format is specified in P. Deutsch, DEFLATE Com-
+ pressed Data Format Specification version 1.3,
+ <ftp://ftp.isi.edu/in-notes/rfc1951.txt>, Internet RFC 1951
+ (May 1996).
+
+SunOS 5.8 Last change: local 2
+
+User Commands GZIP(1)
+
OPTIONS
-a --ascii
Ascii text mode: convert end-of-lines using local con-
pressing.
-c --stdout --to-stdout
-
-SunOS 5.8 Last change: local 2
-
-User Commands GZIP(1)
-
Write output on standard output; keep original files
unchanged. If there are several input files, the out-
put consists of a sequence of independently compressed
method: compression method
crc: the 32-bit CRC of the uncompressed data
+
+SunOS 5.8 Last change: local 3
+
+User Commands GZIP(1)
+
date & time: time stamp for the uncompressed file
The compression methods currently supported are
With --name, the uncompressed name, date and time are
those stored within the compress file if present.
-SunOS 5.8 Last change: local 3
-
-User Commands GZIP(1)
-
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
decompression on all given files regardless of suffix,
as in:
+SunOS 5.8 Last change: local 4
+
+User Commands GZIP(1)
+
gunzip -S "" * (*.* for MSDOS)
Previous versions of gzip used the .z suffix. This was
-t --test
Test. Check the compressed file integrity.
-SunOS 5.8 Last change: local 4
-
-User Commands GZIP(1)
-
-v --verbose
Verbose. Display the name and percentage reduction for
each file compressed or decompressed.
If you want to recompress concatenated files to get better
compression, do:
+SunOS 5.8 Last change: local 5
+
+User Commands GZIP(1)
+
gzip -cd old.gz | gzip > new.gz
If a compressed file consists of several members, the uncom-
to the last member only. If you need the uncompressed size
for all members, you can use:
-SunOS 5.8 Last change: local 5
-
-User Commands GZIP(1)
-
gzip -cd file.gz | wc -c
If you wish to create a single archive file with multiple
file: Corrupt input. Use zcat to recover some data.
The compressed file has been damaged. The data up to
+
+SunOS 5.8 Last change: local 6
+
+User Commands GZIP(1)
+
the point of failure can be recovered using
zcat file > recover
file: compressed with xx bits, can only handle yy bits
File was compressed (using LZW) by a program that could
deal with more bits than the decompress code on this
-
-SunOS 5.8 Last change: local 6
-
-User Commands GZIP(1)
-
machine. Recompress the file with gzip, which com-
presses better and uses less memory.
data on tapes. (This example assumes you are using the GNU
version of tar.)
+SunOS 5.8 Last change: local 7
+
+User Commands GZIP(1)
+
BUGS
The gzip format represents the the input size modulo 2^32,
so the --list option reports incorrect uncompressed sizes
and compression ratios for uncompressed files 4 GB and
larger. To work around this problem, you can use the fol-
lowing command to discover a large uncompressed file's true
-
-SunOS 5.8 Last change: local 7
-
-User Commands GZIP(1)
-
size:
zcat file.gz | wc -c
redundant files, compress compresses better than gzip.
COPYRIGHT NOTICE
- Copyright (C) 1998, 1999, 2001 Free Software Foundation,
- Inc.
+ Copyright (C) 1998, 1999, 2001, 2002 Free Software Founda-
+ tion, Inc.
Copyright (C) 1992, 1993 Jean-loup Gailly
Permission is granted to make and distribute verbatim copies
projects / gzip / blobdiff