gzip.1 (3072B)
1 .TH GZIP 1 2 .SH NAME 3 gzip, gunzip, bzip2, bunzip2, zip, unzip, \- compress and expand data 4 .SH SYNOPSIS 5 .B gzip 6 .RB [ -cvD [ 1-9 ]] 7 .RI [ file 8 .BR ... ] 9 .PP 10 .B gunzip 11 .RB [ -ctTvD ] 12 .RI [ file 13 .BR ... ] 14 .PP 15 .B bzip2 16 .RB [ -cvD [ 1-9 ]] 17 .RI [ file 18 .BR ... ] 19 .PP 20 .B bunzip2 21 .RB [ -cvD ] 22 .RI [ file 23 .BR ... ] 24 .PP 25 .B zip 26 .RB [ -vD [ 1-9 ]] 27 .RB [ -f 28 .IR zipfile ] 29 .I file 30 .RB [ ... ] 31 .PP 32 .B unzip 33 .RB [ -cistTvD ] 34 .RB [ -f 35 .IR zipfile ] 36 .IR [ file 37 .BR ... ] 38 .SH DESCRIPTION 39 .PP 40 .I Gzip 41 encodes files with a hybrid Lempel-Ziv 1977 and Huffman compression algorithm 42 known as 43 .BR deflate . 44 Most of the time, the resulting file is smaller, 45 and will never be much bigger. 46 Output files are named by taking the last path element of each file argument 47 and appending 48 .BR .gz ; 49 if the resulting name ends with 50 .BR .tar.gz , 51 it is converted to 52 .B .tgz 53 instead. 54 .I Gunzip 55 reverses the process. 56 Its output files are named by taking the last path element of each file argument, 57 converting 58 .B .tgz 59 to 60 .BR .tar.gz , 61 and stripping any 62 .BR .gz ; 63 the resulting name must be different from the original name. 64 .PP 65 .I Bzip2 66 and 67 .I bunzip2 68 are similar in interface to 69 .I gzip 70 and 71 .IR gunzip , 72 but use a modified Burrows-Wheeler block sorting 73 compression algorithm. 74 The default suffix for output files is 75 .BR .bz2 , 76 with 77 .B .tar.bz2 78 becoming 79 .BR .tbz . 80 .I Bunzip2 81 recognizes the extension 82 .B .tbz2 83 as a synonym for 84 .BR .tbz . 85 .PP 86 .I Zip 87 encodes the named files and places the results into the archive 88 .IR zipfile , 89 or the standard output if no file is given. 90 .I Unzip 91 extracts files from an archive created by 92 .IR zip . 93 If no files are named as arguments, all of files in the archive are extracted. 94 A directory's name implies all recursively contained files and subdirectories. 95 .PP 96 None of these programs removes the original files. 97 If the process fails, the faulty output files are removed. 98 .PP 99 The options are: 100 .TP 1i 101 .B -c 102 Write to standard output rather than creating an output file. 103 .TP 104 .B -i 105 Convert all archive file names to lower case. 106 .TP 107 .B -s 108 Streaming mode. Looks at the file data adjacent to each compressed file 109 rather than seeking in the central file directory. 110 This is the mode used by 111 .I unzip 112 if no 113 .I zipfile 114 is specified. 115 If 116 .B -s 117 is given, 118 .B -T 119 is ignored. 120 .TP 121 .B -t 122 List matching files in the archive rather than extracting them. 123 .TP 124 .B -T 125 Set the output time to that specified in the archive. 126 .TP 127 .BR -1 " .. " -9 128 Sets the compression level. 129 .B -1 130 is tuned for speed, 131 .B -9 132 for minimal output size. 133 The best compromise is 134 .BR -6 , 135 the default. 136 .TP 137 .B -v 138 Produce more descriptive output. 139 With 140 .BR -t , 141 adds the uncompressed size in bytes and the modification time to the output. 142 Without 143 .BR -t , 144 prints the names of files on standard error as they are compressed or decompressed. 145 .TP 146 .B -D 147 Produce debugging output. 148 .SH SOURCE 149 .B \*9/src/cmd/gzip 150 .br 151 .B \*9/src/cmd/bzip2 152 .SH SEE ALSO 153 .MR tar (1) , 154 .MR compress (1) 155 .SH BUGS 156 .I Unzip 157 can only extract files which are uncompressed or compressed 158 with the 159 .B deflate 160 compression scheme. Recent zip files fall into this category.