Gzip and Bzip2 on Linux
阿新 • • 發佈：2018-12-23
gzip 可以說是應用度最廣的壓縮命令了！目前 gzip 可以解開 compress, zip 與 gzip 等軟體所壓縮的檔案。
gzip help
[[email protected] Workspace]# gzip -h
Usage: gzip [OPTION]... [FILE]...
Compress or uncompress FILEs (by default, compress FILES in-place).
Mandatory arguments to long options are mandatory for short options too.
-c, --stdout write on standard output, keep original files unchanged
-d, --decompress decompress
-f, --force force overwrite of output file and compress links
-h, --help give this help
-l, --list list compressed file contents
-L, --license display software license
-n, --no-name do not save or restore the original name and time stamp
-N, --name save or restore the original name and time stamp
-q, --quiet suppress all warnings
-r, --recursive operate recursively on directories
-S, --suffix=SUF use suffix SUF on compressed files
-t, --test test compressed file integrity
-v, --verbose verbose mode
-V, --version display version number
-1, --fast compress faster
-9, --best compress better
--rsyncable Make rsync-friendly archive
With no FILE, or when FILE is -, read standard input.
Report bugs to <[email protected] 用法
壓縮
[[email protected] ~]$ gzip -v netstat.log
netstat.log: 93.0% -- replaced with netstat.log.gz
[[email protected] ~]$ ll
total 4
-rw-rw-r-- 1 test test 1868 Mar 11 17:11 netstat.log.gz
繼續壓縮
[[email protected] ~]$ gzip -v netstat.log.gz
gzip: netstat.log.gz already has .gz suffix -- unchanged
[[email protected] 解壓縮
[[email protected] ~]$ gzip -v -d netstat.log.gz netstat.log.gz: 93.0% -- replaced with netstat.log
測試完整性
[[email protected] ~]$ gzip -v -t netstat.log.gz
netstat.log.gz: OK
[[email protected] ~]$ touch dummy.gz;gzip -v -t dummy.gz
gzip: dummy.gz: unexpected end of file
列表檔案
[[email protected] ~]$ gzip -v -l netstat.log.gz
method crc date time compressed uncompressed ratio uncompressed_name
defla 73d6b845 Mar 11 16:12 1799 25013 93.0% netstat.log
特點
1.僅能對單個檔案（即輸入一個檔案，輸出一個檔案）
[[email protected] ~]$ mkdir -p foo/bar
[[email protected] ~]$ free > foo/free.log
[[email protected] ~]$ netstat > foo/bar/netstat.log
[[email protected] ~]$ tree .
.
└── foo
├── bar
│ └── netstat.log
└── free.log
2 directories, 2 files
[[email protected] ~]$ gzip foo/
gzip: foo/ is a directory -- ignored
[[email protected] ~]$ gzip foo/*
gzip: foo/bar is a directory -- ignored
2.通過遞迴，支援對資料夾的壓縮(gzip -r)，但解壓縮需單獨一一進行
[[email protected] ~]$ gzip -v -r foo/
foo//bar/netstat.log: 92.5% -- replaced with foo//bar/netstat.log.gz
foo//free.log: 44.8% -- replaced with foo//free.log.gz
3.預設情況下，gzip壓縮後的檔案字尾名為.gz(gzip -S ".your_suffix")
[[email protected] ~]$ gzip -v -S ".gzip" passwd
passwd: 61.4% -- replaced with passwd.gzip
gzip預設字尾為.gz，當更改字尾名後，解壓時，需要指定字尾名
[[email protected] ~]$ gzip -v -d passwd.gzip
gzip: passwd.gzip: unknown suffix -- ignored
[[email protected] ~]$ gzip -v -d -S ".gzip" passwd.gzip
passwd.gzip: 61.4% -- replaced with passwd
4.壓縮、解壓縮時，保留原有檔案許可權
壓縮前，檔案許可權
[[email protected] ~]# ll
total 4
-rw-r--r-- 1 root root 5 Mar 11 16:49 whoami.log
更改許可權為777
[[email protected] ~]# chmod 777 whoami.log
[[email protected] ~]# chown test:test whoami.log
壓縮後，檔案許可權
[[email protected] ~]# gzip -v whoami.log
whoami.log: 120.0% -- replaced with whoami.log.gz
[[email protected] ~]# ll
total 4
-rwxrwxrwx 1 test test 36 Mar 11 16:49 whoami.log.gz
解壓後，檔案許可權
[[email protected] ~]# gzip -v -d whoami.log.gz
whoami.log.gz: 120.0% -- replaced with whoami.log
[[email protected] ~]# ll
total 4
-rwxrwxrwx 1 test test 5 Mar 11 16:49 whoami.log
注：在使用 gzip -c 配合 > 重定向時，相當於建立檔案，此時檔案許可權為於當前使用者設定的許可權。
5.壓縮時，預設狀態下，原檔案會被壓縮後的檔案替換；解壓時類似
此時，可以使用gzip -c > your_file_name來重定向輸出檔案，同時儲存原有檔案。不指定檔案時，預設會輸出到標準輸出stdout上。
壓縮
[[email protected] ~]$ gzip -v -S .gz netstat.log.gz -c > netstat.log.gz.gz
netstat.log.gz: 0.2%
[[email protected] ~]$ ll
total 8
-rw-rw-r-- 1 test test 1799 Mar 11 16:12 netstat.log.gz
-rw-rw-r-- 1 test test 1837 Mar 11 16:17 netstat.log.gz.gz
解壓縮
[[email protected] ~]# gzip -vdc whoami.log.gz > whoami
whoami.log.gz: 120.0%
[[email protected] Workspace]# ll
total 8
-rw-r--r-- 1 root root 5 Mar 11 17:08 whoami
-rw-r--r-- 1 test test 36 Mar 11 17:04 whoami.log.gz
6.壓縮後的文字檔案可以直接使用zcat讀出(zcat your_file_name.gz)
[[email protected] ~]$ zcat netstat.log.gz
Active Internet connections (w/o servers)
Proto Recv-Q Send-Q Local Address Foreign Address State
... ...
bzip2
若說 gzip 是為了取代 compress 並提供更好的壓縮比而成立的，那麼 bzip2 則是為了取代 gzip 並提供更佳的壓縮比而來的。 bzip2 真是很不錯用的東西～這玩意的壓縮比竟然比 gzip 還要好～至於 bzip2 的用法幾乎與 gzip 相同！
bzip2 help
[[email protected] svn]# bzip2 --help
bzip2, a block-sorting file compressor. Version 1.0.5, 10-Dec-2007.
usage: bzip2 [flags and input files in any order]
-h --help print this message
-d --decompress force decompression
-z --compress force compression
-k --keep keep (don't delete) input files
-f --force overwrite existing output files
-t --test test compressed file integrity
-c --stdout output to standard out
-q --quiet suppress noncritical error messages
-v --verbose be verbose (a 2nd -v gives more)
-L --license display software version & license
-V --version display software version & license
-s --small use less memory (at most 2500k)
-1 .. -9 set block size to 100k .. 900k
--fast alias for -1
--best alias for -9
If invoked as `bzip2', default action is to compress.
as `bunzip2', default action is to decompress.
as `bzcat', default action is to decompress to stdout.
If no file names are given, bzip2 compresses or decompresses
from standard input to standard output. You can combine
short flags, so `-v -4' means the same as -v4 or -4v, &c.
使用
gzip的替代工具bzip2，壓縮比較gzip高，用法與gzip類似，不再贅述。
1.壓縮後的文字檔案可以直接使用bzcat讀出
[[email protected] ~]# bzcat netstat.log.bz2
Active Internet connections (w/o servers)
Proto Recv-Q Send-Q Local Address Foreign Address State
... ...