Compression and decompression
Earliest: compress / uncompress filename suffix:. Z
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Then: gzip/gunzip filename suffix:. gz
For a long time, gzip was the standard compression and decompression algorithm of linux
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Then: bzip2 / bunizp2 filename suffix:. bz2
The compression ratio of large files is a little larger than that of gzip, but the compression ratio of small files is not as large as that of gzip, so it fails to shake the position of gzip
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Then: xz/unxz filename suffix:. xz
Significantly improved compression ratio, shaking the position of gzip
lzma/unlama filename suffix:. lzma
The most common (so supported by the operating system): zip/unzip
Linux Archive: the above compression tools can only compress files, not directories. To compress the directory, you must archive it before compressing the archive file.
- tar，cpio
gzip/gunzip/zcat
1. Compress: gzip file
After compression, the original file will be deleted automatically
# ll -h messages -rw-------. 1 root root 915K Feb 11 22:05 messages [root@localhost ~]# gzip messages [root@localhost ~]# ll -h messages.gz -rw-------. 1 root root 167K Feb 11 22:05 messages.gz
2. Decompress: gzip -d or gunzip
After decompression, the compressed file will be deleted automatically
# gunzip messages.gz [root@localhost ~]# ll -h messages -rw-------. 1 root root 915K Feb 11 22:05 messages # gzip -d messages.gz [root@localhost ~]# ll -h messages* -rw-r--r--. 1 root root 915K Feb 11 22:06 messages
3. Specify the compression ratio, which is 6 by default. The larger the compression ratio, the smaller the space of the compressed file. The range is 1-9.
# gzip -9 messages [root@localhost ~]# ll -h messages.gz -rw-r--r--. 1 root root 164K Feb 11 22:06 messages.gz
4. Keep the original file after compression: gzip file - C > zxx.gz
# gzip -c messages > messages.gz [root@localhost ~]# ll -h messages* -rw-------. 1 root root 915K Feb 11 22:05 messages -rw-r--r--. 1 root root 167K Feb 11 22:06 messages.gz
5. Check the contents of the compressed file directly without decompressing: zcat messages.gz
bzip2/bunzip2/bzcat
1. Compress: bzip2 file
After compression, the original file will be deleted automatically
# ll -rw-r--r--. 1 root root 936782 Feb 11 22:06 messages # bzip2 messages # ll -rw-r--r--. 1 root root 69193 Feb 11 22:06 messages.bz2
2. Decompress: bzip2 -d or bunzip2
After decompression, the compressed file will be deleted automatically
# bzip2 -d messages.bz2 [root@localhost ~]# ll messages -rw-r--r--. 1 root root 936782 Feb 11 22:06 messages # bunzip2 messages.bz2 [root@localhost ~]# ll -rw-r--r--. 1 root root 936782 Feb 11 22:06 messages
3. Specify the compression ratio, which is 6 by default. The larger the compression ratio, the smaller the space of the compressed file. The range is 1-9.
# bzip2 -9 messages [root@localhost ~]# ll -rw-r--r--. 1 root root 69193 Feb 11 22:06 messages.bz2
4. Keep the original file after compression: gzip file -k
# bzip2 -k messages [root@localhost ~]# ll messages* -rw-r--r--. 1 root root 936782 Feb 11 22:06 messages -rw-r--r--. 1 root root 69193 Feb 11 22:06 messages.bz2
5. Check the contents of the compressed file directly without decompressing: bzcat messages.bz2
xz/unxz/xzcat and lzma/unlzma/lzcat
1. Compression: xz file
After compression, the original file will be deleted automatically
# xz messages [root@localhost ~]# ll -rw-r--r--. 1 root root 57328 Feb 11 22:06 messages.xz
2. Decompress: xz-d or unxz
After decompression, the compressed file will be deleted automatically
# xz -d messages.xz [root@localhost ~]# ll -rw-r--r--. 1 root root 936782 Feb 11 22:06 messages # unxz messages.xz # ll -rw-r--r--. 1 root root 936782 Feb 11 22:06 messages
3. Specify the compression ratio, which is 6 by default. The larger the compression ratio, the smaller the space of the compressed file. The range is 1-9.
# xz -9 messages [root@localhost ~]# ll -rw-r--r--. 1 root root 57328 Feb 11 22:06 messages.xz
4. Keep the original file after compression: xz file -k
# xz -k messages [root@localhost ~]# ll -rw-r--r--. 1 root root 936782 Feb 11 22:06 messages -rw-r--r--. 1 root root 57328 Feb 11 22:06 messages.xz
5. Check the contents of the compressed file directly without decompressing: xzcat messages.xz
File
1. Create an archive
-Option c: create Archive
-f option: filename of the archive
The bar can be left blank, but f must be put at the end, because the following parameter: the archive file name is for the f option
# ls anaconda-ks.cfg initial-setup-ks.cfg messages messages.xz [root@localhost ~]# tar cf me.tar messages messages.xz [root@localhost ~]# ls anaconda-ks.cfg initial-setup-ks.cfg messages messages.xz me.tar
2. View the file list in the archive
-t option: view the list of files in the archive
# tar tf me.tar messages messages.xz
3. Archive
-x option: expand Archive
If you do not use - C, you will expand to the current directory. If you use - C, you will expand to the specified directory.
# tar xf me.tar -C /tmp # ls /tmp/ messages messages.xz
4. Compress archives
Archive files can be compressed with gzip, bzip2 and xz
# gzip me.tar # ll me.tar.gz -rw-r--r--. 1 root root 228051 Feb 12 08:53 me.tar.gz
Archive and compress
Archiving and compression can be done together
1. After archiving, compress / decompress with gzip algorithm
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Compression: zcf
# tar zcf me3.tar.gz messages messages.xz # ll me3.tar.gz -rw-r--r--. 1 root root 228044 Feb 12 11:43 me3.tar.gz
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Unzip: zxf
# tar zxf me3.tar.gz
2. After archiving, compress / decompress with bzip2 algorithm
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Compression: jcf
# tar jcf me3.tar.bz2 messages messages.xz
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Decompression: jxf
# tar jxf me3.tar.bz2
3. After archiving, compress / decompress with xz algorithm
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Compression: Jcf
# tar Jcf me4.tar.xz messages messages.xz
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Unzip: Jxf
# tar Jxf me4.tar.xz
zip/unzip: archive and compress
# zip me.zip messages messages.xz # unzip me.zip
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