Archive and compress files

Advantages of archiving and compressing files: Saves disk resources and speeds up file transfer rate. The tar command is used to package and compress files123456 is packaged into a single A.tar file, but the A.tar file is still very large and is compressed using gzip to make it a smaller compressed file.

Function: package, compress files; A tar file is a collection of several files and/or directories in a single file that can be transferred with row compression using a compression tool such as gzip, bzip2, or Xz

[OPTION…] [OPTION…] [OPTION…] [OPTION…] [FILE]… Parameters:

-v --verbose displays the detailed process. -f --file Specifies the backup file. -t --listList the files included in the package, unwrap the package, and look at the contents of the package -c (uppercase) --directoryCopy the code

Specify the unzip location

Example 1: Package the /boot/grub2 directory

[root@xuegod63 ~]# tar -cvf grub.tar /boot/grub2/
[root@xuegod63 ~]# tar cvf grub.tar /boot/grub2/
[root@xuegod63 ~]# tar cf grub.tar /boot/grub2/
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/boot/grub2: /boot/grub2: /boot/grub2: /boot/grub2: /boot/grub2: /boot/grub2

[root@xuegod63 ~]# tar -cf grub.tar /boot/grub2/
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Tar: Remove the leading “/” from the member name

[root@xuegod63 ~]# ls grub.tar
[root@xuegod63 ~]Tar XVF grub.tar
boot/grub2/
boot/grub2/device.map
[root@xuegod63 ~]Get the boot directory
grub2
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Example 2: Package two directories or directories + files into one archive:

root@xuegod63 ~]# mkdir ./back
[root@xuegod63 ~]# cp /etc/passwd ./back/
[root@xuegod63 ~]# tar -cvf back.tar /boot/grub /root/back/ /etc/passwdTar: Remove the starting "/" -rw-r--r-- root/root from the member name1024 2020- 06- 28 19:46-rw-r--r-- root/root5130 2020- 06- 28 19:46 boot/grub2/grub.cfg
drwxr-xr-x root/root   0 202007 -- 03 14:23 root/back/
-rw-r--r-- root/root    2735 202007 -- 03 14:23 root/back/passwd
-rw-r--r-- root/root    2735 2020- 06- 28 19:49 etc/passwd
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Example 3: Unwrap the package and view the contents of tar:

[root@xuegod63 ~]# tar -tvf back.tar # List all files in archive.tar verbosely.
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Example 4: Compare the effect of adding V

root@xuegod63 ~]# tar -xf back.tar
[root@xuegod63 ~]# tar -xvf back.tar
boot/grub/
boot/grub/splash.xpm.gz
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Tar archive + compression

Gz SOURCE syntax: tar CZVF Compressed file name (tar.gz tar.bz2) Files or directories to be compressed Common parameters are as follows:

-z, --gzip Compressed in gzip mode Extension: tar.gz -j: compressed in Bz2 mode extension: tar.bz2 -j: compressed in Xz mode Extension: tar.xzCopy the code

Example 1: Creating the.tar.gz package

[root@xuegod63 ~]# tar cvf /root/etc.tar /etc
[root@localhost test]# tar ZCVF /root/ et.tar. gz /etc
[root@localhost test]Tar ZXVF /root/et.tar. gz
[root@localhost test]# tar XVF /root/etc. Tar. gz
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Example 2: Creating the.tar.bz2 package

Grammar:#tar jcvf newfile.tar.bz2 SOURCE
[root@xuegod63 ~]# tar -jcvf ~/etc.tar.bz2 /etc
[root@xuegod63 ~]# tar -jxvf ~ /etc/tar. bz2
[root@xuegod63 ~]Tar -xvf ~ /etc/tar. bz2
[root@xuegod63 ~]# tar JXVF ~ /etc/tar. bz2 -c /opt
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Example 3: Creating the.tar.xz package

[root@xuegod63 ~]# tar -Jcvf ~/etc.tar.xz /etc
[root@xuegod63 ~]#tar -jxvf ~ /etc/tar.xz #tar
[root@xuegod63 ~]# tar -xvf ~/etc.tar.xz
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Compare the compression ratio of the three compression modes:

[root@xuegod63 ~]# time tar zcf /root/etc.tar.gz /etc
[root@xuegod63 ~]# time tar jcf /root/etc.tar.bz2 /etc
[root@xuegod63 ~]# time tar Jcf /root/etc.tar.xz /etc
[root@xuegod63 ~]# ll -h etc. Tar *
-rw-r--r-- 1 0 root  28M 5 月   10 12:10 etc.tar
-rw-r--r-- 1 0 root  8.7M 5 月   10 12:14Etc. Tar. Commonly used.bz2 # - rw - r - r -1 0 root  9.8M 5 月   10 12:11/etc/tar. gz # common -rw-r--r--1 0 root  7.0M 5 月   10 12:16/etc/tar. xz # this is the highest compression ratio and the longest compression timeCopy the code

Check the source file size

[root@xuegod63 ~]# du -sh /etc
31M /etc
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The etc. Tar package is 28 megabytes, which is actually barely compressed. Xz is formatted as 7.0M, which is much more efficient when transferring.

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