100 practical shell commands

1. Echo "AA"> test.txt and echo "BB"> test.txt //> clear the original file and write the content to the file.> put the content at the end of the file.
2. chmod go + w-r/home/zhangy // Add write permissions to group users and other users
3, tar-tzvf test.tar.gz // list the archive content
4, Du-Ah // view the file list size
5, Du-SH // view the total size of all files
6, Echo '1 + 2' | BC-l // mathematical operation
7. uname-A // view the Linux kernel and other information
8. badblocks-S/dev/SDA // shows the progress during bad track scan.
9, Time Command // view the command running time
10, LS-LRT // sort by time in reverse order
11. Rsync-P // The synchronization progress is displayed.
12. History-C // clear historical commands
13, CD-// returns the last directory
14. Tree // display the directory tree
15, umount-N/mnt/hda2 // force uninstall
16, Echo ~ /// Display the user's home directory
17, Echo $ [5*5] // arithmetic operation
18, Echo $ (5*5) // arithmetic operation
19, Eval ls; PS aux | grep httpd // both commands can be executed
20, free-M // memory displayed in MB
21. uptime // shows how long the system has been running. It displays the following information in sequence: current time, how long the system has been running, how many login users are there, the average load of the system in the past 1 minute, 5 minutes, and 15 minutes
22. addition operation
[Root @ krlcgcms01 mytest] # Let A = 34 + 3;
[Root @ krlcgcms01 mytest] # echo $;
23, export // view all environment variables
24, Echo $ PATH // view a single variable
25, CMP file1 file2 // File Content Comparison
26, clear // clear screen
27, Echo 23423 | awk -- Re-interval '/[0-9] {3,}/' // if re-interval is not added, it is not displayed
28, Cal // get a neat calendar format
29, WC-l // number of statistical rows, WC-W statistical words
30, Echo "aadcbd23" | TR "[A-Z]" "[A-Z]" Small write, echo "aadcbdc23" | tr-c B-d = replace a string other than B-d with =
31, Echo "adsf" | iconv-F utf8-t gbk // convert the character from utf8 to GBK-F is from and simplified, and-T is short for terminal.
32, cat-N file // The line number is displayed before the content
33. chattr + I file // read-only, and cannot be modified by the root user
34, lsattr file // View File Attributes
35, CAT/etc/passwd | awk-F: '{print $1}' // view all users in the system
36, CAT/etc/group // view all groups in the system
37. Groups // check all groups of the current user
38. usermod-G group name users // This method is covered. Be careful when using this method. If user a is similar to MySQL usermod-g php MySQL, only
PHP,
39. usermod-G group name user // This method is added. If user a is like MySQL usermod-g php MySQL, MySQL will belong to two groups.
40, BC // enter the mathematical computation
41. umask 003 U permission is 7, G permission is 7, and other users are 4, that is, 774,777-003 = 774
42. mkfs-T vfat/dev/hda6 // format a partition in the mobile hard drive into vfat format.
43. Mount/dev/CDROM/Media/CDROM // Mount CDROM
44, getent group 532 // you can use the group ID to find the group information.
45. Last // logon success user record
46. lastb // records of unsuccessful logon users
47. Dump-S/dev/sda2 // check the capacity to be backed up by/dev/sda2.
48, dump-0j-F/dev/hda2/sda2_bak.dump.bz2/dev/sda2 // back up and compress sda2
49. Restore-T-F/dev/hda2/sda2_bak.dump // view the backup information
50, restore-r-F/dev/hda2/sda2_bak.dump // restore the backup
51, FC-list // view the fonts INSTALLED IN THE SYSTEM
52, find./-type F-exec grep-Q "root" {}\;-exec echo {}\; // find the character string contained in the file in the directory
53. vmstat 5 // displays the system information, CPU, memory, and I/O information every 5 times.
54. Sorting of Shift + P processes after top
55. Sort the memory occupied by SHIFT + m after top
56, iptraf-G // view the traffic of each interface
57. ostat-D-x/dev/sda2 2 // use iostat to view disk I/O information of Disk/dev/sda2, Which is refreshed every two seconds.
58, paste-sd' | \ n' test // each of the four lines of the file is converted into one line and separated by |.
59, lsof-I: 22 // You know what port 22 is running. Program
60, lsof-c abc // display the files currently opened by the ABC process
61, lsof-p 12 // check which files are opened by the process whose process number is 12
63, route // view route information
64, IFUP // enable the NIC
65, ifdown // disable the NIC
66, route del-net 172.160.0 netmask 255.255.0.0 Dev eth0 // Delete the 172.168 CIDR Block
67, route add-net 172.1610.0 netmask route 255.255.0 Dev eth0 // Add a route
68, netstat-tunl // list the listening network service ports
69, netstat-tun // list the connected network service ports
70, NMAP-SP 172.30.4.0/24 // how many users are operating on my host in this network segment, a good security check tool
71. vgdisplay // view available space in the system
72, lvextend-L + 20g/dev/tank/Part1 // Add 20g space to the partition Part1
73, lvresize-L-10G/dev/tank/Part2 // reduce the space by 10 Gb to the Part2 Partition
74, pvdisplay // view disk Information
75, mplayer-loop 10/mnt/song/music/Hua Er opened the loop // played for 10 times
76, pacman-s Firefox-nd // nd remove Dependencies
77, wget-C // breakpoint download
78, chroot/mnt/Ubuntu // change the root directory to/mnt/Ubuntu
79, CTRL + A // under the command line, the light starts with nominal Motion
80, CTRL + E // move the cursor to the end of the command line
81, cut-D:-F 1-4 test // use: to split the file, take the first-4 columns after the split
82, file/home/zhangy/test. php // used to view some basic information about the file
83, touch test.txt // create an empty file text.txt
84, htpasswd-CBD/usr/local/nginx/CONF/AuthFile // create an access control file
85, DF // view the disk space and the current number of disks
86, fdisk-l // view the number of all disks
87. After alsamixer // enters, the M key can be muted.
88, killall httpd // kill all httpd Processes
89, killall-9 mysqld_safe // some process superusers cannot stop,-9 is force Delete
90, mirror/MySQL // download the MySQL directory
91, mirror-r/MySQL // upload the MySQL directory
92, rmmod pcspkr // turn off the tab prompt
93, modprobe pcspkr // enable the tab prompt
94, gpasswd-A zhangy wheel // Add the user zhangy to the group
95, dd If =/dev/Zero of =/virtual/ubuntu. virt. img bs = 1 m COUNT = 4096 // create a 4g img Image
96, lspic // display PCI device
97, lsusb // display USB device
98, history | less // less root is more like, it feels more comfortable to use less
99, Ln-S // if you forget-S, it turns into a hard link.
100, tar zxvf test.tar.gz-C/home/zhangy // decompress the content to the specified directory