100 most commonly used linux 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]" in upper case, 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 short write, and-t is like terminal shorthand

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 // know what program is running on port 22

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