100 common Linux commands

100 common Linux commands

List several commands that are frequently used in linux and give a brief description.

1. export // view all environment variables

2. wc-l // number of rows and wc-w words

3. lsattr file // View file Attributes

4. cat/etc/passwd | awk-F: '{print $1}' // view all users in the system

5. cat/etc/group // view all groups in the system

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 of bad track scanning.

9. time command // view the command running time

10. nmap-sP 172.30.4.0/24 // the number of users in the CIDR block on my host and a good security check tool

11. vgdisplay // view available space in the system

12. lvextend-L + 20G/dev/tank/part1 // Add 20G space to the partition part1

13. lvresize-L-10G/dev/tank/part2 // reduce the space by 10 Gb to the part2 Partition

14. pvdisplay // view disk Information

15. mplayer-loop 10/mnt/song/music/Hua Er opened the loop // played for 10 times

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, and 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 @ phpac] # let a = 34 + 3;

[Root @ phpac] # echo $;

23. 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.

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

28. cal // get a neat calendar format

29. chmod go + w-R/home/zhangy // Add write permissions to group users and other users

30. mirror/mysql // download the mysql directory

31. mirror-R/mysql // upload the mysql directory

32. rmmod pcspkr // turn off the tab prompt

33. modprobe pcspkr // enable the tab prompt

34. gpasswd-a zhangy wheel // Add the user named zhangy to the group

35. dd if =/dev/zero of =/virtual/ubuntu. virt. img bs = 1 M count = 4096 // create a 4g img Image

36. lspic // display the pci device

37. lsusb // display usb devices

38. history | less // less root is a bit more, and it feels more comfortable to use less

39. ln-s // if you forget-s, it turns into a hard link.

40. tar zxvf test.tar.gz-C/home/zhangy // decompress the content to the specified directory.

41. umask 003 u permission is 7, g permission is 7, 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 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 status of Disk/dev/sda2 and refresh 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 programs are running on port 22.

60. lsof-c abc // display the files currently opened by the abc process

61. lsof-p 12 // check the files opened by the process whose process number is 12.

62. rz-y // upload a file

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. ls-lrt // sort by time in reverse order

71. Progress displayed during rsync-P // Synchronization

72. history-c // clear historical commands

73. cd-// return the last directory

74. tree // display the directory tree

75. umount-n/mnt/hda2 // force uninstall

76. Remove Dependencies from pacman-S firefox-nd/nd.

77. wget-c // breakpoint download

78. chroot/mnt/ubuntu // change the root directory to/mnt/ubuntu

79. ctrl + a // run the command line and the light starts with nominal animation.

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 and retrieve the first-four columns after the split

82. file/home/zhangy/test. php // you can view basic information about a 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 current number of disks

86. fdisk-l // view the number of all disks

87. alsamixer // after entering, the m key can be muted.

88. killall httpd // kill all httpd processes.

89. killall-9 mysqld_safe // some process superusers cannot stop, and-9 is forced to delete

90. echo "AaDCbd23" | tr "[A-Z]" "[a-z]" uppercase small write, echo "AaDCbdc23" | tr-c B-d = convert B-d replace string with =

91. echo "ADSF" | iconv-f UTF8-t GBK // convert the character from utf8 to gbk-f. It is from and simplified, and-t is short for terminal.

92. The line number is displayed before cat-n file //.

93. chattr + I file // read-only and root users cannot modify it.

94. tar-tzvf test.tar.gz // list the archived content

95. du-ah // view the file list size

96. du-sh // view the total size of all files

97. groups // check all groups of the current user

98. usermod-g group name user // This method is the overwrite method. Be careful when using it. If user A is used in mysql usermod-g php mysql, only

Php,

99. usermod-G group name user // This method is added. If user A is in mysql usermod-g php mysql, mysql will belong to two groups.

100. bc // enter the math