– Getting to know about the basic Linux commands is a good start to learn it.
– As Linux is preferably administered by the “command line” mode, to know about its commands is the necessity to master it.
– In Linux there are thousands of commands available, we will look into few of the basic commands.
– We have categorized the commands into following sections for better understanding. It will not be difficult to grasp them if you are aware of MS-DOS commands.
– We have covered nearly 60 commands below.
Basic File/Directory Commands
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– We have covered few file & directory related commands, so as to make you aware of basic file and directory management things, so that you can do simple stuff efficiently.
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1. dir – Used to list directory contents
e.g. # dir (it will list the directory contents)
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2. touch – To create an empty file or to update the access time for file.
e.g. # touch file1
# touch
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3. mkdir -To make the directory
e.g. # mkdir /mike
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4. cat – To view the file contents or to concatenate files and print.
e.g. # cat file1
# cat file1 file2
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5. cp – To copy the file
e.g. # cp /tmp/file1 /root/file1
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6. mv – To move file from one place to another
e.g. # mv /tmp/file1 /root/file1
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7. rm – To remove/delete the files
e.g. # rm file1
# rm file1 file2
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8. rmdir – To remove the directory
e.g. # rmdir
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9. more – To view file in page wise in forward direction
e.g. # more file1
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10. less – To list the contents of file page wise
e.g. # less file1
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11. head – Show selected starting lines from file
e.g. # head file1
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12. tail – To show selected lines from end of the file
e.g. # tail file1
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13. rename – To rename a file
e.g. # rename file1 file2
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14. vi -vi editor, to edit files
e.g. # vi file1
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15. wc – To get the content statistics about file, like no. of lines, no of bytes etc
e.g. # wc -l file1
# wc -c file1
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16. zip – To compress a file
e.g. # zip file
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17. cd – To change the current working directory
e.g. # cd
# cd /root
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Getting to know
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18. logname – Print users login name.
e.g. # logname
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19. cal – Calendar
e.g. # cal
# cal 2001
# cal 5
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20. date – Date of the system
e.g. # date
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21. ddate – To converts Gregorian dates to Discordian dates
e.g. # ddate
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22. id – print real and effective user and group IDs
e.g. # id root
# id -a root
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23. finger – Its user information lookup program
e.g. # finger root
# finger mike
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24. w – Show who is logged on and what they are doing.
e.g. # w
# w -h
# w -u
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25. who – show who is logged on.
e.g. # who
# who -all
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26. whoami – Print effective userid.
e.g. # whoami
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27. last – Show listing of last logged in users.
e.g. # last
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28. lastlog – reports the most recent login of all users or of a given user
e.g. # lastlog
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29. file – Determine File type
e.g. # file file1.txt
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30. hostname – Show or set the system host name
e.g. # hostname
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31. mail – Send and receive Internet mails.
e.g. # mail
# mail -u root
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32. uptime – Tell how long the system has been running.
e.g. # uptime
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33. ls – To list the present directory
e.g. # ls
# ls -l
# ls -lh
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34. df – Report file system disk space usage
e.g. # df
# df -h
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35. logname – print user’s login name
e.g. # logname
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36. free – Display amount of free and used memory in the system
e.g. # free
# free -m -t
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37. pinky – Its a lightweight finger
e.g. # pinky root
# pinky -l root
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38. stat – Display file or file system status
e.g. # stat file1
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To Get Help – Commands
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39. –help – To display helpful info about commands
e.g. # ifconfig –help
# ls –help
# w –help
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40. info – Read info doc
e.g. # info ls
# info who
# info ifconfig
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41. man – To format and display the on-line manual pages
e.g. # man ls
# man w
# man ifconfig
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42. whatis – search the whatis database for complete words
e.g. # whatis ls
# whatis w
# whatis who
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43. whereis – locate the binary, source, and manual page files for a command
e.g. # whereis who
# whereis ls
# whereis uptime
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44. which – shows the full path of (shell) commands
e.g. # which ls
# which who
# which uptime
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Miscellaneous Commands
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45. history – Display users command history
e.g. # history
# history -c (To clear the history)
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46. find – search for files in a directory hierarchy
e.g. # find / -name santosh
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47. locate – Find the files
e.g. # locate santosh
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48. poweroff – To stop the system
e.g. # poweroff
# poweroff -f (Forcefully)
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49. shutdown – To bring the system down
e.g. # shutdown
# shutdown -r (reboot)
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50. halt – To bring system down
e.g. # halt
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51. reboot – To reboto the system
e.g. # reboot
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52. logout – To logout from the current session
e.g. # logout
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53. exit – To close the current session
e.g. # exit
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54. lpq – show printer queue status
e.g. # lpq (Should have defaulf printer configured)
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55. cancel – Cancel print jobs
e.g. # cancel 1
# cancel -U root 1
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56. passwd – To change user password
e.g. # passwd (To change self password)
# passwd mike (To change santosh’s passwd)
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57. ping – send ICMP ECHO_REQUEST to network hosts, to see other host responding or not
e.g. # ping 192.168.222.111
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58. runlevel – To see the cureent runlevel
e.g. # runlevel
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59. sort – To sort the command outputs
e.g. # cat file1 | sort
# ls -l | sort
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60. su – To switch to another user
e.g. # su – (To switch to root)
# su – mike (To switch to mike)
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