51 Useful Yet Lesser Known Commands for Linux Users

51 Highly Useful yet lesser known commands which are very powerful in daily use.

1. sudo!!: Execute the previous command in sudo.
2. Python -m SimpleHTTPServer : Execute a server in the current working directory using port 8000
3. mtr: a combination of ping an traceroute commands
4. Ctrl+x+e: Opens an editor in terminal
5. nl : Outputs the content of text file with lines Numbered
6. shuf : Randomly selects line/file/folder from a file/folder very similar to a shuffle
7. ss : Outputs Socket Statistics.
8. Last: returns the history of the last logged user
9. curl ifconfig.me : Shows machine’s external IP Address.
10. tree : Prints files and folders in tree-like fashion, recursively.
11. Pstree : Prints running processes with child processes, recursively.
12. command : Adding a space before the command ensures the command is not recorded in history
13. stat : Shows the status information of a file as well as of a file system.
14. . And . : A tweak which put the last command argument at prompt, in the order of last entered command, appearing first.
15. Pv: command allows a user to see the progress of data through a pipeline, by giving the following information
16. Mount | column -t : Lists mounted file system, in nice formatting with specification
17. Ctrl + l: clear shell prompt, instantaneously.
18. curl -u gmail_id –silent “https://mail.google.com/mail/feed/atom” | perl -ne ‘print “\t” if //; print “$2\n” if /(.*)/;’. This simple scripts, opens up, unread mail of an user, in the terminal itself.
19. screen : Detach and Reattach, long running process from a session.
20. file : Outputs information, regarding types of file.
21. id : Print User and Group Id.
22. ^foo^bar : Run last command with modification, without the need of rewriting the whole command again
23. > file.txt : Flush the content of a text file, in a single go, from the command prompt.
24. at : Run a particular command, time based.
25. du -h –max-depth=1 Command : Outputs the size of all the files and folders within current folder, in human readable format.
26. expr : Solve simple mathematical calculations from the terminal.
27. look: Lookup for an English word, from the dictionary, in case of confusion, right from the shell
28. yes : continues to print a sting, till interrupt instruction is given.
29. factor: Gives all the possible factors of a decimal number.
30. ping -i 60 -a IP_address : Pings the provided IP_address, and gives audible sound when host comes alive.
31. tac : Prints content of a file, in reverse order.
32. strace : A debugging tool.
33. disown -a && exit Command : Run a command in background, even after terminal session is closed.
34. getconf LONG_BIT Command : Output Machine Architecture, very clearly.
35. while sleep 1;do tput sc;tput cup 0 $(($(tput cols)-29));date;tput rc;done & : The script outputs date and time on the top right corner of shell/ terminal.
36. convert : converts the output of a command in picture, automatically.
37. watch -t -n1 “date +%T|figlet” : Show animated digital clock at the prompt.
38. host and dig : DNS lookup utility.
39. dstat : Generates statistics regarding system resource.
40. bind -p : Shows all the shortcuts available in Bash.
41. Touch /forcefsck : Force file-system check on next boot.
42. lsb_release : Prints distribution specification information.
43. nc -ZV localhost port_number : Check if a specific port is open or not.
44. curl ipinfo.io : Outputs Geographical Information, regarding an ip_address
45. find .-user xyz : Lists all file owned by user ‘xyz’
46. apt-get build-dep package_name: Build all the dependency, automatically while installing any specific package.
47. lsof -iTCP:80 -sTCP:LISTEN. The script, outputs all the service/process using port 80
48. find -size +100M : This command combination, Lists all the files/folders the size of which is 100M or more.
49. pdftk : A nice way to concatenate a lot of pdf files, into one.
50. ps -LF -u user_name : Outputs Processes and Threads of a user.
51. Startx — :1 (This command creates another new X session).