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jzfrank
jzfrank

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Learn Enough Linux Command Lines to be Dangerous, or to be Safe

#linux

This post lists the most commonly used commands in linux (or alike, like MacOS) system.

File System 

$ whoami
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prints the login name of the current user.

joke

$ pwd
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prints the current working directory (Print Working Directory)

$ ls
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lists files and directories. Often used with options

  • ls -l: -l option signifies the long list forma
  • ls -a: -a option means list hidden files
  • ls -F: -F option makes files of different types appear differently. Display a slash ('/') immediately after each pathname that is a directory, an asterisk ('*') after each that is executable, an at sign ('@') after each symbolic link etc. 
$ cd
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change directory. Note often used:

  • cd .. go to parent directory
  • cd - go to previous directory
  • cd ~ go to home directory 
$ mkdir
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creates a directory

$ rmdir
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removes a (empty) directory

$ cp src dest
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copies files/folders from one location to another

$ mv src dest
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moves files/folders from one location to another

$ rm
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removes files/folders. Often used:

  • rm -r folder_name removes a folder and its content
  • rm -rf folder_name removes without prompts

Processes 

$ ps
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see the processes associated with the current shell. Often used with:

  • ps -ef get a full listing of all processes in the system
  • ps -ef | grep process_name get process_name process 
top
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display the processes using the most CPU time. Often used with:

  • top -n 10 lists the top 10 processes that use the most CPU time

quit with q

kill
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terminates a process kill PID. Use kill -9 PID to force kill.

Misc 

$ vim
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text editors for writing files.
Recommended: install plugins ultimate vim to make vim more powerful and colorful.

$ cat
$ more 
$ less
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view files

$ grep
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search text files

$ gcc 
$ gdb
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compilers and debuggers

More

One can use man to get a detailed explanation of commands

man cp
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