List of (Semi-)Common Linux Commands
====================================

Getting help (besides Googling):

- ``man``: shows the manual pages of a command, use :kbd:`q` to quit it, use :kbd:`/` to go to search mode.
  After typing something to search for, press :kbd:`Enter` and then use :kbd:`n` (or :kbd:`N`) to go to the next (or previous) occurrence.
- ``--help``: a flag for most commands, used to give a description of the command and its flags (e.g. ``touch --help``).

Basic navigation, file handling, and terminal usage:

- ``pwd``: print name of current/working directory.
- ``ls``: list directory contents.
- ``ls -a``: also hidden files.
- ``cd``: change directory.
- ``mkdir``: make a new directory in current directory.
- ``rmdir``: remove empty directory .
- ``rm``: remove files.
- ``rm -r``: remove directory and the files contained in it (recursively).
- ``cp``: copy a file or directory.
- ``mv``: moves files and directories, can also be used to rename files ("move a file to a new name``).
- :kbd:`tab`: auto complete commands, flags, files, folders, flags, ... almost anything.
- ``touch``: create an empty file, or update modification timestamp on a file.
- ``chmod``: change permissions for a file, such as read and write access.
- ``locate``: locate files/folders (may not be installed as default). Requires running ``updatedb`` reqularly to update the search index.
- ``find``: find files/folders in the current working directory or subdirectories. Does not require ``updatedb``.
- ``clear``: clear terminal window (scroll it).

Less basic file and data manipulation:

- ``echo``: print a string either to console or a file.
- ``cat``: concatenate files and print on the standard output.
- ``less``: show files/input in a scrollable way. Use :kbd:`q` to quit.
- ``tar``: compress/extract files to/from ``.tar.gz`` files.
  Similar to ``zip``/``unzip``.
- ``zip``: compress files to a ``.zip`` file.
- ``unzip``: extract files from ``.zip`` files.
- ``wc``: count lines, words, bytes.
- ``grep``: print lines that match patterns.
- ``sed``: filter and transform text.
- ``diff``: compare files line by line
  (``diff -u`` produces a, perhaps, easier to read format).

Editors:

- ``nano``: a very basic terminal-based text editor.
  Use :kbd:`Ctrl` + :kbd:`x` to quit.
- ``vim``: an advanced terminal-based text editor.
  Use :kbd:`:q` :kbd:`Enter` to quit.
- ``emacs``: an advanced terminal-based text editor.
- ``gedit``: a graphical text editor.

Informational commands:

- ``df``: check the disk space usage on your system.
- ``du``: check the disk space usage for all files in the current directory.
- ``uname``: print system information (often called as ``uname -a``).
- ``hostname``: display the DNS name of your system.
- ``ping``: check if a IP address is live. Can also be used on URLs.

Administration:

- ``sudo``: run commands with administrative or root privileges.
- ``apt`` (or ``apt-get``): command for installing software on Ubuntu
  (also in WSL).

Program (job) control and information:

- :kbd:`Ctrl` + :kbd:`c`: stop a program.
- :kbd:`Ctrl` + :kbd:`z`: suspend a program.
- ``fg``: continue a suspended program.
- ``jobs``: display status of programs (in this terminal).
- ``top``: display currently running programs on the computer
  with CPU and memory usage. Use :kbd:`q` to quit.
- ``ps``: list currently running programs on the computer.