BASIC LINUX COMMANDS :
1. tty - reveals
the current terminal
2. whoami -
reveals the currently logged-in user
3. which -
reveals where in the search path a program is located
4. echo - prints
to the screen
a. echo $PATH - dumps the current path to
STDOUT
b. echo $PWD - dumps ths contents of the $PWD
variable
c. echo $OLDPWD - dumps the most recently
visited directory
5. set - prints
and optionally sets shell variables
6. clear - clears
the screen or terminal
7. reset - resets
the screen buffer
8. history -
reveals your command history
a. !690 - executes the 690th command in our
history
b. command history is maintained on a per-user
basis via:
~/.bash_history
~ = users's $HOME
directory in the BASH shell
9. pwd - prints
the working directory
10. cd - changes
directory to desired directory
a. 'cd ' with no options changes to the $HOME
directory
b. 'cd ~' changes to the $HOME directory
c. 'cd /' changes to the root of the file
system
d. 'cd Desktop/' changes us to the relative
directory 'Desktop'
e. 'cd ..' changes us one-level up in the
directory tree
f. 'cd ../..' changes us two-levels up in the
directory tree
11. Arrow keys
(up and down) navigates through your command history
12. BASH supports
tab completion:
a. type unique characters in the command and
press 'Tab' key
13. You can copy
and paste in GNOME terminal windows using:
a. left button to block
b. right button to paste OR Ctrl-Shift-v to
paste
14. ls - lists
files and directories
a. ls / - lists the contents of the '/' mount
point
b. ls -l - lists the contents of a directory
in long format:
Includes: permissions, links, ownership, size,
date, name
c. ls -ld /etc - lists properties of the
directory '/etc', NOT the contents of '/etc'
d. ls -ltr - sorts chronologically from older
to newer (bottom)
e. ls --help - returns possible usage
information
f. ls -a - reveals hidden files. e.g.
'.bash_history'
Note:
files/directories prefixed with '.' are hidden. e.g. '.bash_history'
15. cat -
catenates files
a. cat 123.txt - dumps the contents of
'123.txt' to STDOUT
b. cat 123.txt 456.txt dumps both files to
STDOUT
c. cat 123.txt 456.txt > 123456.txt -
creates new catenated file
16. mkdir -
creates a new directory
a. mkdir testRH5 - creates a 'testRH5' directory
17. cp - copies
files
a. cp 123.txt testRH5/
By default, 'cp'
does NOT preserve the original modification time
b. cp -v 456.txt testRH5/
18. mv - moves
files
a. mv 123456.txt testRH5/ - moves the file,
preserving timestamp
19. rm - removes
files/directories
a. rm 123.txt
b. rm -rf 456.txt - removes recursively and
enforces
20. touch -
creates blank file/updates timestamp
a. touch test.txt - will create a zero-byte
file, if it doesn't exist
b. touch 123456.txt - will update the
timestamp
c. touch -t 200801091530 123456.txt - changes
timestamp
21. stat -
reveals statistics of files
a. stat 123456.txt - reveals full attributes
of the file
22. find - finds
files using search patterns
a. find / -name 'fstab'
Note: 'find' can
search for fields returned by the 'stat' command
23. alias -
returns/sets aliases for commands
a. alias - dumps current aliases
b. alias copy='cp -v'
