# Linux command cheat sheet
In this cheat-sheet file usually means file or directory
~ is a linux short-hand for your home-directory
| **Command** | **Description/explanation** | **Useful options** | **Examples** |
| ----------- | --------------------------------------------------------------------------------------------------------------- | ---------------------------------------------------------- | ------------------------------------------------------- |
| ssh | secure shell \- remote login to another linux machine | | ssh ola@saga.sigma2.no |
| hostname | Given name to machine | |
| cd | change directory – move around in your file hierarchy | | cd ~/documents |
| pwd | print working directory | | |
| ls | List – list content of directory | \-l,-lh | ls documents |
| echo | print out something | | echo "Hi there" |
| mkdir | Make directory | \-p | |
| cp | copy | | cp file1.txt ~/documents/file2.txt |
| mv | move | | mv file1.txt ~/documents/file2.txt |
| rm | remove | \-f, -r, -i | rm -i file1.txt |
| cat | Cocatenate – used to view contents of a text file
or fill text-file with contents | | cat file1.txt |
| more | View text file in command promt, move
forward one page at a time | | more file1.txt |
| less | Similar to more – but you can move
forwards and backwards | | less file1.txt |
| head | Print out top N lines of text file | \-n | head file1.txt |
| tail | Print out bottom N lines of text file | \-n | tail file1.txt |
| diff | Print out differences between files | | diff file1.txt ~/documents/file2.txt |
| wget | Download files from the internet | | wget https://www.nrk.no |
| tar | Archive or unarchive files | xvf (x: extract v: verbose f: filename)
cvf (c: create) | tar xvf demo-moving-around.tar.gz |
| find | Find files in the file hierarchy | | find file1.txt ~/ |
| touch | Create, modify and change timestamps of a file | | touch newfile.txt
touch existingfile.txt |
| grep | Searches through files and prints out
occurrences of the string grepped | | grep car texaboutcars.txt |
| bash | Sh-compatible command language interpreter | | |
| chmod | change mode – change permission mode
of file – read/write/execute | \-R | chmod u+x file1.exe
chmod 0700 file1.exe |
| sort | Sort the given input | | |
| uniq | Filters out repeated occurences | | |
| wc | Word count | \-l,\-c,\-m | wc textaboutcars.txt |
| history | Show bash history | | |
| xargs | Build and execute command lines
from standard input | | |
| man | Linux manual – all linux commands have
a man page showing required
and optional parameters to the linux command | | man ls |