Computer Handbook

Unix - basic skills

Remember that the working directory in the UNIX window can be completely different from what you see in the file manager. Normally you start in your home directory when you open your UNIX window or your file manager, then you can change directory in both or just one of them.
If you are unsure where in the filetree you are, use following command in your UNIX window:

ra>pwd

and you will get an answer with your present working directory e.g.: ra>/home/pascal/lab1

Remember that UNIX is case sensitive, that 'Myfile' is not the same as 'myfile'.

Each command is written at a single row, with space between each argument, in the terminal window.

The commands are executed with the

button.

Basic commands

cd directory	Change directory; Change working directory to directory.
cd ..	Change the working directory one step up in the file structure. E.g. from `'/edu/yourdirectory/div'` to `'/edu/yourdirectory'`
pwd	Present working directory; Shows your current location in the filetree.
ls	Lists all files and directories in current working directory.
ls -l	List -long; Lists all files and directories, each on a new row. Gives you information about the current state of protection (the rights to read, write and execute) and creation date of the files and directories.
cp fromfile tofile	Copy; Copies the file fromfile and names the copy tofile.
cp ~aaabb123/testfile .	Copy; Copies the file testfile located in the home directory of user 'aaabb123' to current working directory, this is the function of the dot at the end.
Up arrow	This button shows you the last command given to the computer. It can be pressed several times to go further back in the command list.
Down arrow	Vice versa.
mkdir directory	Make directory; Creates a new directory, in current directory, named directory.
mvdir fromdirectory todirectory	Move directory; Moves (or renames) a directory.
mv fromfile tofile	Move; Moves (or renames) a file, or a directory, and all files in that directory.
rm file	Remove; Removes a file. Warning! A very powerful command!
rmdir directory	Remove directory; Removes a directory (the directory must be empty).
chmod a=rwx file	Change mode; Removes all protection from the file and gives you and all persons the right to read, write on and execute 'file'.
lp [-Pprinter] file	Prints file. If the argument '-P' and the name of a specified printer is given, the file is directed to the specified printer
lpq [-Pprinter]	Shows current printer queue and the number of the jobs. With the argument '-P' it shows the printqueue of printer.
lprm [-Pprinter]	Removes all jobs in the printer queue.
lprm [-Pprinter] jobnumber	Removes a specified job.
passwd	Password; Changes your password.
man command	Manual; A help function which shows you the manual pages about command. - Very useful!
	Interupts current program