Commands in Unix
Commands?
In the non-graphical part of Unix (often known as the shell), commands are
used to get things done. A command is just a name of a program that you
enter at the command line followed by an "enter", whereupon the
program will run. You can supply parameters to the program to get it to do
something differently. One example is the command lpr, which is used
to send documents to a printer.
Tab completion
When you are in the shell and about to enter a command or a filename, you can use a
feature known as "tab completion". This feature allows the system to aid you
when entering long filenames or directory paths. The tab key is used to invoke the
completion.
For example: Enter vim (followed by a blank space) and press TAB
A list with the files in the current directory will appear
Enter the first few characters in a filename or directory name and press TAB again
The shell will now show a list with files and directories containg the characters you entered
This procedure can be repeated until you have completed the correct file
This is a very nice feature when moving between directories in Unix, where pathnames can be very long and
complicated to remember.
Some common commands
Below is a list with some of the most often used commands. To learn more
about a command, issue the command man followed by the command name,
e.g. man lpr. To exit man, press q. Use man to learn
more about the following commands.
| ls |
Lists the files in the current directory |
| pwd |
Shows the path of the current directory |
| cd |
Changes directory |
| cp |
Copies a file |
| mkdir |
Creates a directory |
| rmdir |
Removes a directory |
| rm |
Removes a file |
| man command |
Shows the man page for a command |
| pine |
A simple mail client |
| mutt |
A somewhat more advanced mail client |
| passwd |
Changes the login password |
