Basic UNIX Commands

Commonly used Unix commands

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Starting and Ending

login: `Logging in'

telnet: Connect to another machine

logout: `Logging out'

File Management • emacs: `Using the emacs text editor'

mkdir: `Creating a directory'cd: `Changing your current working directory'ls: `Finding out what files you have'cp: `Making a copy of a file'mv: `Changing the name of a file'rm: `Getting rid of unwanted files'chmod: `Controlling access to your files'cmp: Comparing two fileswc: Word, line, and character countcompress: Compress a file

Communication

• e-mail: `Sending and receiving electronic mail'

• talk: Talk to another user• write: Write messages to another user• ftp: `Transferring files with ftp'

Information

• man: Manual pages

• quota -v: Finding out your available disk space quota

• ical: `Using the Ical personal organizer'

• finger: Getting information about a user

• passwd: Changing your password

• who: Finding out who's logged on

Printing

• lpr: `Printing'

• lprm: Removing a print job

• lpq: Checking the print queues

Job control• ps: `Finding your processes'

• kill: `Killing a process'

• nohup: Continuing a job after logout

• nice: Changing the priority of a job

• &: `What is a background process?'

• Cntrl-z: Suspending a process

• fg: `Resuming a suspended process'

Selecting a Unix shell

• sh – The first shell, historically, was sh, also known

as the Bourne shell. It is good for writing shell scripts, but not so popular for interactive use.

• csh – Also known as C-Shell, csh features a syntax

somewhat like the C language. It allows (among other things) adding your own commands (aliasing), history substitution (re-execution of previously typed commands), and filename completion.

• tcsh – This shell allows you to edit your command

line while you're typing it, using emacs-like commands. It has a number of other nifty features, but is otherwise compatible with csh.

• bash – Compatible with sh for programming

purposes, it has many of the good features of csh and tcsh: file name completion, job control, history substitution, emacs command-line editing, and many more.