Unix Command Summary

• File Manipulation Commands
• Directory Manipulation Commands
• General Commands
• Userid Commands
• Job Control Commands
• Network Commands

Note that some of these commands may not work with all shells.

File Manipulation Commands

cp:

Copies a file from one file or directory to another. e.g. cp /usr/local/software.txt myfile.txt

mv:

Moves and/or renames a file, e.g. mv myfile newfile

more:

Displays the contents of a file in screenfuls, e.g. more newfile

rm:

Removes a file, e.g. rm -i newfile

lpr:

Prints a file on the default printer, e.g. lpr myfile.txt

lpq:

Displays the status of all print jobs you started.

lprm:

Removes print jobs which you want to cancel.

chmod:

Changes the protection on a file or directory. For more information type man chmod

pico, emacs, vi:

These are three of the many text editors available to create and change files. We recommend pico for inexperienced users.

ls:

List what files are available, e.g. ls -al

mkdir:

Create a directory, e.g. mkdir project

rmdir:

Remove directories, e.g. rmdir project

cd:

By itself it moves you to your login directory. Otherwise it moves you to a different directory, e.g. cd /bin

pwd:

Displays what directory you currently are in.

quota:

Displays the amount of free disk space available for your use, e.g. quota -v

alias:

Make command aliases, e.g. alias dir ls

history:

Recall previously typed commands.

passwd:

Change your password.

exit or logout:

Log out of the system. Do this before leaving your terminal so others cannot use your account.

groups:

Displays what groups you belong to. People in the same groups have "group" access to files, as specified using the chmod command.

finger:

Lists people logged into the computer. e.g. finger bob@igor.gold.ac.uk

<, >, |:

Redirect Standard Input and Standard Output. " < " receives input from a file, " > " sends output to a file, " | " sends program output into another command. e.g. ls | grep ".doc" > docs.txt

&:

Follow any command with " & " to have it run in the background. Even if you log off, the program will keep running. You can also use nice to run at a lower priority. e.g. nice ls > list.txt &

^Z:

Press [Control-Z] in most programs to suspend the program and get the Unix prompt.

jobs:

Type "jobs" to list all programs suspended using ^Z. Each job is identified by a number in [ ].

bg:

Send the suspended job into the background, as if you originally started it using the " & " command, e.g. bg [1]

fg:

Bring the suspended job into the foreground so you can continue working, e.g. fg [3]

ps:

List all the processes (programs) currently running. e.g. ps -l

kill:

This command uses the process identification number (pid) given in the "ps" command to stop a running process. e.g. kill -9 90194

rup:

Display information about the running-time of local Unix hosts, along with statistics about the current workload of each host.

rusers:

Display the user-ID of all users connected to local Unix hosts.

rsh:

Run a shell command on a remote Unix host, e.g. rsh spock ls

rlogin:

Login to a remote Unix host, e.g. rlogin scorpio.gold.ac.uk

telnet:

Login to a remote internet host, e.g. telnet aries.gold.ac.uk

ftp:

Connect to a remote internet host using the File-Transfer Protocol, e.g. ftp src.doc.ic.ac.uk

ssh:

Open a secure shell on a remote internet host, e.g. ssh igor.gold.ac.uk

scp:

Copy files to/from a remote internet host using the secure SSL protocol, e.g. scp myfile bob@igor.gold.ac.uk:myfile