Glossary

This section contains an alphabetical overview of common UNIX commands. More information about the usage can be found in the man or info pages.

A

a2ps

Format files for printing on a PostScript printer.

acroread

PDF viewer.

adduser

Create a new user or update default new user information.

alias

Create a shell alias for a command.

anacron

Execute commands periodically, does not assume continuously running machine.

apropos

Search the whatis database for strings.

apt-get

APT package handling utility.

aspell

Spell checker.

at, atq, atrm

Queue, examine or delete jobs for later execution.

aumix

Adjust audio mixer.

(g)awk

Pattern scanning and processing language.

B

bash

Bourne Again SHell.

batch

Queue, examine or delete jobs for later execution.

bg

Run a job in the background.

bitmap

Bitmap editor and converter utilities for the X window System.

bzip2

A block-sorting file compressor.

C

cat

Concatenate files and print to standard output.

cd

Change directory.

cdp/cdplay

An interactive text-mode program for controlling and playing audio CD Roms under Linux.

cdparanoia

An audio CD reading utility which includes extra data verification features.

cdrecord

Record a CD-R.

chattr

Change file attributes.

chgrp

Change group ownership.

chkconfig

Update or query run level information for system services.

chmod

Change file access permissions.

chown

Change file owner and group.

compress

Compress files.

cp

Copy files and directories.

crontab

Maintain crontab files.

csh

Open a C shell.

cut

Remove sections from each line of file(s).

D

date

Print or set system date and time.

dd

Convert and copy a file (disk dump).

df

Report file system disk usage.

dhcpcd

DHCP client daemon.

diff

Find differences between two files.

dig

Send domain name query packets to name servers.

dmesg

Print or control the kernel ring buffer.

du

Estimate file space usage.

E

echo

Display a line of text.

ediff

Diff to English translator.

egrep

Extended grep.

eject

Unmount and eject removable media.

emacs

Start the Emacs editor.

exec

Invoke subprocess(es).

exit

Exit current shell.

export

Add function(s) to the shell environment.

F

fax2ps

Convert a TIFF facsimile to PostScript.

fdformat

Format floppy disk.

fdisk

Partition table manipulator for Linux.

fetchmail

Fetch mail from a POP, IMAP, ETRN or ODMR-capable server.

fg

Bring a job in the foreground.

file

Determine file type.

find

Find files.

formail

Mail (re)formatter.

fortune

Print a random, hopefully interesting adage.

ftp

Transfer files (unsafe unless anonymous account is used!)services.

G

galeon

Graphical web browser.

gdm

Gnome Display Manager.

(min/a)getty

Control console devices.

gimp

Image manipulation program.

grep

Print lines matching a pattern.

grub

The grub shell.

gv

A PostScript and PDF viewer.

gzip

Compress or expand files.

H

halt

Stop the system.

head

Output the first part of files.

help

Display help on a shell built-in command.

host

DNS lookup utility.

httpd

Apache hypertext transfer protocol server.

I

id

Print real and effective UIDs and GIDs.

ifconfig

Configure network interface or show configuration.

info

Read Info documents.

init

Process control initialization.

iostat

Display I/O statistics.

ip

Display/change network interface status.

ipchains

IP firewall administration.

iptables

IP packet filter administration.

J

jar

Java archive tool.

jobs

List backgrounded tasks.

K

kdm

Desktop manager for KDE.

kill(all)

Terminate process(es).

ksh

Open a Korn shell.

L

ldapmodify

Modify an LDAP entry.

ldapsearch

LDAP search tool.

less

more with features.

lilo

Linux boot loader.

links

Text mode WWW browser.

ln

Make links between files.

loadkeys

Load keyboard translation tables.

locate

Find files.

logout

Close current shell.

lp

Send requests to the LP print service.

lpc

Line printer control program.

lpq

Print spool queue examination program.

lpr

Offline print.

lprm

Remove print requests.

ls

List directory content.

lynx

Text mode WWW browser.

M

mail

Send and receive mail.

man

Read man pages.

mcopy

Copy MSDOS files to/from Unix.

mdir

Display an MSDOS directory.

memusage

Display memory usage.

memusagestat

Display memory usage statistics.

mesg

Control write access to your terminal.

mformat

Add an MSDOS file system to a low-level formatted floppy disk.

mkbootdisk

Creates a stand-alone boot floppy for the running system.

mkdir

Create directory.

mkisofs

Create a hybrid ISO9660 filesystem.

more

Filter for displaying text one screen at the time.

mount

Mount a file system or display information about mounted file systems.

mozilla

Web browser.

mt

Control magnetic tape drive operation.

mtr

Network diagnostic tool.

mv

Rename files.

N

named

Internet domain name server.

ncftp

Browser program for ftp services (insecure!).

netstat

Print network connections, routing tables, interface statistics, masquerade connections, and multi-cast memberships.

nfsstat

Print statistics about networked file systems.

nice

Run a program with modified scheduling priority.

nmap

Network exploration tool and security scanner.

ntsysv

Simple interface for configuring run levels.

P

passwd

Change password.

pdf2ps

Ghostscript PDF to PostScript translator.

perl

Practical Extraction and Report Language.

pg

Page through text output.

ping

Send echo request to a host.

pr

Convert text files for printing.

printenv

Print all or part of environment.

procmail

Autonomous mail processor.

ps

Report process status.

pstree

Display a tree of processes.

pwd

Print present working directory.

Q

quota

Display disk usage and limits.

R

rcp

Remote copy (unsafe!)

rdesktop

Remote Desktop Protocol client.

reboot

Stop and restart the system.

renice

Alter priority of a running process.

rlogin

Remote login (telnet, insecure!).

rm

Remove a file.

rmdir

Remove a directory.

rpm

RPM Package Manager.

rsh

Remote shell (insecure!).

S

scp

Secure remote copy.

screen

Screen manager with VT100 emulation.

set

Display, set or change variable.

setterm

Set terminal attributes.

sftp

Secure (encrypted) ftp.

sh

Open a standard shell.

shutdown

Bring the system down.

sleep

Wait for a given period.

slocate

Security Enhanced version of the GNU Locate.

slrnn

text mode Usenet client.

snort

Network intrusion detection tool.

sort

Sort lines of text files.

ssh

Secure shell.

ssh-keygen

Authentication key generation.

stty

Change and print terminal line settings.

su

Switch user.

T

tac

Concatenate and print files in reverse.

tail

Output the last part of files.

talk

Talk to a user.

tar

Archiving utility.

tcsh

Open a Turbo C shell.

telnet

User interface to the TELNET protocol (insecure!).

tex

Text formatting and typesetting.

time

Time a simple command or give resource usage.

tin

News reading program.

top

Display top CPU processes.

touch

Change file timestamps.

traceroute

Print the route packets take to network host.

tripwire

A file integrity checker for UNIX systems.

twm

Tab Window Manager for the X Window System.

U

ulimit

Controll resources.

umask

Set user file creation mask.

umount

Unmount a file system.

uncompress

Decompress compressed files.

uniq

Remove duplicate lines from a sorted file.

update

Kernel daemon to flush dirty buffers back to disk.

uptime

Display system uptime and average load.

userdel

Delete a user account and related files.

V

vi(m)

Start the vi (improved) editor.

vimtutor

The Vim tutor.

vmstat

Report virtual memory statistics.

W

w

Show who is logged on and what they are doing.

wall

Send a message to everybody's terminal.

wc

Print the number of bytes, words and lines in files.

which

Shows the full path of (shell) commands.

who

Show who is logged on.

who am i

Print effective user ID.

whois

Query a whois or nicname database.

write

Send a message to another user.

X

xauth

X authority file utility.

xcdroast

Graphical front end to cdrecord.

xclock

Analog/digital clock for X.

xconsole

Monitor system console messages with X.

xdm

X Display Manager with support for XDMCP, host chooser.

xdvi

DVI viewer.

xfs

X font server.

xhost

Server access control program for X

xinetd

The extended Internet services daemon.

xload

System load average display for X.

xlsfonts

Server font list displayer for X.

xmms

Audio player for X.

xpdf

PDF viewer.

xterm

Terminal emulator for X.

Z

zcat

Compress or expand files.

zgrep

Search possibly compressed files for a regular expression.

zmore

Filter for viewing compressed text.