# 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.