Basic UNIX Commands

Basic UNIX Commands

Here is a short list of basic UNIX commands. Remember that help via the man command is

available for each of these commands. Simply type man command at a UNIX shell prompt.

General Commands

cd Changes current working directory

cp Copies a file

history Lists previous commands

ln Creates a link

ls Lists contents of directory

mkdir Creates a new directory

mv Moves or renames files

pwd Prints current working directory name

rm Removes files and links

rmdir Removes a directory

Archiving

compress Reduces the size of a files/directories

tar Archives files and directories

uncompress Restores compressed files to their original form

Communications

finger Displays information about a user or users

sftp Securely transfers files

scp Securely copies files

mail Sends and receives electronic mail from local mailbox

rlogin Logs a user into a remote machine

ssh Securely connects a user to a remote machine

talk/ytalk Initiates a conversation with another user

who Lists users who are logged into the machine

whoami Prints current effective login ID

File Manipulation

apropos Locates commands by keyword

awk Scans and processes patterns

cat Concatenates files

cmp Compares two files

diff Displays differences between pairs of text files

find Finds files

grep, egrep, fgrep Searches a file for a pattern

head Gives first few lines of file

man Finds and displays information on UNIX commands and utilities

more, page, less Display text files page-by-page

sed Edits text from an input stream

tail Displays the last part of a file

troff Formats and typsets text

Process Control

bg Places a stopped process in the background

fg Places a stopped process in the foreground

jobs Gives a list of current processes created from this shell

kill Sends a signal to the specified process

ps Gives process status

Miscellaneous

cal Displays a simple text calendar

chmod Changes file permissions

clear Clears terminal screen

csh Invokes a shell (command interpreter) with C-like syntax

date Displays the date and time

du Summarizes disk usage

from Displays a list of messages in the account’s local mailbox

hostname Displays name of the current host system

script Makes a transcript of a terminal sessions

sh Invokes the Bourne shell

stty Sets and displays terminal options

tset Initializes a terminal

tty Gets terminal name

umask Sets/gets the default file permission mask

whatis Describes what a command is

whereis Locates a binary and/or manual page for program

which Locates a program file, including aliases and paths

tokens Shows the user’s AFS tokens

unlog Removes the user’s AFS tokens, disabling authenticated access to AFS files