Basic UNIX Commands

Directory	::
Show current directory	pwd
Show content of directory	ls -al
Changing directory	cd <newdir>
Creating directory	mkdir <dir>
Deleting directory if empty	rmdir <dir>
Deleting directory if full	rm -r <dir>
Moving directory	mv <olddir> <newdir>
Copy directory	cp -r <olddir> <newdir>
Files	::
Show file entry	ls -al <file>
Delete file	rm -i <file>
Move file	mv <file> <path>
Copy file	cp <file> <newfile>
Rename file	mv <oldfile> <newfile>
Show file content at once	cat <file>
Show file content page wise	more <file>
Show file with long lines	cat <file> | fold
Show first 20 lines of file	head -20 <file>
Show last 20 lines of file	tail -20 <file>
Edit file	<editorname> <file>
Edit file with vi	vi <file>
Give all file permissions to yourself	chmod 700 <file>
The above even into subdirectories	chmod -R 700 <dir>
Open file for reading and executing for all	chmod 644 <file>
Starting file as program	<filneame> <arguments>
Find word in file	grep <word> <file>
Find all files which contain a word	grep -l <word> *
Find abstract pattern: ab 2 digits cd	grep 'ab[0-9][0-9]cd' <file>
Comparing two files	diff <file1> <file2>
Updating the date of a file	touch <file>
Giving a specific date to a file	touch 0101010199 <file>
Help	::
Getting help about a command	man <command>
Find command related to a term	man -k <term>
Where is a particular program if it is in the path	which <commandname>
Is a <name> a unix command or an alias in ksh	whence <commandname>
Aliases	::
Making an alias in csh/tcsh	alias <aliasname> '<long_command>'
Making an alias where the arguments go in the middle	alias <aliasneme> '<command> \!* <other>'
Making an alias in sh/bash/ksh	alias <aliasname>='<long_command>'
Using an alias	<aliasname> <arguments>
Use command instead of it's alias	\<command>
Showing all aliases	alias
Remove an alias	unalias <aliasname>
Adjustments	::
See environment variables	env
Setting the term variable if vi doesn't work	setenv term vt100
Opening the X-server for X-clients	xhost +
Setting the display for X-clients	setenv display <computer>:0.0
Internet	::
Telnet to another computer	telnet <computername>
Rlogin to another computer	rlogin -l <username_there> <computername>
Browsing the net with netscape	netscape
Check whether someone is logged in somwhere	finger user@host.domain
Check for all people on another computer	finger @host.domain
Talk to another person on another computer	talk user@host.domain
Ftp building up connection	ftp <computername>
Ftp adjusting for binary transfer	>bin
Ftp showing directory	>dir
Ftp changing directory	>cd /<path>/<path>
Ftp getting a file	>get <file>
Ftp getting multiple files	>mget <filenamecommon>*
Ftp searching for a file	>quote site find <filename>
Get the ip number of a computer	nslookup <computername>
Check whether another computer is up	ping <computername>
Check the pathway to another computer	traceroute <computername>
Info about Unix System	::
See who is logged on	who ... w ... what
Get the date	date
See who logged in lately	last -20
See what operating system is there	uname -a
See who you are	whoami
Get the name of your computer	hostname
See the disk space used	df -k
See you quota usage	quota -v
See how much space all your files need	du -k
Mail	::
Check for mail	from
Read mail	Mail
Compose mail	Mail -s <subject> <mailaddress>
Mail a whole file ( one "<" is real )	Mail -s <subject> <mailaddr> < <file>
Compressing Files	::
Compress 50%	compress <file>
Uncomress the above file.Z	uncompress <file>.Z
Compress 70%	gzip <file>
Uncompress the above file.gz	gzip -d <file>.gz