Most common UNIX commands

Command	Meaning	Example
ls	directory listing	ls -al /bin ls -lR ~/Desktop
cd	change to directory	cd cd Desktop cd ~/Desktop cd /etc
pwd	show current directory	pwd
mkdir/rmdir	create/remove directory	mkdir scripting rmdir scripting
chmod	change file/directory permissions	chmod 755 myscript.sh chmod 700 mydirectory chmod 644 myfile
man	on-line help	man man man ls man ascii
cat	show a file's contents	cat /etc/passwd
more	like cat, but page by page	more /etc/passwd cat averylongfile | more
rm	remove file	rm mytestfile
cp	copy file or directory	cp mytestfile yourtestfile cp -r scripts morescripts
mv	rename/move file	mv mytestfile yourtestfile mv mytestfile /dev/null
echo	write arguments to the standard output	echo "Hello" echo $PATH
which	show which executable (if any) will be used	which ls which mozilla which which
grep	search in files	grep -i something *.java
find	find files	find  .  -name \*test\* find . find  .  -name  \*.mp3  -exec play {} \;   find -mtime 0
head / tail	show first/last lines of a file	head -20 myfile tail -20 myfile tail -f myfile
history and bang	show and use history of commands	history !! !23 ls !$
tar	create or unpack archives	tar cvf tarfile.tar *.jpg tar xvf tarfile.tar
top	show list of processes	top -o cpu