**UNIX Command Reference**

The command prompt in UNIX is called the //shell//.  Here is a list of common UNIX commands which will work across many different versions of UNIX with discrepancies in Example/Notes.

||Command||Description||Examples||Notes||
||as||ASsembler||//as input.s//||||
||cc||C Compiler||//cc input.c//||||
||cd||Change working Directory||//cd tmp//||on Version 6 this command is //chdir//||
||df||Disk Free||//df//||May take time to complete on some systems||
||ed||EDitor||//ed filename//||[[ED Survival|ED is the standard (line) text editor]]||
||echo||Echo||//echo ${HOME}//||Prints the value assigned to the variable HOME||
||env||ENVironment settings||//env//||Displays the shell environment settings (see //set//))||
||ld||Link Loader||//ld inputfile//||||
||ls||LiSt directory||//ls -l//||provides a long LiSting||
||man||MANual||//man man//||On some systems, displays online manual pages||
||ps||Process Status||//ps -a// or //ps -l//||prints All or Long Process Status||
||pwd||Present Working Directory||//pwd//||Prints the working directory||
||set||SETting||//set//||Displays the shell environment settings (see //env//)||
||vi||VIsual editor||//vi filename//||[[VI Survival|vi is a screen editor]]||

On some systems typing //games// will print a list of games.

||directory||description||
||/||This is the top level or //root// directory||
||/bin||common user programs are here (type //echo ${PATH}// to see more||
||/etc||This is the system directory||
||/lib||System library files||
||/usr||USeR directory - contains additional binaries, libraries, manpages||