1. Permissions specify who can do what to a file or directory.

    Quick Reference Guide for Commands using files or Directories

Permissions		Files				Directories
-----------     	----- 				-----------   

r - read		cat, more, cp, lp		ls
			<, sort, grep			list the contents
							of a directory

w - write (modify)	modify the contents		cp,rm,mkdir,
			of the file, >, >>		rmdir, add or
							delete files and
							subdirectories
							within

x - execute (access)	use the file name as		Access into the
			a command			directory using
							cd, Access to 
							files and 	
							subdirectories
							within (provided
							you have 'r' 
							permission or 
							know the name
							of the file)

s - Set user or group id	execute the file name
				as a command and take
				on the privileges of the
				owner or group for that
				file only while it is running


t - Sticky Bit			execute the file name as
				a command and keep the
				program on the swap device
				thereafter

l - lock during access		execute the file name as
(System V only)			a command and prevent
				anyone else from executing
				it while it is running
				(Not on all implementations)

Questions? Robert Katz: katz@cis.highline.edu
Last Update July 9, 2002