disable an user's account: siwc@claret /usr 214 >grep -i terrence /etc/passwd tbrennan:x:14188:710:Terrence Ian Brennan:/servers/http/webraft/docs:/bin/false twlteh:x:64014:671:Terrence Wei Loong Teh:/servers/http/webraft/docs:/bin/false true, false - provide truth values true does nothing, successfully. false does nothing, unsuccessfully. They are typically used in a shell script |