uname command, 24 uncompress program, 179–180 uncompressing files, 179–180, 182, 195 undeleting files with CDE Trash tool, 66 Uniform Resource Locators. See URLs UNIX case sensitivity, 2 common mistakes, 345–349 determining your version, 23–24 development of multiple versions, 19–20 Internet connection, 227–228 Internet resources, 357 major types, 20–21 personal information on, 220 software used by authors, 5 Usenet news, 355–356 Usenix user group, 360 Windows XP and 2000 versus, 22 UNIX For Dummies (Levine, John R. and Young, Margaret Levine) assumptions about the reader, 2 conventions, 2 icons in book margins, 4 organization, 2–4 overview, 1 software used by authors, 5 Web site, 270 UNIX For Dummies Quick Reference (Levine, John R. and Young, Margaret Levine), 360 UNIX in a Nutshell (O’Reilly), 360 UNIXWare (Novell), 21 UnixWare (Santa Cruz Operation), 21 untar files, 195–196 unzip program, 180, 182 URLs (Uniform Resource Locators) defined, 264 directories in, 101 FTP, 290 going to, in Web browsers, 269–270 for organization home pages, 265 overview, 264 usage error message, 340–341 Usenet news, 244, 355–357 Usenix user group, 360 user groups, 360 username, 14–15, 234–235, 291 users adding in Linux, 212–213 home directory, 94–95, 96–97 root or superuser (Linux), 211 /usr/home or /home directory, 94–95, 96–97, 307