1. The History of the UNIX System Page 1 1.1. Modest Beginnings Page 1 1.2. The Seventies Page 3 1.3. The Eighties Page 3 1.4. Into the Nineties Page 4 1.5. Versions of UNIX Page 5 1.6. UNIX Innovations Page 7 2. Fundamentals Page 9 2.1. The Old Way—Minicomputers Page 9 2.2. And the New Way—PCs and Workstations Page 12 2.3. Operating Systems Page 12 2.4. Multitasking Page 14 2.5. Networking Page 14 2.6. The Kernel Page 15 2.7. Programs and Processes Page 15 2.8. The Vi Text Editor Page 16 2.9. The UNIX Shell Page 17 3. UNIX System Basics Page 19 3.1. Logging in Page 19 3.1.1. Logging in Using a Terminal or PC Page 20 3.1.2. Logging in Using a Workstation Page 21 3.2. Some Simple Commands Page 23 3.3. Files and Directories Page 24 3.4. UNIX System Dialogs Page 26 3.5. Logging Out Page 29 3.6. The UNIX User’s Reference Page 30 4. Entering Commands Using the Shell Page 33 4.1. Unix System Shells Page 34 4.2. Simple Shell Commands Page 35 4.3. Command Arguments Page 35 4.4. Background Processes Page 37 4.5. The Standard Output and the Standard Input Page 39 4.5.1. Output Redirection Page 40 4.5.2. Appending Output Redirection Page 41 4.5.3. Redirecting the Standard Error Page 42 4.5.4. Input Redirection Page 43 4.5.5. Pipes Page 45 4.6. Metacharacters and File Name Generation Page 49 4.7. Disabling Special Characters Page 52 5. The UNIX File System Page 54 5.1. UNIX File Types Page 55 5.1.1. Ordinary Files Page 56 5.1.2. Directory Files Page 58 5.2. The Hierarchical File System Page 59 5.3. Pathnames Page 61 5.4. File Access Modes Page 62 5.5. Directory Access Modes Page 66 6. Managing Your Files Page 68 6.1. Pwd and Cd—The Current Directory Page 69 6.2. Ls—List Files Page 70 6.3. Rm—Remove Files Page 77 6.4. Managing Files with Mv, Cp, and Ln Page 78 6.4.1. Mv—Move Files Page 78 6.4.2. Cp—Copy Files Page 79 6.4.3. Ln—Create Links Page 80 6.4.4. Hard Links Versus Symbolic Links Page 81 6.4.5. Creating Symbolic Links with Ln Page 83 6.5. Chmod—Change File Modes Page 84 6.5.1. Symbolic File Access Modes Page 85 6.5.2. Octal File Access Modes Page 86 6.6. Chown and Chgrp—Change File Owner and Group Page 88 6.7. Mkdir and Rmdir—Create and Remove Directories Page 89 6.8. Find—Search for Files Page 90 6.9. Pack and Compress—Save Space Page 93 6.10. Tar—Collect Files Page 96 6.11. File—Deduce File Types Page 99 6.12. Du—Disk Usage Page 101 6.13. Od—Dump Files Page 102 7. What’s Going On Utilities Page 105 7.1. Date—Display the Date and Time Page 105 7.2. Who and Finger—List Logged-in Users Page 106 7.3. Passwd—Change Login Password Page 108 7.4. Ps—List Processes Page 109 7.5. Kill—Abort Background Processes Page 109 7.6. Nohup—Run Programs While Logged Off Page 111 7.7. Nice—Run Processes at Low Priority Page 112 7.8. Time—Time Processes Page 113 7.9. Echo—Repeat Command-line Arguments Page 114 7.10. Write and Talk—Communicating with Other Users Page 116 7.11. Stty and Tty—Your Terminal Handler Page 118 8. Text File Utilities Page 121 8.1. Cat—Type Files Page 122 8.2. Pr—Title and Paginate Files Page 124 8.3. Fmt—Justify Lines Page 127 8.4. Lp—Print Files Page 129 8.5. Pg—Browse Through a Text File Page 131 8.6. Wc—Count Lines, Words, and Characters Page 131 8.7. Diff—Compare Files Page 132 8.8. Sort—Order Files Page 137 8.9. Grep—Search for Text Patterns in Files Page 141 8.10. Cut and Paste—Rearrange Columns of Files Page 143 8.11. Tr—Translate Characters Page 145 8.12. Spell—Find Spelling Errors Page 147 8.13. Crypt—Encode Files Page 148 8.14. Tee—Duplicate Output Page 149 8.15. Head and Tail—Print the Beginning and End of a File Page 150 9. Basic Text Editing with Vi Page 154 9.1. UNIX Text Editors Page 155 9.2. Checking Your Terminal Type Page 156 9.3. Setting the Terminal Type Page 156 9.4. Starting Vi Page 157 9.5. Moving from Here to There Page 160 9.6. Adding and Inserting Text Page 162 9.7. Deleting Text Page 165 9.8. Managing Files Page 166 9.8.1. Saving Without Exiting Page 167 9.8.2. Quitting Without Saving Page 168 9.8.3. Editing a Different File Page 168 9.8.4. Adding One File to Another Page 169 9.9. Making Sense of Vi’s Command Syntax Page 169 10. Advanced Text Editing with Vi Page 171 10.1. Escaping to the Shell Page 171 10.2. Searching for Text Page 172 10.3. Fine-tuning Your Screen Display Page 175 10.4. More Ways to Modify Text Page 176 10.5. Selecting Your Preferences Page 178 10.6. Marking Text Page 179 10.7. Moving Blocks of Text Using Native Vi Commands Page 181 10.8. Moving Blocks of Text Aided by a Windowing System Page 183 10.9. Moving Text from One File to Another Using Native Vi Commands Page 184 10.10. Recovering Accidental Deletions Page 186 10.11. Filtering the Buffer Page 188 10.12. Vi Macros Page 190 10.12.1. Buffer Macros Page 190 10.12.2. Maps Page 192 10.12.3. Insert-mode Maps Page 194 10.12.4. Abbreviations Page 194 10.13. Line-editing Commands Page 195 10.14. Open-line Editing Page 195 11. The Bourne Shell Programming Language Page 197 11.1. Executing a Shell Program Page 198 11.2. Shell Variables Page 201 11.2.1. Read-only Shell Variables Page 202 11.2.2. Exporting Shell Variables Page 203 11.2.3. Using Shell Variables Interactively Page 204 11.2.4. Automatic Shell Variables Page 204 11.2.5. Standard Shell Variables Page 205 11.2.6. The Search Path Page 207 11.2.7. Handling Null and Unset Variables Page 209 11.3. Quoting Special Characters Page 210 11.4. Command Exit Status Page 212 11.5. Simple Conditionals Page 213 11.6. Simple Commands, Pipelines, Lists Page 214 11.7. The If Conditional Page 215 11.8. Shell Program Arguments Page 217 11.9. The While and Until Conditional Loops Page 220 11.10. Structured Commands Page 222 11.11. The For Statement Page 223 11.12. The Case Statement Page 224 11.13. Break and Continue Page 225 11.14. Command Substitution Page 226 11.15. Shell Substitutions Page 228 11.16. Here Documents Page 228 11.17. Shell Functions Page 230 11.18. Set—Display Variables and Specify Shell Operating Modes Page 232 11.19. Test—Evaluate Conditions Page 237 11.20. Expr—Evaluate Expressions Page 238 11.21. Ulimit—Set and Display Resource Limits Page 241 11.22. Getopts—Manage Options in Scripts Page 242 11.23. The Bourne Shell’s Built-in Commands Page 243 12. A Few Shell Programs Page 246 12.1. When Do You Use the Shell Programming Language? Page 246 12.2. How Many Users Are Logged In? Page 247 12.3. Listing Subdirectories Page 249 12.4. Listing Files in the Current Subtree Page 252 12.5. Using Eval to Reevaluate Command Lines Page 255 13. The AWK Programming Language Page 258 13.1. Simple Scripts Page 259 13.2. Flow of Control Statements Page 265 13.2.1. The If Statement Page 265 13.2.2. The While and Do Statements Page 267 13.2.3. The For Statement Page 269 13.3. AWK Patterns and Expressions Page 270 13.4. Arrays Page 271 13.5. Built-in Variables Page 274 13.6. Built-in Functions Page 276 13.7. Print and Printf Page 278 13.8. Perl: Successor to Awk Page 282 14. The Sed Text Editor Page 283 14.1. Text Modification Page 285 14.2. Control Flow Page 287 14.3. Input and Output Page 289 14.4. The Sed Hold Space Page 290 15. UNIX Platforms Page 292 15.1. System Evaluation Criteria Page 293 15.1.1. The Herd Mentality Page 293 15.1.2. Communicating with Your Peers Page 293 15.1.3. Application Software Page 294 15.1.4. Service, Support, and All That Page 294 15.1.5. Graphics Page 295 15.2. Performance Page 297 15.2.1. Integer Performance Page 298 15.2.2. Floating Point Performance Page 299 15.2.3. Graphics Performance Page 299 15.3. Common UNIX Platforms Page 300 15.3.1. Minicomputers Page 300 15.3.2. The Macintosh Page 300 15.3.3. PCs Page 301 15.3.4. Workstations Page 302 16. Window Systems Page 305 16.1. What Is a Window System? Page 306 16.2. Window Interfaces: Some Basic Concepts Page 306 16.3. Window Operations Page 308 16.4. Architecture of the X Window System Page 310 16.4.1. X Fits Well with “Open Systems” Idea Page 314 16.4.2. A Distributed Window System Page 315 16.4.3. The X Server and Display Connections Page 316 16.4.4. Applications, or X Clients Page 316 16.4.5. Window Managers Page 317 16.4.6. Compatibility: The ICCCM Page 317 16.5. Starting X Page 318 16.5.1. If the X Server Is Started for You Page 319 16.6. Customizing X Page 320 16.6.1. X Resources Page 321 16.6.2. Tools to Examine Resources Page 323 16.7. The X Display Page 324 16.7.1. Display Permissions Page 326 16.8. Window Manager Configuration Files Page 328 16.8.1. Motif Page 328 16.8.2. OPEN LOOK Page 331 16.8.3. Twm Specifics Page 332 16.9. Other Window Systems Page 334 16.10. Limitations of X Page 337 17. Networking Page 338 17.1. Uucp and IP Networking Overview Page 338 17.2. Terminology Page 340 17.3. The UUCP Family Page 342 17.4. Sending Mail Through UUCP Page 343 17.5. UUCP Administration Page 344 17.6. Cu and Tip Page 345 17.7. IP Networking Page 345 17.8. The Ethernet Page 347 17.9. How Ethernet Works Page 348 17.10. Other Hardware Technologies Page 349 17.11. Software Networking Protocols Page 349 17.12. Network Addressing Page 350 17.13. The Network Information Center Page 351 17.14. User-level Berkeley Networking Commands Page 354 17.15. Administration of Berkeley Networking Page 354 17.16. Network File Systems Page 356 17.17. NFS Administration Page 356 17.18. NFS and Automounting Page 359 17.19. Network Information Service Page 359 17.20. Networking the World: LANS, WANS, and Routers Page 361 17.21. Packets Page 362 17.22. Network Daemons Page 363 17.23. Booting over the Network Page 364 17.24. Networking UNIX with Other Kinds of Machines Page 365 18. LAN Networking Utilities Page 368 18.1. User-level Networking Commands Page 368 18.2. Connecting to Other Systems Page 369 18.2.1. Rlogin Page 370 18.2.2. Telnet Page 371 18.3. Executing Commands on Remote Systems—Rsh/Remsh Page 374 18.4. File Transfer Between Hosts Page 376 18.4.1. Remote Copy, Rcp Page 376 18.4.2. Ftp and Anonymous Ftp Page 377 18.5. What’s Going on on the Network? Page 383 18.5.1. Rwho Page 383 18.5.2. Ruptime Page 384 18.5.3. Rup Page 384 18.5.4. Ping Page 385 19. UUCP Networking Utilities Page 386 19.1. UUCP User-level Commands Page 386 19.2. Connecting to Other Systems Page 387 19.2.1. Cu, Call UNIX Page 387 19.2.2. Tip Page 391 19.3. File Transfer Between Hosts Page 393 19.3.1. UUCP Page 395 19.3.2. Uuto and Uupick Page 397 19.4. Executing Commands on Remote Systems—Uux Page 398 19.5. UUCP Status Commands Page 400 19.5.1. Uustat Page 400 19.5.2. Uulog Page 400 19.5.3. Uuname Page 401 20. System Management Page 402 20.1. The Superuser Page 403 20.2. System Configuration Page 404 20.2.1. Adding Device Drivers Page 405 20.2.2. Special Device Files Page 406 20.3. User Account Administration Page 406 20.3.1. The Passwd and Group Files Page 407 20.3.2. Login Name Page 408 20.3.3. User ID Page 408 20.3.4. Group ID Page 408 20.3.5. Initial Password Page 409 20.3.6. Home Directory Page 409 20.3.7. Login Shells and /etc/shells Page 409 20.3.8. Deleting a User Account Page 410 20.4. File Systems Page 411 20.4.1. Disk Partitions (Pre-SVR4) Page 412 20.4.2. Disk Slices (SVR4) Page 412 20.4.3. Building a File System Page 413 20.4.4. Mounting a File System Page 414 20.4.5. Unmounting a File System Page 416 20.4.6. Checking File System Consistency Page 417 20.4.7. The Root File System Page 418 20.4.8. Network File Systems Page 418 20.4.9. File System Tables Page 419 20.4.10. File System Types Page 419 20.5. Booting Page 420 20.5.1. Traditional Boot Process Page 420 20.5.2. SVR4 Booting and Init States Page 421 20.5.3. Shutting Down the System Page 421 20.6. Backups Page 422 20.6.1. Backup and Restore Basics Page 422 20.6.2. Backup Levels Page 422 20.6.3. Backup Schedule Page 423 20.6.4. Backup Media Page 424 20.6.5. Rotation of Media Page 425 20.7. Swapping and Sticky Mode Page 425 20.8. Setuid and Setgid Modes Page 426 20.9. Fifo Files Page 427 20.10. Links and Symbolic Links Page 428 20.11. Device Names Page 429 21. System Management Utilities Page 431 21.1. Su—Become Superuser Page 431 21.2. Mount and Unmount File Systems Page 432 21.2.1. Mount Page 432 21.2.2. Mountall Page 434 21.2.3. Umount, Umountall Page 434 21.3. Shutting Down the System Page 435 21.3.1. Sync—Synchronize Disk Information Page 435 21.3.2. Init Page 436 21.3.3. Shutdown Page 436 21.3.4. Halt Page 437 21.4. Mknod—Create Special Files Page 437 21.5. Backups Page 438 21.5.1. Ufsdump Page 438 21.5.2. Ufsrestore Page 438 21.5.3. Volcopy and Labelit Page 440 21.6. Newfs—Create a File System Page 441 21.7. Fsck—Check and Repair File Systems Page 442 21.8. Dd—Convert Files Page 443 21.9. Df—Disk Free Space Page 444 21.10. Cron, Crontab—Run Programs at Specified Times Page 444 22. Security Page 446 22.1. Data Protection Page 447 22.1.1. Irrecoverable Data Loss Page 447 22.1.2. Backup Security Page 448 22.2. Protection Against Intruders Page 448 22.2.1. Physical Security Page 449 22.2.2. Terminal Line Security Page 450 22.2.3. Telephone Access Page 450 22.3. Security Procedures and Education Page 451 22.3.1. Know Your System Page 451 22.3.2. The Human Dimension Page 452 22.3.3. The (Friendly) Cracker Page 452 22.4. Passwords and Accounts Page 453 22.4.1. Who Gets an Account Page 453 22.4.2. Basic Rules and Initial Password Page 454 22.4.3. How Passwords Work Page 454 22.4.4. How They Are Cracked Page 455 22.4.5. Password Filtering Page 455 22.4.6. Password Aging Page 456 22.4.7. Shadow Passwords Page 456 22.4.8. The Root Password Page 456 22.5. Superuser Precautions Page 457 22.6. Unix File Permissions and Security Page 458 22.6.1. Protection of System Directories Page 458 22.6.2. Setuid and Setgid Programs Page 459 22.7. Security of Installed Software Page 460 22.7.1. Outside Software Page 461 22.7.2. Viruses and Worms Page 462 22.7.3. Trojan Horse Programs Page 462 22.7.4. User-provided Security Holes Page 463 22.8. Security for the Individual User Page 463 22.8.1. E-mail Page 463 22.8.2. Protection of Files Page 464 22.8.3. Encryption Page 464 22.9. Network Security Considerations Page 465 22.10. Security Discussions Page 466 22.11. CERT—Computer Emergency Response Team Page 467 23. The UNIX System Kernel Page 468 23.1. Overview Page 469 23.2. Processes Page 470 23.2.1. The Process Table and the User Table Page 471 23.2.2. Sharing Program Text and Software Libraries Page 473 23.2.3. System Calls Page 473 23.2.4. User Mode and Kernel Mode Page 474 23.2.5. The Fork, Exec, and Wait System Calls Page 475 23.2.6. Handling Signals Page 478 23.2.7. Scheduling Processes Page 479 23.2.8. Swapping and Paging Page 480 23.2.9. Zombie Processes Page 482 23.3. Networking Page 482 23.4. Booting Page 484 23.4.1. The First Processes Page 485 23.4.2. The Init Process Page 486 23.5. The File System Page 487 23.5.1. Directories Page 490 23.5.2. I-nodes Page 492 23.5.3. The File Table Page 494 23.5.4. Pipes Page 495 23.5.5. Network File Systems Page 495 23.6. Device Drivers Page 496 23.6.1. Special Device Files and the Cdevsw and Bdevsw Tables Page 497 23.6.2. Interrupts Page 500 23.6.3. Traditional Character Handling Page 500 23.6.4. Process Groups Page 502 23.7. Communication Extensions Page 502 23.7.1. Sockets Page 502 23.7.2. Streams Page 503 I. Vi Visual Command Reference Page 505 II. Vi Options Reference Page 517 III. Ex Command Reference Page 522 Index. Page 541