Advanced Bash−Scripting Guide

More documents

Recommendations

Info

Advanced Bash−Scripting Guide Table of Contents Chapter 10. Loops and Branches 10.4. Testing and Branching................................................................................................................117 Chapter 11. Internal Commands and Builtins.............................................................................................124 11.1. Job Control Commands..............................................................................................................144 Chapter 12. External Filters, Programs and Commands...........................................................................148 12.1. Basic Commands........................................................................................................................148 12.2. Complex Commands...................................................................................................................151 12.3. Time / Date Commands..............................................................................................................158 12.4. Text Processing Commands........................................................................................................160 12.5. File and Archiving Commands...................................................................................................176 12.6. Communications Commands......................................................................................................191 12.7. Terminal Control Commands.....................................................................................................195 12.8. Math Commands.........................................................................................................................196 12.9. Miscellaneous Commands..........................................................................................................204 Chapter 13. System and Administrative Commands..................................................................................214 Chapter 14. Command Substitution.............................................................................................................236 Chapter 15. Arithmetic Expansion................................................................................................................241 Chapter 16. I/O Redirection...........................................................................................................................242 16.1. Using exec...................................................................................................................................244 16.2. Redirecting Code Blocks............................................................................................................247 16.3. Applications................................................................................................................................251 Chapter 17. Here Documents.........................................................................................................................253 Chapter 18. Recess Time................................................................................................................................260 Part 4. Advanced Topics.................................................................................................................................261 Chapter 19. Regular Expressions..................................................................................................................262 19.1. A Brief Introduction to Regular Expressions..............................................................................262 19.2. Globbing.....................................................................................................................................265 Chapter 20. Subshells.....................................................................................................................................267 Chapter 21. Restricted Shells.........................................................................................................................270 Chapter 22. Process Substitution...................................................................................................................272 Chapter 23. Functions....................................................................................................................................274 23.1. Complex Functions and Function Complexities.........................................................................276 23.2. Local Variables...........................................................................................................................283 23.2.1. Local variables make recursion possible..........................................................................284 ii
Advanced Bash−Scripting Guide Table of Contents Chapter 24. Aliases.........................................................................................................................................286 Chapter 25. List Constructs...........................................................................................................................289 Chapter 26. Arrays.........................................................................................................................................292 Chapter 27. Files.............................................................................................................................................310 Chapter 28. /dev and /proc.............................................................................................................................311 28.1. /dev..............................................................................................................................................311 28.2. /proc............................................................................................................................................311 Chapter 29. Of Zeros and Nulls.....................................................................................................................316 Chapter 30. Debugging...................................................................................................................................319 Chapter 31. Options........................................................................................................................................325 Chapter 32. Gotchas.......................................................................................................................................327 Chapter 33. Scripting With Style..................................................................................................................333 33.1. Unofficial Shell Scripting Stylesheet..........................................................................................333 Chapter 34. Miscellany...................................................................................................................................336 34.1. Interactive and non−interactive shells and scripts......................................................................336 34.2. Shell Wrappers............................................................................................................................337 34.3. Tests and Comparisons: Alternatives..........................................................................................340 34.4. Recursion....................................................................................................................................341 34.5. "Colorizing" Scripts....................................................................................................................342 34.6. Optimizations..............................................................................................................................346 34.7. Assorted Tips..............................................................................................................................347 34.8. Security Issues............................................................................................................................354 34.9. Portability Issues.........................................................................................................................354 34.10. Shell Scripting Under Windows...............................................................................................354 Chapter 35. Bash, version 2...........................................................................................................................355 Chapter 36. Endnotes.....................................................................................................................................360 36.1. Author's Note..............................................................................................................................360 36.2. About the Author........................................................................................................................360 36.3. Tools Used to Produce This Book..............................................................................................360 36.3.1. Hardware...........................................................................................................................360 36.3.2. Software and Printware.....................................................................................................360 36.4. Credits.........................................................................................................................................361 Bibliography....................................................................................................................................................363 iii
Page 1 and 2: Advanced Bash−Scripting Guide An
Page 3: Advanced Bash−Scripting Guide Tab
Page 7 and 8: Chapter 1. Why Shell Programming? A
Page 9 and 10: Chapter 2. Starting Off With a Sha
Page 11 and 12: Advanced Bash−Scripting Guide Eac
Page 13 and 14: Chapter 3. Special Characters Speci
Page 15 and 16: Advanced Bash−Scripting Guide \ /
Page 17 and 18: Advanced Bash−Scripting Guide * ?
Page 19 and 20: Advanced Bash−Scripting Guide ech
Page 21 and 22: Advanced Bash−Scripting Guide ASC
Page 23 and 24: # Sometimes, though, you get: # 11
Page 25 and 26: The "−" can be used to pipe stdou
Page 27 and 28: change the behavior of the terminal
Page 29 and 30: Chapter 4. Introduction to Variable
Page 33 and 34: Advanced Bash−Scripting Guide Exa
Page 35 and 36: Advanced Bash−Scripting Guide MIN
Page 37 and 38: The shift command reassigns the pos
Page 39 and 40: Example 5−1. Echoing Weird Variab
Page 43 and 44: (cd /source/directory && tar cf −
Page 45 and 46: true # the "true" builtin. echo "ex
Page 47 and 48: Advanced Bash−Scripting Guide Thi
Page 49 and 50: Advanced Bash−Scripting Guide if
Page 51 and 52: if [[ −e $file ]] then echo "Pass
Page 53 and 54: Advanced Bash−Scripting Guide −
Page 55 and 56:
7.3. Comparison operators (binary)
Page 57 and 58:
Example 7−5. arithmetic and strin
Page 59 and 60:
Advanced Bash−Scripting Guide Exa
Page 61 and 62:
Chapter 8. Operations and Related T
Page 63 and 64:
Advanced Bash−Scripting Guide ech
Page 65 and 66:
Advanced Bash−Scripting Guide ! ^
Page 67 and 68:
Advanced Bash−Scripting Guide let
Page 69 and 70:
Part 3. Beyond the Basics Table of
Page 71 and 72:
$EDITOR the default editor invoked
Page 73 and 74:
Advanced Bash−Scripting Guide (Th
Page 75 and 76:
Advanced Bash−Scripting Guide #!/
Page 77 and 78:
Example 9−2. Timed Input Advanced
Page 79 and 80:
Advanced Bash−Scripting Guide fi
Page 81 and 82:
Page 83 and 84:
echo 'IFS=":", using "$@"' c=0 for
Page 85 and 86:
Page 87 and 88:
Page 89 and 90:
Advanced Bash−Scripting Guide #+
Page 91 and 92:
Advanced Bash−Scripting Guide use
Page 93 and 94:
Page 95 and 96:
echo '${var1#$pattern1} =' "${var1#
Page 97 and 98:
t=${path_name%/*.*} # Same effect a
Page 99 and 100:
Advanced Bash−Scripting Guide The
Page 101 and 102:
Advanced Bash−Scripting Guide exi
Page 103 and 104:
Advanced Bash−Scripting Guide don
Page 105 and 106:
Advanced Bash−Scripting Guide thr
Page 107 and 108:
Advanced Bash−Scripting Guide cou
Page 109 and 110:
Chapter 10. Loops and Branches Oper
Page 111 and 112:
Advanced Bash−Scripting Guide if
Page 113 and 114:
Advanced Bash−Scripting Guide # T
Page 115 and 116:
Advanced Bash−Scripting Guide OUT
Page 117 and 118:
As is the case with for/in loops, p
Page 119 and 120:
This construct tests for a conditio
Page 121 and 122:
Advanced Bash−Scripting Guide ###
Page 123 and 124:
Page 125 and 126:
# Accept upper or lowercase input.
Page 127 and 128:
Page 129 and 130:
Page 131 and 132:
Advanced Bash−Scripting Guide a=`
Page 133 and 134:
Page 135 and 136:
# May need to also press ENTER if a
Page 137 and 138:
Page 139 and 140:
Page 141 and 142:
Page 143 and 144:
Page 145 and 146:
Page 147 and 148:
Advanced Bash−Scripting Guide ret
Page 149 and 150:
Advanced Bash−Scripting Guide Com
Page 151 and 152:
Advanced Bash−Scripting Guide if
Page 153 and 154:
Advanced Bash−Scripting Guide ena
Page 155 and 156:
cat, tac # Burn the CDR. cdrecord
Page 157 and 158:
Advanced Bash−Scripting Guide 12.
Page 159 and 160:
exit $E_CHANGED_MIND ;; *) echo "De
Page 161 and 162:
The multiplication operator must be
Page 163 and 164:
echo Number of digits at the beginn
Page 165 and 166:
Outputs very verbose timing statist
Page 167 and 168:
This line occurs three times. This
Page 169 and 170:
# List all the users in /etc/passwd
Page 171 and 172:
Advanced Bash−Scripting Guide # r
Page 173 and 174:
Advanced Bash−Scripting Guide gre
Page 175 and 176:
Page 177 and 178:
The −d option deletes a range of
Page 179 and 180:
# Delete CR and write to new file.
Page 183 and 184:
Advanced Bash−Scripting Guide Thi
Page 185 and 186:
Advanced Bash−Scripting Guide gzi
Page 187 and 188:
Advanced Bash−Scripting Guide # S
Page 189 and 190:
Page 191 and 192:
Advanced Bash−Scripting Guide pre
Page 193 and 194:
Page 195 and 196:
Advanced Bash−Scripting Guide che
Page 197 and 198:
Advanced Bash−Scripting Guide fil
Page 199 and 200:
Advanced Bash−Scripting Guide No
Page 201 and 202:
mailto Similar to the mail command,
Page 203 and 204:
Advanced Bash−Scripting Guide int
Page 205 and 206:
Advanced Bash−Scripting Guide cas
Page 207 and 208:
Page 209 and 210:
Advanced Bash−Scripting Guide Mos
Page 211 and 212:
Advanced Bash−Scripting Guide 2 3
Page 213 and 214:
Page 215 and 216:
Advanced Bash−Scripting Guide To
Page 217 and 218:
Page 219 and 220:
Advanced Bash−Scripting Guide m4
Page 221 and 222:
Advanced Bash−Scripting Guide who
Page 223 and 224:
Advanced Bash−Scripting Guide Ech
Page 225 and 226:
Page 227 and 228:
Advanced Bash−Scripting Guide car
Page 229 and 230:
Advanced Bash−Scripting Guide net
Page 231 and 232:
Advanced Bash−Scripting Guide pst
Page 233 and 234:
[ ${NETWORKING} = "no" ] && exit 0
Page 235 and 236:
Page 237 and 238:
chroot Advanced Bash−Scripting Gu
Page 239 and 240:
Advanced Bash−Scripting Guide bas
Page 241 and 242:
Page 243 and 244:
Advanced Bash−Scripting Guide ' c
Page 245 and 246:
Advanced Bash−Scripting Guide Not
Page 247 and 248:
Chapter 15. Arithmetic Expansion Ar
Page 249 and 250:
Page 251 and 252:
# Saves stdin. Advanced Bash−Scri
Page 253 and 254:
Page 255 and 256:
Page 257 and 258:
Advanced Bash−Scripting Guide 16.
Page 259 and 260:
Chapter 17. Here Documents A here d
Page 261 and 262:
Advanced Bash−Scripting Guide Thi
Page 263 and 264:
Advanced Bash−Scripting Guide Fil
Page 265 and 266:
Example 17−11. A self−documenti
Page 267 and 268:
Part 4. Advanced Topics At this poi
Page 269 and 270:
Advanced Bash−Scripting Guide lit
Page 271 and 272:
"Sed & Awk", by Dougherty and Robbi
Page 273 and 274:
Chapter 20. Subshells Running a she
Page 275 and 276:
Page 277 and 278:
Page 279 and 280:
Advanced Bash−Scripting Guide exe
Page 281 and 282:
Advanced Bash−Scripting Guide f1
Page 283 and 284:
Page 285 and 286:
# Range: 0 − 200 # It's crude, bu
Page 287 and 288:
Advanced Bash−Scripting Guide alt
Page 289 and 290:
# grep PATTERN /etc/passwd | awk
Page 291 and 292:
Advanced Bash−Scripting Guide # Y
Page 293 and 294:
Page 295 and 296:
Chapter 25. List Constructs The "an
Page 297 and 298:
# AND LIST executes on true, OR LIS
Page 299 and 300:
Page 301 and 302:
echo ${colors[$index]} let "index =
Page 303 and 304:
# Replace all matching wildcarded s
Page 305 and 306:
Advanced Bash−Scripting Guide Cop
Page 307 and 308:
Page 309 and 310:
fi let "t += $i " Primes[t]=$NON_PR
Page 311 and 312:
Advanced Bash−Scripting Guide # =
Page 313 and 314:
Page 315 and 316:
# −−−−−−−−− # 1)
Page 317 and 318:
Chapter 28. /dev and /proc A Linux
Page 319 and 320:
Page 321 and 322:
Advanced Bash−Scripting Guide net
Page 323 and 324:
Advanced Bash−Scripting Guide # A
Page 325 and 326:
Chapter 30. Debugging The Bash shel
Page 327 and 328:
4. Advanced Bash−Scripting Guide
Page 329 and 330:
Advanced Bash−Scripting Guide whi
Page 331 and 332:
Chapter 31. Options Options are set
Page 333 and 334:
Chapter 32. Gotchas Turandot: Gli e
Page 335 and 336:
command1 2> − | command2 # Trying
Page 337 and 338:
echo "one two three" | read a b c #
Page 339 and 340:
Chapter 33. Scripting With Style Ge
Page 341 and 342:
Advanced Bash−Scripting Guide See
Page 343 and 344:
Advanced Bash−Scripting Guide # i
Page 345 and 346:
Page 347 and 348:
Page 349 and 350:
Advanced Bash−Scripting Guide tpu
Page 351 and 352:
#!/bin/bash # color−echo.sh: Echo
Page 353 and 354:
34.7. Assorted Tips Advanced Bash
Page 355 and 356:
Advanced Bash−Scripting Guide the
Page 357 and 358:
Advanced Bash−Scripting Guide •
Page 359 and 360:
# agram.sh: Playing games with anag
Page 361 and 362:
Chapter 35. Bash, version 2 The cur
Page 363 and 364:
Advanced Bash−Scripting Guide # R
Page 365 and 366:
Page 367 and 368:
1−56592−580−7). This is the s
Page 369 and 370:
Bibliography Edited by Peter Dennin
Page 371 and 372:
Advanced Bash−Scripting Guide * A
Page 373 and 374:
Mark Komarinski's Printing−Usage
Page 375 and 376:
Advanced Bash−Scripting Guide els
Page 377 and 378:
Page 379 and 380:
Advanced Bash−Scripting Guide #+
Page 381 and 382:
Page 383 and 384:
Advanced Bash−Scripting Guide gre
Page 385 and 386:
Advanced Bash−Scripting Guide pad
Page 387 and 388:
Advanced Bash−Scripting Guide arr
Page 389 and 390:
let "row = $r" # Count center row o
Page 391 and 392:
next_gen "$Cur" let "generation +=
Page 393 and 394:
[−c localdirectory] [−m filepat
Page 395 and 396:
Advanced Bash−Scripting Guide # =
Page 397 and 398:
Advanced Bash−Scripting Guide } z
Page 399 and 400:
Advanced Bash−Scripting Guide } e
Page 401 and 402:
Advanced Bash−Scripting Guide #:d
Page 403 and 404:
# ListDirectory "FileGlob" "Field
Page 405 and 406:
Advanced Bash−Scripting Guide # I
Page 407 and 408:
The md5sum program is documented as
Page 409 and 410:
Note: 'mount −l' does return the
Page 411 and 412:
Advanced Bash−Scripting Guide dec
Page 413 and 414:
Appendix B. A Sed and Awk Micro−P
Page 415 and 416:
Advanced Bash−Scripting Guide /GU
Page 417 and 418:
Advanced Bash−Scripting Guide Tha
Page 419 and 420:
Appendix D. A Detailed Introduction
Page 421 and 422:
Appendix E. Localization Localizati
Page 423 and 424:
Appendix F. History Commands The Ba
Page 425 and 426:
Advanced Bash−Scripting Guide } X
Page 427 and 428:
Advanced Bash−Scripting Guide pow
Page 429 and 430:
Advanced Bash−Scripting Guide *)
Page 431 and 432:
Page 433 and 434:
Advanced Bash−Scripting Guide com
Page 435 and 436:
Appendix H. Converting DOS Batch Fi
Page 437 and 438:
Advanced Bash−Scripting Guide XCO
Page 439 and 440:
Appendix I. Exercises I.1. Analyzin
Page 441 and 442:
Lottery Numbers One type of lottery
Page 443 and 444:
Advanced Bash−Scripting Guide Usi
Page 445 and 446:
Advanced Bash−Scripting Guide and
Page 447 and 448:
Page 449 and 450:
[33] This is actually a script adap
Page 451 and 452:
# Thanks to Stephane Chazelas for p
show all

Advanced Bash−Scripting Guide

Create successful ePaper yourself

Delete template?

Save as template?