Advanced Bash−Scripting Guide

More documents

Recommendations

Info

Advanced Bash−Scripting Guide then # the corresponding process exists. echo "Process #$1 invoked by $exe_file." else echo "No such process running." fi # This elaborate script can *almost* be replaced by # ps ax | grep $1 | awk '{ print $5 }' # However, this will not work... # because the fifth field of 'ps' is argv[0] of the process, # not the executable file path. # # However, either of the following would work. # find /proc/$1/exe −printf '%l\n' # lsof −aFn −p $1 −d txt | sed −ne 's/^n//p' # Additional commentary by Stephane Chazelas. exit 0 Example 28−2. On−line connect status #!/bin/bash PROCNAME=pppd # ppp daemon PROCFILENAME=status # Where to look. NOTCONNECTED=65 INTERVAL=2 # Update every 2 seconds. pidno=$( ps ax | grep −v "ps ax" | grep −v grep | grep $PROCNAME | awk '{ print $1 }' ) # Finding the process number of 'pppd', the 'ppp daemon'. # Have to filter out the process lines generated by the search itself. # # However, as Oleg Philon points out, #+ this could have been considerably simplified by using "pidof". # pidno=$( pidof $PROCNAME ) # # Moral of the story: #+ When a command sequence gets too complex, look for a shortcut. if [ −z "$pidno" ] # If no pid, then process is not running. then echo "Not connected." exit $NOTCONNECTED else echo "Connected."; echo fi while [ true ] do # Endless loop, script can be improved here. if [ ! −e "/proc/$pidno/$PROCFILENAME" ] # While process running, then "status" file exists. then echo "Disconnected." exit $NOTCONNECTED fi Chapter 28. /dev and /proc 314
Advanced Bash−Scripting Guide netstat −s | grep "packets received" # Get some connect statistics. netstat −s | grep "packets delivered" sleep $INTERVAL echo; echo done exit 0 # As it stands, this script must be terminated with a Control−C. # Exercises: # −−−−−−−−− # Improve the script so it exits on a "q" keystroke. # Make the script more user−friendly in other ways. In general, it is dangerous to write to the files in /proc, as this can corrupt the filesystem or crash the machine. Chapter 28. /dev and /proc 315
Page 1 and 2:
Advanced Bash−Scripting Guide An
Page 3 and 4:
Advanced Bash−Scripting Guide Tab
Page 5 and 6:
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 31 and 32:
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 41 and 42:
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:
Page 61 and 62:
Chapter 8. Operations and Related T
Page 63 and 64:
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:
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:
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:
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:
Advanced Bash−Scripting Guide # T
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:
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: Advanced Bash−Scripting Guide fi
Page 277 and 278: Advanced Bash−Scripting Guide ech
Page 279 and 280: Advanced Bash−Scripting Guide exe
Page 281 and 282: Advanced Bash−Scripting Guide f1
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 295 and 296: Chapter 25. List Constructs The "an
Page 297 and 298: # AND LIST executes on true, OR LIS
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 309 and 310: fi let "t += $i " Primes[t]=$NON_PR
Page 311 and 312: Advanced Bash−Scripting Guide # =
Page 313 and 314: Advanced Bash−Scripting Guide Exa
Page 315 and 316: # −−−−−−−−− # 1)
Page 317 and 318: Chapter 28. /dev and /proc A Linux
Page 319: Advanced Bash−Scripting Guide Exa
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: Advanced Bash−Scripting Guide exi
Page 347 and 348: Advanced Bash−Scripting Guide # T
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: Advanced Bash−Scripting Guide fi
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:
Advanced Bash−Scripting Guide fi
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?