examples/obashdb/bashdb

   1 #! /bin/bash
   2 # bashdb - Bash shell debugger
   3 #
   4 # Adapted from an idea in O'Reilly's `Learning the Korn Shell'
   5 # Copyright (C) 1993-1994 O'Reilly and Associates, Inc.
   6 # Copyright (C) 1998, 1999, 2001 Gary V. Vaughan <gvv@techie.com>>
   7 #
   8 # This program is free software; you can redistribute it and/or modify
   9 # it under the terms of the GNU General Public License as published by
  10 # the Free Software Foundation; either version 2 of the License, or
  11 # (at your option) any later version.
  12 #
  13 # This program is distributed in the hope that it will be useful, but
  14 # WITHOUT ANY WARRANTY; without even the implied warranty of
  15 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16 # General Public License for more details.
  17 #
  18 # You should have received a copy of the GNU General Public License
  19 # along with this program; if not, write to the Free Software
  20 # Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  21 #
  22 # As a special exception to the GNU General Public License, if you
  23 # distribute this file as part of a program that contains a
  24 # configuration script generated by Autoconf, you may include it under
  25 # the same distribution terms that you use for the rest of that program.
  26
  27 # NOTE:
  28 #
  29 # This program requires bash 2.x.
  30 # If bash 2.x is installed as "bash2", you can invoke  bashdb like this:
  31 #
  32 #   DEBUG_SHELL=/bin/bash2 /bin/bash2 bashdb script.sh
  33
  34 # TODO:
  35 #
  36 # break [regexp]
  37 # cond [break] [condition]
  38 # tbreak [regexp|+lines]
  39 # restart
  40 # Variable watchpoints
  41 # Instrument `source' and `.' files in $_potbelliedpig
  42 # be cleverer about lines we allow breakpoints to be set on
  43 # break [function_name]
  44
  45 echo 'Bash Debugger version 1.2.4'
  46
  47 export _dbname=${0##*/}
  48
  49 if test $# -lt 1; then
  50   echo "$_dbname: Usage: $_dbname filename" >&2
  51   exit 1
  52 fi
  53
  54 _guineapig=$1
  55
  56 if test ! -r $1; then
  57   echo "$_dbname: Cannot read file '$_guineapig'." >&2
  58   exit 1
  59 fi
  60
  61 shift
  62
  63 __debug=${TMPDIR-/tmp}/bashdb.$$
  64 sed -e '/^# bashdb - Bash shell debugger/,/^# -- DO NOT DELETE THIS LINE -- /d' "$0" > $__debug
  65 cat $_guineapig >> $__debug
  66 exec ${DEBUG_SHELL-bash} $__debug $_guineapig "$@"
  67
  68 exit 1
  69
  70 # -- DO NOT DELETE THIS LINE -- The program depends on it
  71
  72 #bashdb preamble
  73 # $1 name of the original guinea pig script
  74
  75 __debug=$0
  76 _guineapig=$1
  77 __steptrap_calls=0
  78
  79 shift
  80
  81 shopt -s extglob        # turn on extglob so we can parse the debugger funcs
  82
  83 function _steptrap
  84 {
  85   local i=0
  86
  87   _curline=$1
  88
  89   if (( ++__steptrap_calls > 1 && $_curline == 1 )); then
  90     return
  91   fi
  92
  93   if [ -n "$_disps" ]; then
  94     while (( $i < ${#_disps[@]} ))
  95     do
  96       if [ -n "${_disps[$i]}" ]; then
  97         _msg "${_disps[$i]}: \c"
  98         eval _msg ${_disps[$i]}
  99       fi
 100       let i=$i+1
 101     done
 102   fi
 103
 104   if (( $_trace )); then
 105     _showline $_curline
 106   fi
 107
 108   if (( $_steps >= 0 )); then
 109     let _steps="$_steps - 1"
 110   fi
 111
 112   if _at_linenumbp ; then
 113     _msg "Reached breakpoint at line $_curline"
 114     _showline $_curline
 115     _cmdloop
 116   elif [ -n "$_brcond" ] && eval $_brcond; then
 117     _msg "Break condition $_brcond true at line $_curline"
 118     _showline $_curline
 119     _cmdloop
 120   elif (( $_steps == 0 )); then
 121     # Assuming a real script will have the "#! /bin/sh" at line 1,
 122     # assume that when $_curline == 1 we are inside backticks.
 123     if (( ! $_trace )); then
 124       _msg "Stopped at line $_curline"
 125       _showline $_curline
 126     fi
 127     _cmdloop
 128   fi
 129 }
 130
 131 function _setbp
 132 {
 133   local i f line _x
 134
 135   if [ -z "$1" ]; then
 136     _listbp
 137     return
 138   fi
 139
 140   eval "$_seteglob"
 141
 142   if [[ $1 == *(\+)[1-9]*([0-9]) ]]; then
 143     case $1 in
 144     +*)
 145       # normalize argument, then double it (+2 -> +2 + 2 = 4)
 146       _x=${1##*([!1-9])}        # cut off non-numeric prefix
 147       _x=${x%%*([!0-9])}        # cut off non-numeric suffix
 148       f=$(( $1 + $_x ))
 149       ;;
 150     *)
 151       f=$(( $1 ))
 152       ;;
 153     esac
 154
 155     # find the next valid line
 156     line="${_lines[$f]}"
 157     while _invalidbreakp $f
 158     do
 159       (( f++ ))
 160       line="${_lines[$f]}"
 161     done
 162
 163     if (( $f != $1 ))
 164     then
 165       _msg "Line $1 is not a valid breakpoint"
 166     fi
 167
 168     if [ -n "${_lines[$f]}" ]; then
 169       _linebp[$1]=$1;
 170       _msg "Breakpoint set at line $f"
 171     else
 172       _msg "Breakpoints can only be set on executable lines"
 173     fi
 174   else
 175     _msg "Please specify a numeric line number"
 176   fi
 177
 178   eval "$_resteglob"
 179 }
 180
 181 function _listbp
 182 {
 183   local i
 184
 185   if [ -n "$_linebp" ]; then
 186     _msg "Breakpoints:"
 187     for i in ${_linebp[*]}; do
 188       _showline $i
 189     done
 190   else
 191     _msg "No breakpoints have been set"
 192   fi
 193 }
 194
 195 function _clearbp
 196 {
 197   local i
 198
 199   if [ -z "$1" ]; then
 200     read -e -p "Delete all breakpoints? "
 201     case $REPLY in
 202     [yY]*)
 203       unset _linebp[*]
 204       _msg "All breakpoints have been cleared"
 205       ;;
 206     esac
 207     return 0
 208   fi
 209
 210   eval "$_seteglob"
 211
 212   if [[ $1 == [1-9]*([0-9]) ]]; then
 213     unset _linebp[$1]
 214     _msg "Breakpoint cleared at line $1"
 215   else
 216     _msg "Please specify a numeric line number"
 217   fi
 218
 219   eval "$_resteglob"
 220 }
 221
 222 function _setbc
 223 {
 224   if (( $# > 0 )); then
 225     _brcond=$@
 226     _msg "Break when true: $_brcond"
 227   else
 228     _brcond=
 229     _msg "Break condition cleared"
 230   fi
 231 }
 232
 233 function _setdisp
 234 {
 235   if [ -z "$1" ]; then
 236     _listdisp
 237   else
 238     _disps[${#_disps[@]}]="$1"
 239     if (( ${#_disps[@]} < 10 ))
 240     then
 241       _msg " ${#_disps[@]}: $1"
 242     else
 243       _msg "${#_disps[@]}: $1"
 244     fi
 245   fi
 246 }
 247
 248 function _listdisp
 249 {
 250   local i=0 j
 251
 252   if [ -n "$_disps" ]; then
 253     while (( $i < ${#_disps[@]} ))
 254     do
 255       let j=$i+1
 256     if (( ${#_disps[@]} < 10 ))
 257     then
 258       _msg " $j: ${_disps[$i]}"
 259     else
 260       _msg "$j: ${_disps[$i]}"
 261     fi
 262       let i=$j
 263     done
 264   else
 265     _msg "No displays have been set"
 266   fi
 267 }
 268
 269 function _cleardisp
 270 {
 271   if (( $# < 1 )) ; then
 272     read -e -p "Delete all display expressions? "
 273     case $REPLY in
 274     [Yy]*)
 275       unset _disps[*]
 276       _msg "All breakpoints have been cleared"
 277       ;;
 278     esac
 279     return 0
 280   fi
 281
 282   eval "$_seteglob"
 283
 284   if [[ $1 == [1-9]*([0-9]) ]]; then
 285     unset _disps[$1]
 286     _msg "Display $i has been cleared"
 287   else
 288     _listdisp
 289     _msg "Please specify a numeric display number"
 290   fi
 291
 292   eval "$_resteglob"
 293 }
 294
 295 # usage _ftrace -u funcname [funcname...]
 296 function _ftrace
 297 {
 298   local _opt=-t _tmsg="enabled" _func
 299   if [[ $1 == -u ]]; then
 300         _opt=+t
 301         _tmsg="disabled"
 302         shift
 303   fi
 304   for _func; do
 305           declare -f $_opt $_func
 306           _msg "Tracing $_tmsg for function $_func"
 307   done
 308 }
 309
 310 function _cmdloop
 311 {
 312   local cmd args
 313
 314   while read -e -p "bashdb> " cmd args; do
 315     test -n "$cmd" && history -s "$cmd $args"   # save on history list
 316     test -n "$cmd" || { set $_lastcmd; cmd=$1; shift; args=$*; }
 317     if [ -n "$cmd" ]
 318     then
 319       case $cmd in
 320         b|br|bre|brea|break)
 321           _setbp $args
 322           _lastcmd="break $args"
 323           ;;
 324         co|con)
 325           _msg "ambiguous command: '$cmd', condition, continue?"
 326           ;;
 327         cond|condi|condit|conditi|conditio|condition)
 328           _setbc $args
 329           _lastcmd="condition $args"
 330           ;;
 331         c|cont|conti|contin|continu|continue)
 332           _lastcmd="continue"
 333           return
 334           ;;
 335         d)
 336           _msg "ambiguous command: '$cmd', delete, display?"
 337           ;;
 338         de|del|dele|delet|delete)
 339           _clearbp $args
 340           _lastcmd="delete $args"
 341           ;;
 342         di|dis|disp|displ|displa|display)
 343           _setdisp $args
 344           _lastcmd="display $args"
 345           ;;
 346         f|ft|ftr|ftra|ftrace)
 347           _ftrace $args
 348           _lastcmd="ftrace $args"
 349           ;;
 350         \?|h|he|hel|help)
 351           _menu
 352           _lastcmd="help"
 353           ;;
 354         l|li|lis|list)
 355           _displayscript $args
 356           # _lastcmd is set in the _displayscript function
 357           ;;
 358         p|pr|pri|prin|print)
 359           _examine $args
 360           _lastcmd="print $args"
 361           ;;
 362         q|qu|qui|quit)
 363           exit
 364           ;;
 365         s|st|ste|step|n|ne|nex|next)
 366           let _steps=${args:-1}
 367           _lastcmd="next $args"
 368           return
 369           ;;
 370         t|tr|tra|trac|trace)
 371           _xtrace
 372           ;;
 373         u|un|und|undi|undis|undisp|undispl|undispla|undisplay)
 374           _cleardisp $args
 375           _lastcmd="undisplay $args"
 376           ;;
 377         !*)
 378           eval ${cmd#!} $args
 379           _lastcmd="$cmd $args"
 380           ;;
 381         *)
 382           _msg "Invalid command: '$cmd'"
 383           ;;
 384       esac
 385     fi
 386   done
 387 }
 388
 389 function _at_linenumbp
 390 {
 391   [[ -n ${_linebp[$_curline]} ]]
 392 }
 393
 394 function _invalidbreakp
 395 {
 396   local line=${_lines[$1]}
 397
 398   # XXX - should use shell patterns
 399   if test -z "$line" \
 400       || expr "$line" : '[ \t]*#.*' > /dev/null \
 401       || expr "$line" : '[ \t]*;;[ \t]*$' > /dev/null \
 402       || expr "$line" : '[ \t]*[^)]*)[ \t]*$' > /dev/null \
 403       || expr "$line" : '[ \t]*;;[ \t]*#.**$' > /dev/null \
 404       || expr "$line" : '[ \t]*[^)]*)[ \t]*;;[ \t]*$' > /dev/null \
 405       || expr "$line" : '[ \t]*[^)]*)[ \t]*;;*[ \t]*#.*$' > /dev/null
 406   then
 407     return 0
 408   fi
 409
 410   return 1
 411 }
 412
 413 function _examine
 414 {
 415   if [ -n "$*" ]; then
 416     _msg "$args: \c"
 417     eval _msg $args
 418   else
 419     _msg "Nothing to print"
 420   fi
 421 }
 422
 423 function _displayscript
 424 {
 425   local i j start end bp cl
 426
 427   if (( $# == 1 )); then        # list 5 lines on either side of $1
 428     if [ $1 = "%" ]; then
 429       let start=1
 430       let end=${#_lines[@]}
 431     else
 432       let start=$1-5
 433       let end=$1+5
 434     fi
 435   elif (( $# > 1 )); then       # list between start and end
 436     if [ $1 = "^" ]; then
 437       let start=1
 438     else
 439       let start=$1
 440     fi
 441
 442     if [ $2 = "\$" ]; then
 443       let end=${#_lines[@]}
 444     else
 445       let end=$2
 446     fi
 447   else                          # list 5 lines on either side of current line
 448     let start=$_curline-5
 449     let end=$_curline+5
 450   fi
 451
 452   # normalize start and end
 453   if (( $start < 1 )); then
 454     start=1
 455   fi
 456   if (( $end > ${#_lines[@]} )); then
 457     end=${#_lines[@]}
 458   fi
 459
 460   cl=$(( $end - $start ))
 461   if (( $cl > ${LINES-24} )); then
 462     pager=${PAGER-more}
 463   else
 464     pager=cat
 465   fi
 466
 467   i=$start
 468   ( while (( $i <= $end )); do
 469       _showline $i
 470       let i=$i+1
 471     done ) 2>&1 | $pager
 472
 473   # calculate the next block of lines
 474   start=$(( $end + 1 ))
 475   end=$(( $start + 11 ))
 476   if (( $end > ${#_lines[@]} ))
 477   then
 478     end=${#_lines[@]}
 479   fi
 480
 481   _lastcmd="list $start $end"
 482 }
 483
 484 function _xtrace
 485 {
 486   let _trace="! $_trace"
 487   if (( $_trace )); then
 488     _msg "Execution trace on"
 489   else
 490     _msg "Execution trace off"
 491   fi
 492 }
 493
 494 function _msg
 495 {
 496   echo -e "$@" >&2
 497 }
 498
 499 function _showline
 500 {
 501   local i=0 bp=' ' line=$1 cl=' '
 502
 503   if [[ -n ${_linebp[$line]} ]]; then
 504     bp='*'
 505   fi
 506
 507   if  (( $_curline == $line )); then
 508     cl=">"
 509   fi
 510
 511   if (( $line < 100 )); then
 512     _msg "${_guineapig/*\//}:$line   $bp $cl${_lines[$line]}"
 513   elif (( $line < 10 )); then
 514     _msg "${_guineapig/*\//}:$line  $bp $cl${_lines[$line]}"
 515   elif (( $line > 0 )); then
 516     _msg "${_guineapig/*\//}:$line $bp $cl${_lines[$line]}"
 517   fi
 518 }
 519
 520 function _cleanup
 521 {
 522   rm -f $__debug $_potbelliedpig 2> /dev/null
 523 }
 524
 525 function _menu
 526 {
 527   _msg 'bashdb commands:
 528         break N         set breakpoint at line N
 529         break           list breakpoints & break condition
 530         condition foo   set break condition to foo
 531         condition       clear break condition
 532         delete N        clear breakpoint at line N
 533         delete          clear all breakpoints
 534         display EXP     evaluate and display EXP for each debug step
 535         display         show a list of display expressions
 536         undisplay N     remove display expression N
 537         list N M        display all lines of script between N and M
 538         list N          display 5 lines of script either side of line N
 539         list            display 5 lines if script either side of current line
 540         continue        continue execution upto next breakpoint
 541         next [N]        execute [N] statements (default 1)
 542         print expr      prints the value of an expression
 543         trace           toggle execution trace on/off
 544         ftrace [-u] func        make the debugger step into function FUNC
 545                         (-u turns off tracing FUNC)
 546         help            print this menu
 547         ! string        passes string to a shell
 548         quit            quit'
 549 }
 550
 551 shopt -u extglob
 552
 553 HISTFILE=~/.bashdb_history
 554 set -o history
 555 set +H
 556
 557 # strings to save and restore the setting of `extglob' in debugger functions
 558 # that need it
 559 _seteglob='local __eopt=-u ; shopt -q extglob && __eopt=-s ; shopt -s extglob'
 560 _resteglob='shopt $__eopt extglob'
 561
 562 _linebp=()
 563 let _trace=0
 564 let _i=1
 565
 566 # Be careful about quoted newlines
 567 _potbelliedpig=${TMPDIR-/tmp}/${_guineapig/*\//}.$$
 568 sed 's,\\$,\\\\,' $_guineapig > $_potbelliedpig
 569
 570 _msg "Reading source from file: $_guineapig"
 571 while read; do
 572   _lines[$_i]=$REPLY
 573   let _i=$_i+1
 574 done < $_potbelliedpig
 575
 576 trap _cleanup EXIT
 577 # Assuming a real script will have the "#! /bin/sh" at line 1,
 578 # don't stop at line 1 on the first run
 579 let _steps=1
 580 LINENO=-1
 581 trap '_steptrap $LINENO' DEBUG