# bashdb.fns - Bourne-Again Shell Debugger functions _BUFSIZ=100 # Here after each statement in script being debugged. # Handle single-step and breakpoints. _steptrap() { let _curline=$1-1 # no. of line that just ran let "$_curline < 1" && let _curline=1 let "$_curline > $_firstline+$_BUFSIZ" && _readin $_curline let " $_trace" && _msg "$PS4, line $_curline: ${_lines[$(($_curline-$_firstline+1))]}" # if in step mode, decrement counter let " $_steps >= 0" && let _steps="$_steps - 1" # first check if line num or string brkpt. reached if _at_linenumbp || _at_stringbp; then _msg "Reached breakpoint at line $_curline" _cmdloop # enter debugger # if not, check whether break condition exists and is true elif [ -n "$_brcond" ] && eval $_brcond; then _msg "Break condition $_brcond true at line $_curline" _cmdloop # enter debugger # next, check if step mode and no. of steps is up elif let "$_steps == 0"; then _msg "Stopped at line $_curline" _cmdloop # enter debugger fi } # Debugger command loop. # Here at start of debugger session, when brkpt. reached, or after single-step. _cmdloop() { local cmd args # added support for default command (last one entered) while read -e -p "bashdb> [$lastcmd $lastargs] " cmd args; do if [ -z "$cmd" ]; then cmd=$lastcmd args=$lastargs fi lastcmd="$cmd" lastargs=$args # made commands to be debugger commands by default, no need for '*' prefix case $cmd in bp ) _setbp $args ;; #set brkpt at line num or string bc ) _setbc $args ;; # set break condition cb ) _clearbp ;; # clear all brkpts. g ) return ;; # start/resume execution s ) let _steps=${args:-1} return ;; # single-step N times(default 1) x ) _xtrace ;; # toggle execution trace pr ) _print $args ;; # print lines in file \? | h | help ) _menu ;; # print command menu hi ) history ;; # show command history q ) _cleanup; exit ;; # quit \! ) eval $args ;; # run shell command * ) _msg "Invalid command: $cmd" ; _menu ;; esac done } # see if next line no. is a brkpt. _at_linenumbp() { if [ -z "${_linebp}" ]; then return 1 fi echo "${_curline}" | egrep "(${_linebp%\|})" >/dev/null 2>&1 return $? } # search string brkpts to see if next line in script matches. _at_stringbp() { local l; if [ -z "$_stringbp" ]; then return 1; fi l=${_lines[$_curline-$_firstline+1]} echo "${l}" | egrep "*(${_stringbp%\|})*" >/dev/null 2>&1 return $? } # print message to stderr _msg() { echo -e "$@" >&2 } # set brkpt(s) at given line numbers and/or strings # by appending lines to brkpt file _setbp() { declare -i n case "$1" in "") _listbp ;; [0-9]*) #number, set brkpt at that line n=$1 _linebp="${_linebp}$n|" _msg "Breakpoint at line " $1 ;; *) #string, set brkpt at next line w/string _stringbp="${_stringbp}$@|" _msg "Breakpoint at next line containing $@." ;; esac } # list brkpts and break condition. _listbp() { _msg "Breakpoints at lines:" _msg "${_linebp//\|/ }" _msg "Breakpoints at strings:" _msg "${_stringbp//\|/ }" _msg "Break on condition:" _msg "$_brcond" } # set or clear break condition _setbc() { if [ -n "$@" ] ; then _brcond=$args _msg "Break when true: $_brcond" else _brcond= _msg "Break condition cleared" fi } # clear all brkpts _clearbp() { _linebp= _stringbp= _msg "All breakpoints cleared" } # toggle execution trace feature _xtrace() { let _trace="! $_trace" _msg "Execution trace \c" let " $_trace" && _msg "on." || _msg "off." } # print command menu _menu() { # made commands to be debugger commands by default, no need for '*' prefix _msg 'bashdb commands: bp N set breakpoint at line N bp string set breakpoint at next line containing "string" bp list breakpoints and break condition bc string set break condition to "string" bc clear break condition cb clear all breakpoints g start/resume execution s [N] execute N statements (default 1) x toggle execution trace on/off (default on) pr [start|.] [cnt] print "cnt" lines from line no. "start" ?, h, help print this menu hi show command history q quit ! cmd [args] execute command "cmd" with "args" default: last command (in "[ ]" at the prompt) Readline command line editing (emacs/vi mode) is available' } # erase temp files before exiting _cleanup() { rm $_dbgfile 2>/dev/null } # read $_BUFSIZ lines from $_guineapig into _lines array, starting from line $1 # save number of first line read in _firstline _readin() { declare -i _i=1 let _firstline=$1 SEDCMD="$_firstline,$(($_firstline+$_BUFSIZ))p" sed -n "$SEDCMD" $_guineapig > /tmp/_script.$$ while read -r _lines[$_i]; do _i=_i+1 done < /tmp/_script.$$ rm -f /tmp/_script.$$ 2>/dev/null } _print() { typeset _start _cnt if [ -z "$1" ] || [ "$1" = . ]; then _start=$_curline else _start=$1 fi _cnt=${2:-9} SEDCMD="$_start,$(($_start+$_cnt))p" pr -tn $_guineapig | sed -n "$SEDCMD" }