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Diffstat (limited to 'examples/obashdb/bashdb.fns')
| -rw-r--r-- | examples/obashdb/bashdb.fns | 237 |
1 files changed, 237 insertions, 0 deletions
diff --git a/examples/obashdb/bashdb.fns b/examples/obashdb/bashdb.fns new file mode 100644 index 0000000..ac0612c --- /dev/null +++ b/examples/obashdb/bashdb.fns @@ -0,0 +1,237 @@ +# 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 "${_curline}" | grep -E "(${_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}" | grep -E "\\*(${_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" +} |