我希望能够(合理地)在Perl调试器中任意设置我的执行点.例如,在if的主体之前移动if并设置变量.
围绕perldebug(以及perldebguts和perl调试器POD)页面进行翻查表明,这种功能要么不受支持,要么没有记录.
解决方法
一个繁琐的解决方法是在整个代码中添加标签和条件goto语句.但是,根据您想要模拟此功能的严重程度,它可能是值得的.
POINT1: $GOTO=""; # $GOTO is our fake variable that we only set from the debugger
($a,$b,$c)=(1,2,3);
POINT2: $GOTO="";
if ($a < $b) {
goto $GOTO if $GOTO;
if ($a > $c) {
goto $GOTO if $GOTO;
print "foo\n";
} else {
goto $GOTO if $GOTO;
print "bar\n";
}
goto $GOTO if $GOTO;
} else {
goto $GOTO if $GOTO;
print "nothing\n";
goto $GOTO if $GOTO;
}
示例调试会话：
$perl -d debuggoto.pl
Loading DB routines from perl5db.pl version 1.28
Editor support available.
Enter h or `h h' for help,or `man perldebug' for more help.
main::(debuggoto.pl:1): POINT1: $GOTO=""; # $GOTO is our fake variable that we only set from the debugger
DB<1> n
main::(debuggoto.pl:2): ($a,3);
DB<1>
main::(debuggoto.pl:3): POINT2: $GOTO="";
DB<1>
main::(debuggoto.pl:4): if ($a < $b) {
DB<1>
main::(debuggoto.pl:5): goto $GOTO if $GOTO;
DB<1>
main::(debuggoto.pl:6): if ($a > $c) {
DB<1>
main::(debuggoto.pl:10): goto $GOTO if $GOTO;
DB<1>
main::(debuggoto.pl:11): print "bar\n";
DB<1>
bar
main::(debuggoto.pl:13): goto $GOTO if $GOTO;
DB<1> $GOTO="POINT2"
DB<2> n
main::(debuggoto.pl:3): POINT2: $GOTO="";
DB<2> $c=0
DB<3> n
main::(debuggoto.pl:4): if ($a < $b) {
DB<3>
main::(debuggoto.pl:5): goto $GOTO if $GOTO;
DB<3>
main::(debuggoto.pl:6): if ($a > $c) {
DB<3>
main::(debuggoto.pl:7): goto $GOTO if $GOTO;
DB<3>
main::(debuggoto.pl:8): print "foo\n";
DB<3>
foo
main::(debuggoto.pl:13): goto $GOTO if $GOTO;
DB<3>
Debugged program terminated. Use q to quit or R to restart,use o inhibit_exit to avoid stopping after program termination,h q,h R or h o to get additional info.
DB<3>
Use `q' to quit or `R' to restart. `h q' for details.
DB<3>
我想知道是否有可能构建一个使用这个想法的调试器.