如何从Perl跟踪中查看变量的值？

Question

我的目标是调试(逐步)sample.pl下面的脚本.

问题:我没有得到变量的实际值($ top_number,$ x,$ total).

我的问题:如何从跟踪输出中查看($ top_number,$ x,$ total)的实数整数值？

perl -d:Trace为了得到数字需要改变什么,而不是:$ top_number,$ x,$ total？

跟踪输出示例:

[root@linux /tmp]# perl -d:Trace ./sample.pl 
>> ./sampl.pl:9: $top_number = 100;
>> ./sampl.pl:10: $x = 1;
>> ./sampl.pl:11: $total = 0;
>> ./sampl.pl:12: while ( $x <= $top_number ) {
>> ./sampl.pl:13:       $total = $total + $x;   # short form: $total += $x;
>> ./sampl.pl:14:       $x += 1;                # do you follow this short form?
>> ./sampl.pl:13:       $total = $total + $x;   # short form: $total += $x;
>> ./sampl.pl:14:       $x += 1;                # do you follow this short form?
>> ./sampl.pl:13:       $total = $total + $x;   # short form: $total += $x;
>> ./sampl.pl:14:       $x += 1;                # do you follow this short form?
.
.

[root@linux /tmp]#more sample.pl script

#!/usr/bin/perl 


$top_number = 100;
$x = 1;
$total = 0;
while ( $x <= $top_number ) {
    $total = $total + $x;   # short form: $total += $x;
    $x += 1;                # do you follow this short form?
}

print "The total from 1 to $top_number is $total\n";

Answer 1

我假设您希望通过循环查看每次迭代的$x和$total变量的值.Devel :: Trace的POD没有迹象表明它可以做到这一点.

但是,Devel :: DumpTrace可以.

perl -d:DumpTrace ./sample.pl

>>>>> hw.pl:7:      $top_number:100 = 100;
>>>>> hw.pl:8:      $x:1 = 1;
>>>>> hw.pl:9:      $total:0 = 0;
>>>>> hw.pl:10:     while ( $x:1 <= $top_number:100 ) {
>>>>> hw.pl:11:         $total:1 = $total:0 + $x:1;   # short form: $total:0 += $x:1;
>>>>> hw.pl:12:         $x:2 += 1;                # do you follow this short form?
>>>>> hw.pl:11:         $total:3 = $total:1 + $x:2;   # short form: $total:1 += $x:2;
>>>>> hw.pl:12:         $x:3 += 1;                # do you follow this short form?
>>>>> hw.pl:11:         $total:6 = $total:3 + $x:3;   # short form: $total:3 += $x:3;