Question

我的目标是调试（逐步）下面的sample.pl脚本。

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

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

perl -d:Trace需要更改哪些才能获取数字，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。 POD没有指出Devel::Trace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;

Answer 2

看看Variable::Magic。它可以是变量“跟踪”的解决方案。

如何从Perl跟踪中查看变量的值？

2 个答案: