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,$total)的实数整数值
从跟踪输出？
需要更改perl -d：Trace以获取数字,而不是：$top_number,$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 $total\n";
解决方法
我假设您希望通过循环查看每次迭代的$x和$total变量的值.来自0700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;