调试Perl程序员的工作流程

Question

I am new to Perl and I have the following problem.
I have a log output and I have found where this log output comes from. I mean the subroutine in some module that prints it.

Now eg in Java via Eclipse I would use eg Call hierarchy and other utilities to see how/when/who calls the method and figure out how to reproduce what I need and debug.

How can I do this in Perl ? Via eg grep ? If I grep eg for the module name I get hundrends of lines ranging from use A require A C::B::A B::A C::B::A::some_routine C::B::A::some_other_routine etc.
On top of this I am worried that perhaps the routine I am interested in is not called directly but some script eg runs the module that is of interest to me via some obscure (to me due to my ignorance in Perl ) manner.

So how would I go debug something in Perl in the most efficient way? What do you Perl gurus suggest for me to do and become more efficient?

Answer 1

Run the program under the Perl debugger:

perl -d scriptname arguments...

Set a breakpoint in the function you care about, and when the program stops at the breakpoint use the T debugger command to display a stack trace, which will show where the function was called from.

From your comments, I'm not sure this actually addresses what you're looking for. Maybe what you want is a cross-reference of the Perl application? See the FAQ How do I cross-reference my Perl programs?

Answer 2

Most of the time getting a stack trace (along with some debugging info) is a good start. One can use standard Carp module to generate stack traces:

use Carp;  
print_to_log(Carp::longmess("We're here"));

Or there's an object-oriented module for that as well.

Answer 3

要在不修改任何代码的情况下获取调用堆栈的转储，可以使用perl命令行在Carp :: Always下运行程序：

perl -MCarp::Always my_program.pl