CODEWITHSUNDEEP
perldebugging
xyz
xyz

Reputation: 8917

How can I run through a Perl program step by step?

I have a Perl program written by someone else. When I run it, it silently exits without writing anything to the logfile. Is there a way I can run this Perl program step by step, line by line by the interpreter and thus get to see where it terminates?

Upvotes: 12

Views: 17223

Answers (4)

Jeremy Marshall
Jeremy Marshall

Reputation: 41

There is a Perl module called "ptkdb" which is a standalone Perl interactive debugger. It works using the Tcl/Tk GUI, so you'll need that, too.

Depending on your OS you'll need to add some required modules.

Invoke it using

perl -d:ptkdb <your script>

If running some Unix/Linux system, you also need an X server.

Upvotes: 4

dejjub-AIS
dejjub-AIS

Reputation: 1541

There are two ways. The first is the one which Hachi and llioin already gave which is using the command-line switch "-d".

Or use an IDE. I am tried and used Komodo IDE which works like charm.

Upvotes: 1

Ilion
Ilion

Reputation: 6872

Hachi has the answer. Use the Perl debugger by running perl with the -d flag. For information on how to use the debugger past starting it, see the Perl Debugging Tutorial.

Upvotes: 3

paxdiablo
paxdiablo

Reputation: 881123

Yes, there is the Perl debugger which you can invoke with perl -d.

Documentation can be found in perldoc perldebug and perldoc perldebtut.

Probably the most useful commands would be:

s                 - step into current line.
n                 - step over current line.
r                 - step out of current function.
p <expr>          - print the expression.
b <line|subnm>    - sets a breakpoint
T                 - produce a stack trace.
c [<line|subnm>]  - continue running with optional one-time breakpoint.
h                 - help (for other commands).

Upvotes: 31

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