How do I profile my Perl programs?

(This is the official perlfaq answer, minus any subsequent edits)

The Devel namespace has several modules which you can use to profile your Perl programs. The Devel::DProf module comes with Perl and you can invoke it with the -d switch:

$ perl -d:DProf program.pl

After running your program under DProf, you'll get a tmon.out file with the profile data. To look at the data, you can turn it into a human-readable report with the dprofpp program that comes with Devel::DProf:

$ dprofpp

You can also do the profiling and reporting in one step with the -p switch to dprofpp:

$ dprofpp -p program.pl

The Devel::NYTProf (New York Times Profiler) does both statement and subroutine profiling. It's available from CPAN and you also invoke it with the -d switch:

$ perl -d:NYTProf some_perl.pl

Like DProf, it creates a database of the profile information that you can turn into reports. The nytprofhtml command turns the data into an HTML report similar to the Devel::Cover report:

$ nytprofhtml

CPAN has several other profilers that you can invoke in the same fashion. You might also be interested in using the C to measure and compare code snippets.

You can read more about profiling in Programming Perl, chapter 20, or Mastering Perl, chapter 5.

perldebguts documents creating a custom debugger if you need to create a special sort of profiler. brian d foy descr