FAQ 3.6 How do I profile my Perl programs?

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3.6: How do I profile my Perl programs?

    (contributed by brian d foy, updated Fri Jul 25 12:22:26 PDT 2008)

    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


    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:


    CPAN has several other profilers that you can invoke in the same
    fashion. You might also be interested in using the "Benchmark" 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 describes the process in *The Perl
    Journal*, "Creating a Perl Debugger", http://www.ddj.com/184404522 , and
    "Profiling in Perl" http://www.ddj.com/184404580 .

    Perl.com has two interesting articles on profiling: "Profiling Perl", by
    Simon Cozens, http://www.perl.com/lpt/a/850 and "Debugging and Profiling
    mod_perl Applications", by Frank Wiles,
    http://www.perl.com/pub/a/2006/02/09/debug_mod_perl.html .

    Randal L. Schwartz writes about profiling in "Speeding up Your Perl
    Programs" for *Unix Review*,
    http://www.stonehenge.com/merlyn/UnixReview/col49.html , and "Profiling
    in Template Toolkit via Overriding" for *Linux Magazine*,
    http://www.stonehenge.com/merlyn/LinuxMag/col75.html .


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