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60 non-PAUSE users.

Adam J. Kaplan ☺


Devel::NYTProf - line-by-line code profiler and report generator


 # profile code and write database to ./nytprof.out
 perl -d:NYTProf some_perl.pl

 # convert database into html

 # or into comma seperated files

 # or into any other format by implementing your own Devel::NYTProf::Reader
 # submit new implementations like nytprofhtml as bugs/patches for inclusion.
 # (reports go into ./profiler by default)


A bit of history and a shameless plug...

NYTProf stands for 'New York Times Profiler'. Indeed, this module was developed by The New York Times Co. to help our developers quickly identify bottlenecks in large Perl applications. The Times loves Perl and we hope the community will benefit from our work as much as we have from theirs.

Please visit http://open.nytimes.com, our open source blog to see what we are up to, http://code.nytimes.com to see some of our open projects and then check out htt://nytimes.com for the latest news!


Devel::NYTProf will profile your perl code line-by-line and enable you to create reports in HTML, CSV/plain text or any other format.

This module is implemented in XS (aka C) and the profiler is on par with the speed of Devel::FastProf. This is the first release, so it will get faster.

The real strenght of Devel::NYTProf isn't its speeds, but the included Devel::NYTProf::Reader module (and its implementations). See Devel::NYTProf::Reader for more information, but basically the Reader provides an interface to parsing NYTProf databases and outputing arbitrary reports. This means that unlike Devel::FastProf, you can easily implement your own output format without editing the C source and recompiling the module.

Included in the bin directory of this distribution are two scripts which implement the Devel::NYTProf::Reader interface:

  • nytprofcsv - creates comma delimited profile reports

  • nytprofhtml - creates a very cool HTML report (including statistics, source code and color highlighting)


WARNING: ignoring these settings may cause unintended side effects in code that might fork

The behavior of Devel::NYTProf may be modified substantially through the use of a few environment variables.


Enables fork detection and file locking and disables output buffering. This will have a severe effect on performance, so use only with code that can fork. You MUST use this with code that forks! [default: off]


Uses real wall clock time instead of CPU time. With this setting, the profiler will measure time in units of actual microseconds. The problem with this is that it includes time that your program was 'running' but not actually executing in the CPU (maybe it was waiting for its turn to run in the cpu, or maybe it was suspended). If you don't know anything about process scheduling, then don't worry about this setting. [default: off]


Tells the profiler to write output to STDOUT. [default: ./nytprof.out]


The Makefile.PL script will automatically try to determine some information about your system. This module is mostly XS (which is C, not Perl) and takes advantage of some less universal GNU C functions. It should work on any GNU C system, but has been verified to work on the following:

1. Solaris 8, (SunOS 5.8)
2. Solaris 9, (SunOS 5.9)
3. Ubuntu Linux 7.10 - Gutsy Gibbon
4. OpenBSD 4.1

With Perl 5.8.6, 5.8.7 and 5.8.8


No Windows support. I didn't test on Windows and it probably won't work.


nytprofhtml is a script included that produces html reports.

nytprofcsv is another script included that produces plain text CSV reports.

Devel::NYTProf::Reader is the module that powers the report scripts. You might want to check this out if you plan to implement a custom report. Its easy!


Adam Kaplan, akaplan at nytimes dotcom


Copyright (C) 2008 by Adam Kaplan and The New York Times Company

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself, either Perl version 5.8.8 or, at your option, any later version of Perl 5 you may have available.