NAME

Devel::EndStats - Display run time and dependencies after running code

VERSION

This document describes version 0.20 of Devel::EndStats (from Perl distribution Devel-EndStats), released on 2015-03-26.

SYNOPSIS

 # from the command line
 % perl -MDevel::EndStats script.pl

 ##### sample output #####
 <normal script output, if any...>

 # BEGIN stats from Devel::EndStats
 # Program runtime duration: 0.055s
 # Total number of required files loaded: 132
 # Total number of required lines loaded: 48772
 # END stats

 ##### sample output (with verbose=1, some cut) #####
 <normal script output, if any...>

 # BEGIN stats from Devel::EndStats
 # Program runtime duration: 0.055s
 # Total number of required files loaded: 132
 # Total number of required lines loaded: 48772
 #   #  1   1747 lines  0.023489s( 43%)  Log/Any/App.pm (loaded by main)
 #   # 52   1106 lines  0.015112s( 28%)  Log/Log4perl/Logger.pm (loaded by Log::Log4perl)
 #   # 17    190 lines  0.011983s( 22%)  Log/Any/Adapter.pm (loaded by Log::Any::App)
 #   # 18    152 lines  0.011679s( 21%)  Log/Any/Manager.pm (loaded by Log::Any::Adapter)
 #   #  5    981 lines  0.007299s( 13%)  File/Path.pm (loaded by Log::Any::App)
 ...
 # END stats

DESCRIPTION

Devel::EndStats runs in the END block, displaying various statistics about your program, such as:

• how many seconds the program ran;

• how many required files and total number of lines loaded (from %INC);

• etc.

Some notes/caveats:

Devel::EndStats should be loaded before other modules, for example by running it on the command-line, as shown in the SYNOPSIS.

OPTIONS

Some options are accepted. They can be passed via the use statement:

 # from the command line
 % perl -MDevel::EndStats=verbose,1 script.pl

 # from script
 use Devel::EndStats verbose=>1;

or via the DEVELENDSTATS_OPTS environment variable:

 % DEVELENDSTATS_OPTS='verbose=1' perl -MDevel::EndStats script.pl

• verbose => BOOL (default: 0)

  Can also be set via VERBOSE environment variable. If set to true, display more statistics (like per-module statistics).

• sort => STR (default: '-time')

  Set how to sort the list of loaded modules ('file' = by file, 'time' = by load time, 'caller' = by first caller's package, 'order' = by order of loading, 'lines' = by number of lines). Only relevant when 'verbose' is on.

• force => BOOL (default: 0)

  By default, if BEGIN phase did not succeed, stats will not be shown. This option forces displaying the stats.

• hide_core => BOOL (default: 0)

  Whether to hide core modules while listing modules in verbose mode.

• hide_noncore => BOOL (default: 0)

  Whether to hide non-core modules while listing modules in verbose mode.

• show_memsize => BOOL (default: 0)

  Whether to show memory usage information. Currently this is done by probing /proc/$$/statm because some other memory querying modules are unusable (e.g. Devel::SizeMe currently segfaults on my system, Devel::InterpreterSize is too heavy).

FAQ

What is the purpose of this module?

This module might be useful during development. I first wrote this module when trying to reduce startup overhead of a command line application, by looking at how many modules the app has loaded and try to avoid loading modules whenever it's unnecessary.

Can you add (so and so) information to the stats?

Sure, if it's useful. As they say, (comments|patches) are welcome.

SEE ALSO

There are many modules on CPAN that can be used to generate dependency information for your code. Neil Bowers has written a review that covers most of them.

KNOWN ISSUES

* Timing and memory usage is inclusive instead of exclusive.

HOMEPAGE

Please visit the project's homepage at https://metacpan.org/release/Devel-EndStats.

SOURCE

Source repository is at https://github.com/perlancar/perl-Devel-EndStats.

BUGS

Please report any bugs or feature requests on the bugtracker website https://rt.cpan.org/Public/Dist/Display.html?Name=Devel-EndStats

When submitting a bug or request, please include a test-file or a patch to an existing test-file that illustrates the bug or desired feature.

AUTHOR

perlancar <perlancar@cpan.org>

COPYRIGHT AND LICENSE

This software is copyright (c) 2015 by perlancar@cpan.org.

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.

cpanm Devel::EndStats

perl -MCPAN -e shell
install Devel::EndStats