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Perl 5 version 10.0 documentation
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prove -- A command-line tool for running tests against Test::Harness


prove [options] [files/directories]


  1. -b, --blib Adds blib/lib to the path for your tests, a la "use blib"
  2. -d, --debug Includes extra debugging information
  3. -D, --dry Dry run: Show the tests to run, but don't run them
  4. -h, --help Display this help
  5. -H, --man Longer manpage for prove
  6. -I Add libraries to @INC, as Perl's -I
  7. -l, --lib Add lib to the path for your tests
  8. --perl Sets the name of the Perl executable to use
  9. -r, --recurse Recursively descend into directories
  10. -s, --shuffle Run the tests in a random order
  11. --strap Define strap class to use
  12. -T Enable tainting checks
  13. -t Enable tainting warnings
  14. --timer Print elapsed time after each test file
  15. -v, --verbose Display standard output of test scripts while running them
  16. -V, --version Display version info

Single-character options may be stacked. Default options may be set by specifying the PROVE_SWITCHES environment variable.


prove is a command-line interface to the test-running functionality of Test::Harness . With no arguments, it will run all tests in the current directory.

Shell metacharacters may be used with command lines options and will be exanded via File::Glob::bsd_glob .


prove has a number of advantages over make test when doing development.

  • prove is designed as a development tool

    Perl users typically run the test harness through a makefile via make test . That's fine for module distributions, but it's suboptimal for a test/code/debug development cycle.

  • prove is granular

    prove lets your run against only the files you want to check. Running prove t/live/ t/master.t checks every *.t in t/live, plus t/master.t.

  • prove has an easy verbose mode

    prove has a -v option to see the raw output from the tests. To do this with make test , you must set HARNESS_VERBOSE=1 in the environment.

  • prove can run under taint mode

    prove's -T runs your tests under perl -T , and -t runs them under perl -t .

  • prove can shuffle tests

    You can use prove's --shuffle option to try to excite problems that don't show up when tests are run in the same order every time.

  • prove doesn't rely on a make tool

    Not everyone wants to write a makefile, or use ExtUtils::MakeMaker to do so. prove has no external dependencies.

  • Not everything is a module

    More and more users are using Perl's testing tools outside the context of a module distribution, and may not even use a makefile at all.


-b, --blib

Adds blib/lib to the path for your tests, a la "use blib".

-d, --debug

Include debug information about how prove is being run. This option doesn't show the output from the test scripts. That's handled by -v,--verbose.

-D, --dry

Dry run: Show the tests to run, but don't run them.


Add libraries to @INC, as Perl's -I.

-l, --lib

Add lib to @INC. Equivalent to -Ilib .


Sets the HARNESS_PERL environment variable, which controls what Perl executable will run the tests.

-r, --recurse

Descends into subdirectories of any directories specified, looking for tests.

-s, --shuffle

Sometimes tests are accidentally dependent on tests that have been run before. This switch will shuffle the tests to be run prior to running them, thus ensuring that hidden dependencies in the test order are likely to be revealed. The author hopes the run the algorithm on the preceding sentence to see if he can produce something slightly less awkward.


Sets the HARNESS_STRAP_CLASS variable to set which Test::Harness::Straps variable to use in running the tests.


Runs test programs under perl's -t taint warning mode.


Runs test programs under perl's -T taint mode.


Print elapsed time after each test file

-v, --verbose

Display standard output of test scripts while running them. Also sets TEST_VERBOSE in case your tests rely on them.

-V, --version

Display version info.


Please use the CPAN bug ticketing system at You can also mail bugs, fixes and enhancements to <> .


  • Shuffled tests must be recreatable


Andy Lester <andy at>


Copyright 2004-2006 by Andy Lester <andy at> .

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