cover - report coverage statistics
cover -report html_basic
Report coverage statistics in a variety of formats.
The summary option produces a short textual summary. Other reports are available
by using the report option.
The following reports are currently available:
html - detailed HTML reports (default)
html_basic - detailed HTML reports with syntax highlighting
text - detailed textual summary
compilation - output in a format similar to Perl errors
json - output in a JSON format
vim - show coverage information in vim gutter
The following command line options are supported:
-h -help - show help
-i -info - show documentation
-v -version - show version
-silent - don't print informational messages (default off)
-summary - give summary report (default on)
-report report_format - report format (default html)
-outputdir dir - directory for output (default given db)
-launch - launch report in viewer (if avail) (default off)
-select filename - only report on the file (default all)
-ignore filename - don't report on the file (default none)
-select_re RE - append to REs of files to select (default none)
-ignore_re RE - append to REs of files to ignore (default none)
-write [db] - write the merged database (default off)
-delete - drop database(s) (default off)
-dump_db - dump database(s) (for debugging) (default off)
-coverage criterion - report on criterion (default all available)
-test - drop database(s) and run make test (default off)
-gcov - run gcov to cover XS code (default on if using gcc)
-make make_prog - use the given 'make' program for 'make test'
-prefer_lib - prefer files in lib (default off)
other options specific to the report format
coverage_database [coverage_database ...]
The "-report", "-select", "-ignore",
"-select_re", "-ignore_re", and "-coverage"
options may be specified multiple times.
The following "-report" options are available in the core module.
Other reports may be available if they've been installed from external
- html|html_minimal (default)
- HTML reporting. Percentage thresholds are colour-coded and
configurable via -report_c0 <integer>, -report_c1 <integer>
and -report_c2 <integer>.:
0% 75% 90% 100%
| .. | .. | .. |
<c0 <c1 <c2 c3
red yellow orange green
- HTML reporting with syntax highlighting if PPI::HTML or
Perl::Tidy module is detected. Like html|html_minimal reporting,
percentage thresholds are colour-coded and configurable.
- Plain text reporting.
- A textual report in a format similar to that output by Perl
itself such that the report may be used by your editor or other reporting
tools to show where coverage is missing.
- A report in JSON format.
- A report suitable for use with the vim editor to show
coverage data in the sign column.
Any number of coverage databases may be specified on the command line. These
databases will be merged and the reports will be based on the merged
information. If no databases are specified the default database (cover_db)
will be used.
The "-write" option will write out the merged database. If no name is
given for the new database, the first database read in will be overwritten.
When this option is used no reports are generated by default.
Specify the "-select", "-select_re", "-ignore",
and "-ignore_re" options to report on specific files.
"-select" and "-ignore" are interpreted as shell globs;
"-select_re" and "-ignore_re" are interpreted as regular
Specify "-coverage" options to report on specific criteria. By default
all available information on all criteria in all files will be reported.
Available coverage options are statement, branch, condition, subroutine, pod,
and default (which equates to all available options). However, if you know you
only want coverage information for certain criteria it is better to only
collect data for those criteria in the first place by specifying them at that
point. This will make the data collection and reporting processes faster and
less memory intensive. See the documentation for Devel::Cover for more
If you want all *except* some criteria, then you can say something like
If you specify multiple "-report" options, make sure that they do not
conflict. For example, the different HTML reports will overwrite each other's
The "-test" option will delete the databases and run your tests to
generate new coverage data before reporting on it. Devel::Cover knows how to
work with standard Perl Makefiles as well as Module::Build based
distributions. For detailed instructions see the documentation for
ExtUtils::MakeMaker at <https://metacpan.org/module/ExtUtils::MakeMaker>
or for Module::Build at <https://metacpan.org/module/Module::Build> both
of which come as standard in recent Perl distributions.
The "-gcov" option will try to run gcov on any XS code. This requires
that you are using gcc of course. If you are using the "-test"
option will be turned on by default.
The "-prefer_lib" option tells Devel::Cover to report on files in the
lib directory even if they were used from the blib directory.
The following exit values are returned:
0 All operations were completed successfully.
>0 An error occurred.
With the -test option the exit status of the underlying test run is returned.
Did I mention that this is alpha code?
See the BUGS file.
Copyright 2001-2017, Paul Johnson (email@example.com)
This software is free. It is licensed under the same terms as Perl itself.
The latest version of this software should be available from my homepage: