NAME
Devel::CheckLib - check that a library is available
DESCRIPTION
Devel::CheckLib is a perl module that checks whether a particular C library and its headers are available.
SYNOPSIS
# in a Makefile.PL or Build.PL
use lib qw(inc);
use Devel::CheckLib;
check_lib_or_exit( lib => 'jpeg', header => 'jpeglib.h' );
check_lib_or_exit( lib => [ 'iconv', 'jpeg' ] );
# or prompt for path to library and then do this:
check_lib_or_exit( lib => 'jpeg', libpath => $additional_path );
HOW IT WORKS
You pass named parameters to a function, describing to it how to build and link to the libraries.
It works by trying to compile this:
int main(void) { return 0; }
and linking it to the specified libraries. If something pops out the end which looks executable, then we know that it worked. That tiny program is built once for each library that you specify, and (without linking) once for each header file.
FUNCTIONS
All of these take the same named parameters and are exported by default. To avoid exporting them, use Devel::CheckLib ()
.
assert_lib
This takes several named parameters, all of which are optional, and dies with an error message if any of the libraries listed can not be found. Note: dying in a Makefile.PL or Build.PL may provoke a 'FAIL' report from CPAN Testers' automated smoke testers. Use check_lib_or_exit
instead.
The named parameters are:
- lib
-
Must be either a string with the name of a single library or a reference to an array of strings of library names. Depending on the compiler found, library names will be fed to the compiler either as
-l
arguments or as.lib
file names. (E.g.-ljpeg
orjpeg.lib
) - libpath
-
a string or an array of strings representing additional paths to search for libraries.
- LIBS
-
a
ExtUtils::MakeMaker
-style space-seperated list of libraries (each preceded by '-l') and directories (preceded by '-L').
And libraries are no use without header files, so ...
- header
-
Must be either a string with the name of a single header file or a reference to an array of strings of header file names.
- incpath
-
a string or an array of strings representing additional paths to search for headers.
- INC
-
a
ExtUtils::MakeMaker
-style space-seperated list of incpaths, each preceded by '-I'.
check_lib_or_exit
This behaves exactly the same as assert_lib()
except that instead of dieing, it warns (with exactly the same error message) and exits. This is intended for use in Makefile.PL / Build.PL when you might want to prompt the user for various paths and things before checking that what they've told you is sane.
If any library or header is missing, it exits with an exit value of 0 to avoid causing a CPAN Testers 'FAIL' report. CPAN Testers should ignore this result -- which is what you want if an external library dependency is not available.
PLATFORMS SUPPORTED
You must have a C compiler installed. We check for $Config{cc}
, both literally as it is in Config.pm and also in the $PATH.
It has been tested with varying degrees on rigourousness on:
- gcc (on Linux, *BSD, Mac OS X, Solaris, Cygwin)
- Sun's compiler tools on Solaris
- IBM's tools on AIX
- Microsoft's tools on Windows
- MinGW on Windows (with Strawberry Perl)
- Borland's tools on Windows
WARNINGS, BUGS and FEEDBACK
This is a very early release intended primarily for feedback from people who have discussed it. The interface may change and it has not been adequately tested.
Feedback is most welcome, including constructive criticism. Bug reports should be made using http://rt.cpan.org/ or by email.
When submitting a bug report, please include the output from running:
perl -V
perl -MDevel::CheckLib -e0
SEE ALSO
AUTHORS
David Cantrell <david@cantrell.org.uk>
David Golden <dagolden@cpan.org>
Thanks to the cpan-testers-discuss mailing list for prompting us to write it in the first place;
to Chris Williams for help with Borland support.
COPYRIGHT and LICENCE
Copyright 2007 David Cantrell. Portions copyright 2007 David Golden.
This module is free-as-in-speech software, and may be used, distributed, and modified under the same conditions as perl itself.
CONSPIRACY
This module is also free-as-in-mason software.