Determine whether a shared library is available to be loaded by Raku
use LibraryCheck;
if !library-exists('sndfile', v1) {
die "Cannot load libsndfile";
}This module provides a mechanism that will determine whether a named shared library is available and can be used by NativeCall.
It exports a single function library-exists that returns a boolean to
indicate whether the named shared library can be loaded and used. The
library name should be supplied without any (OS-dependent) "lib" prefix
and no extension (for example, 'crypt' for libcrypt.so).
This can be used in a builder to determine whether a module has a chance of working (and possibly aborting the build), or in tests to cause the tests that may rely on a missing library to be skipped.
The second positional argument is a Version object that
indicates the version of the library that is required, it defaults to
v1, if you don't care which version exists then it possible to pass a
new Version object without any version parts (i.e., Version.new()).
Many systems require that the version is specified, so if portability is
a concern, an actual version number should be given.
If the :exception adverb is passed to library-exists then an
exception (X::NoLibrary) will be thrown if the library isn't available
rather than returning False. So the case above can be more simply
written as:
library-check('sndfile', v1, :exception);The implementation is somewhat of a hack currently and definitely shouldn't be taken as an example of nice Raku code.
Assuming you have a working Rakudo installation you should be able to install this with zef:
# From the source directory
zef install .
# Remote installation
zef install LibraryCheck
Other install mechanisms may be become available in the future.
Suggestions/patches are welcomed via github at https://github.com/jonathanstowe/LibraryCheck/issues
I'd be particularly interested in having it work properly on all the platforms that rakudo will work on.
Please see the LICENCE file in the distribution.
© Jonathan Stowe 2015 - 2021