Question

Is there a smart way to detect whether a certain Perl module has been installed in your system?
My old sutpid way is to write a Perl script in which the only thing I do is just to use the module. If nothing croaks when I run the detect script, then I know the module has been installed, although I still don’t know which version and where the module has been installed .

thanks in advance.

Answer 1

Something like:

perl -MModule -e 'print "$Module::VERSION\n"' 2>/dev/null || echo "Not installed"

would give you the version of a given module, or tell you it isn’t installed. Usage would look like:

perl -MXML::Parser -e 'print "$XML::Parser::VERSION\n"' 2>/dev/null || echo "Not installed"

To find the module path, you could examine @INC to find possible locations, or you could perhaps look into perlwhich. There is also pmpath from pmtools.