How can I check if a Perl module is installed on my system from the command line?

Question

I tried to check if XML::Simple is installed in my system or not.

perl -e \'while (<@INC>) { while (<$_/*.pm>) { print \"$_\\n\"; } }\'
         


        

Answer 1

$ perl -MXML::Simple -le 'print $INC{"XML/Simple.pm"}'

From the perlvar entry on %INC:

• %INC

The hash %INC contains entries for each filename included via the do, require, or use operators. The key is the filename you specified (with module names converted to pathnames), and the value is the location of the file found. The require operator uses this hash to determine whether a particular file has already been included.

If the file was loaded via a hook (e.g. a subroutine reference, see require for a description of these hooks), this hook is by default inserted into %INC in place of a filename. Note, however, that the hook may have set the %INC entry by itself to provide some more specific info.