I mostly use this for things I install from CPAN, which are (usually!) well-behaved. But your point is well taken. It also won't work if the module has any sort of error in it.

I found a copy of pmtools here in perl.org and I think you're referring to the pmpath program in it; to get the same effect as this, you would do vi `pmpath What::Ever`. But pmpath also has the same issue in that it does a require of the module.

So here's a variation that walks down your @INC statically until it finds a file fitting the description:

#!/usr/bin/perl -w
ARG:
foreach (@ARGV)
{
    next if /^-/;
    s|::|/|g;
    $_ .= '.pm' unless /\.pm$/;
    foreach my $d (@INC)
    {
        $_ = "$d/$_", next ARG if -f "$d/$_" and -r _;
    }
    die "Can't find a module named $_\n";
}
exec $ENV{EDITOR} || '/bin/vi', @ARGV;
[download]

Props to merlyn for pushing me to improve the code. ;-)