OK, here's my quickie code. It won't catch fancy things like eval'd subs, etc., but it does what I need. 
#!/usr/bin/perl
use strict;

my %used_sub = ();
my %declard_sub = ();
my @imported_sub = ();
my @reserved = ();

my $keywords_define_file = '/System/Library/Perl/darwin/CORE/keywords.
+h';
if (open F, $keywords_define_file) {
    /^#define KEY_(\w+)/ and push @reserved, $1 while (<F>);
}
close F;

while (<>) {
    while (/(?:\A|[^\%\@\$\w>])(\w+)\s*\(/g) {
        $used_sub{$1}++;
    }
    while (/sub\s+(\w+)/g) {
        $declard_sub{$1}++;
    }
    if (/^use\s+\S+\s+qw\((.*)\)/) {
        push @imported_sub, $_ foreach split /\s+/, $1;
    }
        
}

delete @used_sub{@reserved};
delete @used_sub{@imported_sub};

print join("\n",
    'Declared subs (used):',
    sort( grep {exists $used_sub{$_}} keys %declard_sub ),
    '','',
    'Declared subs (unused):',
     sort( grep {!exists $used_sub{$_}} keys %declard_sub ),
    '','',
    'Used subs (declared):',
    sort( grep {exists $declard_sub{$_}} keys %used_sub ),
    '','',
    'Used subs (undeclared):',
    sort( grep {! exists $declard_sub{$_}} keys %used_sub ),
    ''
    );

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In reply to Re: How to check if a word is reserved by genecutl
in thread How to check if a word is reserved by genecutl

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