As far as I can tell, $0 will give you something to work with and from there you can figure out the rest. Based on my limited testing: I think Perl is doing some fancy stuff to help you out there. After all, things often show up in the process table as having a "$0" of "perl foo" or "perl /path/to/foo", which correlates to the above two scenarios.

In the event $0 does not include the full path for you, you can always "guess" which one was called by going through your $ENV{PATH} and testing each one: 
my $my_path = $0;

foreach my $path (split(/:/, $ENV{PATH}))
{
     $my_path = "$path/$0" if (-f "$path/$0");
}

[download]
Either way, I think the functionality you are looking for is something like: 
my ($called_name) = $0 =~ m#/([^/]+)$#;

{
     no strict;

     &{"mode_$called_name"}() if (defined &{"mode_$called_name"});
}

sub mode_foo
{
     # If program is called as "foo"
}
sub mode_moo
{
     # If program is called as "moo"
}

[download]

In reply to Re: Finding out how you were called... by tadman
in thread Finding out how you were called... by suaveant

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