Today I wrote a script in which I had a sub declaration near the top: 
sub chk_timer;

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then at some point one or more lines like 
chktimer $_ for @timers;

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and at the end the actual sub definition: 
sub chktimer {
  # ...
}

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As you can see I mistyped the declaration, or changed my mind way through. Whatever, perl -c told me everything was OK. Incidentally, I always 
use strict;
use warnings;

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However I couldn't spot that typo and what I got was a runtime error: 
Can't access `chktimer' field in class Proc::ProcessTable::Process at 
+./scriptname.pl line 75

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instead. BTW: unfortunately in this case, the condition in which the actual line(s) in which the (alleged) function call is executed is very rare, so I had to wait quite a while until I could spot that error.

Now, of course perl has no way to understand that chk_timer was a typo for chktimer, but I wonder if it could be sensible to have a warning about subs that have been declared but not defined.

I can foresee objections to such a proposal in terms of deliberate symbol table manipulations, but even then I'm not really sure what the best choice could be... this is just a meditation after all!

In reply to Warning for "unused sub declarations"? by blazar

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