[Swan-dev] atoi -- just say no

[D. Hugh Redelmeier]

Most uses of atoi are a mistake.  That's because it is not convenient to 
detect when a malformed number it present.  So good error handling isn't 
easy and (generally) coded that uses atoi just ignores problems.

So: any atoi call should be replaced.  With what?

strtoul is a useful function.  It gives you some capability to detect 
problems.

But we have our own ttoul function which is even better (see 
ipsec_ttoul(3)).

We should probably replace all strtoul calls too.

I did this work for plutomain.c and for some environment variable 
handling.  I hope to get to the rest of the codebase.

Through this process, I'm coming to think that a ttoul-like function that 
also does range-checking would be worthwhile.  It is just too easy to be 
lazy about range checks.