Re: strtonum(3) from OpenBSD?

[Marc Balmer <marc%msys.ch@localhost>]

> > OpenBSD has the strtonum(3) function to reliably convert string  
> > values
> > to an
> > integer since the 3.6 release.
>
> I don't personally remember the previous thread about it, but the
> various immediate problems I see with it:
>
> Instead of returning an error code it returns a string, assuming the
> only consumers are humans; also this error string is non-localizable.
> Also, although it claims to be safer this is only a utility wrapper
> around strtoll(3).

I find a check like

strtonum(str, 0, 128, &errstr);
if (errstr) {
  ...
}

more readable than the somewhat clumsy

          errno = 0;
           lval = strtol(buf, &ep, 10);
           if (buf[0] == '\0' || *ep != '\0')
                   goto not_a_number;
           if (errno == ERANGE && (lval == LONG_MAX || lval ==  
LONG_MIN))
                   goto out_of_range;

construct that is needed with strtol.

> That said, if it is needed for portability because many programs  
> expect
> it in libc, it might be useful...

Yes, already more than one program apparently use it.  And at least one
more once we have it ;)