From theAdd strtonum(3) manpage:
strtonum() is an OpenBSD extension. The existing alternativesmx(), such asa companion to strtonum(3) that preserves its safety
atoi(3C) and strtol(3C), are either impossible or difficult to useand error-reporting semantics while allowing the caller to specify a
safely.
It would be useful if there was a new function that had the use and safetyconversion base, similar to the strtol(3) family of functions.
properties of strtonum() but which understood base prefixes like the
strtol(3) family of functions does.