In practice it's _worse_ than that because you probably don't want a "long", you probably want a particular size like a 64 bit integer. So you have to add ifdefs to call either strtol or strtoll depending on the size of "long" and "long long".

And if you are using base 16 then strtol will allow an optional "0x" prefix. So if you didn't want that you have to check for it manually.

Strtol also accepts leading whitespace so if you didn't want that you have to test manually for it.

Don't pass a zero base thinking it means base ten. This works almost all the time but misinterprets a leading zero to mean octal.

Good luck!