> what is the list of UB that nay professional C developer should be expected to know? Off the top of my head, as a non professional C programmer: - can’t rea

> what is the list of UB that nay professional C developer should be expected to know? Off the top of my head, as a non professional C programmer: - can’t read from uninitialized memory - one malloc = one free - signed overflow is undefined - pointers to stack variables can’t outlive the stack variable itself - can’t dereference NULL pointers (Obviously take this with a massive grain of salt, there are almost certainly important ones that I’m forgetting.) > null pointers are represented as 0, e.g. if(ptr). If(ptr) is guaranteed by the standard to work. Memset(ptr, 0, len) is not (and is very broken in other ways as well). > char and unsigned char are 8-bit bytes They’re guaranteed to be one byte, where a byte is at least 8 bits. So unless you’re trying to simulate %256 with an implicit conversion, or relying on unsigned overflow to turn 0xFF into 0x00, then you’ll be fine.