Parse a string with mem suffixes into a number
unsigned long long memparse(const char * ptr, char ** retptr);
ptr
Where parse begins
retptr
(output) Optional pointer to next char after parse completes
Parses a string into a number. The number stored at ptr is potentially suffixed with K (for kilobytes, or 1024 bytes), M (for megabytes, or 1048576 bytes), or G (for gigabytes, or 1073741824). If the number is suffixed with K, M, or G, then the return value is the number multiplied by one kilobyte, one megabyte, or one gigabyte, respectively.