in src/oct.c [387:396]
static int char2int(char input)
{
if(input >= '0' && input <= '9')
return input - '0';
if(input >= 'A' && input <= 'F')
return input - 'A' + 10;
if(input >= 'a' && input <= 'f')
return input - 'a' + 10;
return 0;
}