toxdigit
#define toxdigit(c) ((isdigit(c))?todigit(c):(toupper(c)-(int)'A'+10))
#define toxdigit(c) ((isdigit(c))?todigit(c):(toupper(c)-(int)'A'+10))
#define toxdigit(c) ((isdigit(c))?todigit(c):(toupper(c)-(int)'A'+10))