hex-ll.h

   1 #ifndef HEX_LL_H
   2 #define HEX_LL_H
   3
   4 extern const signed char hexval_table[256];
   5 static inline unsigned int hexval(unsigned char c)
   6 {
   7         return hexval_table[c];
   8 }
   9
  10 /*
  11  * Convert two consecutive hexadecimal digits into a char.  Return a
  12  * negative value on error.  Don't run over the end of short strings.
  13  */
  14 static inline int hex2chr(const char *s)
  15 {
  16         unsigned int val = hexval(s[0]);
  17         return (val & ~0xf) ? val : (val << 4) | hexval(s[1]);
  18 }
  19
  20 /*
  21  * Read `len` pairs of hexadecimal digits from `hex` and write the
  22  * values to `binary` as `len` bytes. Return 0 on success, or -1 if
  23  * the input does not consist of hex digits).
  24  */
  25 int hex_to_bytes(unsigned char *binary, const char *hex, size_t len);
  26
  27 #endif