hexchar
static const char hexchar[] = "0123456789ABCDEF";
(*quoted)[i++] = hexchar[(unquoted[0] >> 4) & 0xf];
(*quoted)[i++] = hexchar[(unquoted[0] ) & 0xf];
static const char hexchar[16] = "0123456789ABCDEF";
for (p = hexchar; *p; p++)
return p - hexchar;
p[i * 2] = hexchar[(*q >> 4) & 0xf];
p[i * 2 + 1] = hexchar[*q & 0xf];
(ch = hexchar(src + 1)) == -1) {