a64l.c raw

   1  #include <stdlib.h>
   2  #include <string.h>
   3  #include <stdint.h>
   4  
   5  static const char digits[] =
   6  	"./0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
   7  
   8  long a64l(const char *s)
   9  {
  10  	int e;
  11  	uint32_t x = 0;
  12  	for (e=0; e<36 && *s; e+=6, s++) {
  13  		const char *d = strchr(digits, *s);
  14  		if (!d) break;
  15  		x |= (uint32_t)(d-digits)<<e;
  16  	}
  17  	return (int32_t)x;
  18  }
  19  
  20  char *l64a(long x0)
  21  {
  22  	static char s[7];
  23  	char *p;
  24  	uint32_t x = x0;
  25  	for (p=s; x; p++, x>>=6)
  26  		*p = digits[x&63];
  27  	*p = 0;
  28  	return s;
  29  }
  30