catgets.c raw

   1  #define _BSD_SOURCE
   2  #include <nl_types.h>
   3  #include <endian.h>
   4  #include <stdlib.h>
   5  #include <stdint.h>
   6  #include <errno.h>
   7  
   8  #define V(p) be32toh(*(uint32_t *)(p))
   9  
  10  static int cmp(const void *a, const void *b)
  11  {
  12  	uint32_t x = V(a), y = V(b);
  13  	return x<y ? -1 : x>y ? 1 : 0;
  14  }
  15  
  16  char *catgets (nl_catd catd, int set_id, int msg_id, const char *s)
  17  {
  18  	const char *map = (const char *)catd;
  19  	uint32_t nsets = V(map+4);
  20  	const char *sets = map+20;
  21  	const char *msgs = map+20+V(map+12);
  22  	const char *strings = map+20+V(map+16);
  23  	uint32_t set_id_be = htobe32(set_id);
  24  	uint32_t msg_id_be = htobe32(msg_id);
  25  	const char *set = bsearch(&set_id_be, sets, nsets, 12, cmp);
  26  	if (!set) {
  27  		errno = ENOMSG;
  28  		return (char *)s;
  29  	}
  30  	uint32_t nmsgs = V(set+4);
  31  	msgs += 12*V(set+8);
  32  	const char *msg = bsearch(&msg_id_be, msgs, nmsgs, 12, cmp);
  33  	if (!msg) {
  34  		errno = ENOMSG;
  35  		return (char *)s;
  36  	}
  37  	return (char *)(strings + V(msg+8));
  38  }
  39