github.com/afumu/libc@v0.0.6/musl/src/locale/catgets.c (about)

     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  }