strncat.c

#define SYSCLIB_DISABLE_BUILTINS
#include <sysclib.h>
 
char *strncat(char *restrict d, const char *restrict s, size_t n)
{
    char *a = d;
    d += strlen(d);
    while (n && *s) n--, *d++ = *s++;
    *d++ = 0;
    return a;
}