ref: ebd513c2adeb9758701bf9f7a10b17ce58c2d1c8
dir: /lib/c/strcat.c/
#include <string.h>
#undef strcat
char *
strcat(char * restrict dst, const char * restrict src)
{
char *ret = dst;
while (*dst)
++dst;
while (*dst++ = *src++)
;
return ret;
}