ref: f764b7c8342bd000d43eea624bc6265b8f3a8a7f
dir: /src/libc/string/strcat.c/
#include <string.h> #undef strcat char * strcat(char *restrict s1, const char *restrict s2) { char *ret = s1; while (*s1) ++s1; while ((*s1++ = *s2++) != 0) ; return ret; }