void *failtest_malloc(size_t size, const char *file, unsigned line);
void *failtest_realloc(void *ptr, size_t size,
const char *file, unsigned line);
+void failtest_free(void *ptr);
int failtest_open(const char *pathname,
const char *file, unsigned line, ...);
int failtest_pipe(int pipefd[2], const char *file, unsigned line);