/* Test whether a basic vprintf invocation works. */ #include #include #include #include "../basic.h" static int indirect(char* format, ...) { va_list ap; va_start(ap, format); close(0); close(1); int fds[2]; if ( pipe(fds) < 0 ) err(1, "pipe"); if ( vprintf(format, ap) < 0 ) err(1, "vprintf"); if ( fflush(stdout) == EOF ) err(1, "fflush"); close(1); char buf[256]; size_t amount = fread(buf, 1, sizeof(buf) - 1, stdin); if ( ferror(stdin) ) err(1, "fread"); buf[amount] = '\0'; const char* expected = "hello world 42"; if ( strcmp(buf, expected) != 0 ) errx(1, "vprintf wrote '%s' instead of '%s'", buf, expected); va_end(ap); return 0; } int main(void) { return indirect("hello %s %d", "world", 42); }