+void test_reverse_from_file_then_from_stream_is_the_same(const char* test_filename) {
+ int pipefd[2];
+ if (pipe(pipefd) == -1) err(EX_OSERR, "Couldn't create pipe");
+
+ pid_t pid = fork();
+ if (pid == -1) err(EX_OSERR, "Couldn't fork");
+ if (pid == 0) {
+ if (close(pipefd[0]) == -1) err(EX_OSERR, "Couldn't close unneeded pipe descriptor");
+ FILE* to_second = fdopen(pipefd[1], "w");
+ if (to_second == NULL) err(EX_IOERR, "Couldn't open pipe for writing");
+ reverse_file(test_filename, to_second);
+ exit(0);
+ }
+ if (close(pipefd[1]) == -1) err(EX_OSERR, "Couldn't close unneeded pipe descriptor");
+ FILE* from_first = fdopen(pipefd[0], "r");
+ if (from_first == NULL) err(EX_IOERR, "Couldn't open pipe for reading");
+ char* out_temp_filename;
+ FILE* out_file;
+ make_temporary_file(&out_temp_filename, &out_file);
+ reverse_stream(from_first, out_file);
+ if (fclose(out_file) == EOF) err(EX_IOERR, "Couldn't close temporary file");
+
+ compare(test_filename, out_temp_filename);
+
+ if (unlink(out_temp_filename) == -1) err(EX_IOERR, "Couldn't remove temp output file");
+ free(out_temp_filename);
+}
+
+int main(int argc, char** argv) {
+ char* test_filename = "reverse.c";
+ if (argc > 2) {
+ errx(EX_USAGE, "usage: reverse_test [datafile]");
+ } else if (argc == 2) {
+ test_filename = argv[1];
+ }
+
+ test_reverse_twice_from_files_is_the_same(test_filename);
+ test_reverse_from_file_then_from_stream_is_the_same(test_filename);
+