fx.diagnostics: add linux support for starting processes

fx.diagnostics/test/redirect.c

@@ -9,11 +9,21 @@ int main(int argc, const char **argv)
 	const char *exec = argv[1];
 	const char *msg = argv[2];
 
+	const char *args[] = {
+		"hello",
+		"world",
+	};
+
+	fx_process *self = fx_process_get_self();
+	const fx_hashtable *env = fx_process_get_environment(self);
+
 	fx_process_start_info info = {
-		.proc_args = NULL,
-		.proc_args_count = 0,
+		.proc_args = args,
+		.proc_args_count = sizeof args / sizeof args[0],
+		.proc_redirect_stdout = true,
 		.proc_redirect_stdin = true,
 		.proc_file_name = exec,
+		.proc_environment = env,
 	};
 
 	fx_process *process = fx_process_create(&info);
@@ -30,11 +40,20 @@ int main(int argc, const char **argv)
 		return -1;
 	}
 
-#if 1
+	printf("process stdin: %s\n", msg);
+
 	fx_stream *in = fx_process_get_stdin(process);
-	fx_stream_write_cstr(in, "Hello, world!\n", NULL);
+	fx_stream_write_cstr(in, msg, NULL);
+	fx_stream_write_char(in, '\n');
 	fx_process_close_stdin(process);
-#endif
+
+	fx_stream *out = fx_process_get_stdout(process);
+	printf("process stdout:\n");
+	printf("---------------------\n");
+
+	while (FX_OK(fx_stream_read_line_s(out, fx_stdout))) { }
+
+	printf("---------------------\n");
 
 	int result;
 	fx_process_wait(process, &result);