From f57347c10e434da2b721d7ac77f9c5c542040d1f Mon Sep 17 00:00:00 2001
From: Michal Sojka <sojkam1@fel.cvut.cz>
Date: Tue, 22 Nov 2011 01:21:42 +0100
Subject: [PATCH] Add pty testing program

This program allows testing serial line disciplines on computers without
any serial port (like my laptop outside of docking station).
---
 misc/ptytest/Makefile  |  4 ++++
 misc/ptytest/ptytest.c | 52 ++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 56 insertions(+)
 create mode 100644 misc/ptytest/Makefile
 create mode 100644 misc/ptytest/ptytest.c

diff --git a/misc/ptytest/Makefile b/misc/ptytest/Makefile
new file mode 100644
index 0000000..d5b7062
--- /dev/null
+++ b/misc/ptytest/Makefile
@@ -0,0 +1,4 @@
+CFLAGS = -Wall -O2
+
+all: ptytest
+	./ptytest | hexdump -C
diff --git a/misc/ptytest/ptytest.c b/misc/ptytest/ptytest.c
new file mode 100644
index 0000000..2f46bf9
--- /dev/null
+++ b/misc/ptytest/ptytest.c
@@ -0,0 +1,52 @@
+#define _XOPEN_SOURCE 600
+#include <stdlib.h>
+#include <fcntl.h>
+#include <error.h>
+#include <errno.h>
+#include <stdio.h>
+#include <poll.h>
+#include <unistd.h>
+
+/*
+ * How I use this program:
+ * - on terminal 1: ./ptytest | hexdump -C
+ * - on root terminal: rmmod slcan; insmod ./slcan.ko; ( sleep 1; ip l set up dev slcan0) & slcan_attach -w /dev/pts/12
+ */
+
+int main()
+{
+	int master_fd;
+	master_fd = posix_openpt(O_RDWR | O_NOCTTY);
+	if (master_fd == -1)
+		error(1, errno, "posix_openpt");
+	if (grantpt(master_fd) == -1)
+		error(1, errno, "grantpt");
+	if (unlockpt(master_fd) == -1)
+		error(1, errno, "unlockpt");
+	fprintf(stderr, "%s\n", ptsname(master_fd));
+
+	struct pollfd fds[2] = {
+		{ .fd = 0, .events = POLLIN },
+		{ .fd = master_fd, .events = POLLIN },
+	};
+
+	while (1) {
+		int ret = poll(fds, 2, -1);
+		char buffer[100];
+		if (ret == -1)
+			error(1, errno, "poll");
+		if (fds[0].revents) {
+			ret = read(fds[0].fd, buffer, sizeof(buffer));
+			if (ret == -1) error(1, errno, "read(stdin)");
+			ret = write(fds[1].fd, buffer, ret);
+			if (ret == -1) error(1, errno, "write(tty)");
+		}
+		if (fds[1].revents) {
+			ret = read(fds[1].fd, buffer, sizeof(buffer));
+			if (ret == -1) error(1, errno, "read(tty)");
+			ret = write(1, buffer, ret);
+			if (ret == -1) error(1, errno, "write(stdout)");
+		}
+	}
+	return 0;
+}
-- 
2.39.2