More advanced character device with read, write, open and release

chardev/test.c

@@ -0,0 +1,41 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <fcntl.h>
+
+int main(int argc, char **argv) {
+	int fd;
+
+	if (argc < 2) {
+		printf("I need the file to open as an argument!\n");
+		return 0;
+	}
+
+	fd = open(argv[1], O_RDONLY);
+
+	if (fd < 0) {
+		perror("open");
+		return fd;
+	}
+
+	close (fd);
+
+	fd = open(argv[1], O_RDWR | O_SYNC);
+
+	if (fd < 0) {
+		perror("open");
+		return fd;
+	}
+
+	close (fd);
+
+	fd = open(argv[1], O_WRONLY | O_NONBLOCK);
+
+	if (fd < 0) {
+		perror("open");
+		return fd;
+	}
+
+	close (fd);
+	return 0;
+}