toaruos/userspace/extra/serial-console.c

/* vim: tabstop=4 shiftwidth=4 noexpandtab
 * This file is part of ToaruOS and is released under the terms
 * of the NCSA / University of Illinois License - see LICENSE.md
 * Copyright (C) 2013-2014 Kevin Lange
 *
 * serial console
 *
 * Runs a dumb console on a serial port or something similar.
 *
 */
#include <stdio.h>
#include <stdint.h>
#include <stdlib.h>
#include <unistd.h>
#include <syscall.h>
#include <signal.h>
#include <termios.h>
#include <fcntl.h>
#include <sys/wait.h>

#include "lib/pthread.h"

int fd = 0;

int child_pid = 0;

int keep_echo = 0;
int dos_lines = 0;
int keep_canon = 0;

void *print_serial_stuff(void * garbage) {
	child_pid = gettid();

	while (1) {
		char buf[1024];
		size_t r = read(fd, buf, 1024);
		fwrite(buf, 1, r, stdout);
		fflush(stdout);
	}

	pthread_exit(garbage);
}

struct termios old;

void set_unbuffered() {
	tcgetattr(fileno(stdin), &old);
	struct termios new = old;
	if (!keep_canon) {
		new.c_lflag &= (~ICANON);
	}
	if (!keep_echo) {
		new.c_lflag &= (~ECHO);
	}
	tcsetattr(fileno(stdin), TCSAFLUSH, &new);
}

void set_buffered() {
	tcsetattr(fileno(stdin), TCSAFLUSH, &old);
}

int show_usage(int argc, char * argv[]) {
	printf(
			"Serial client.\n"
			"\n"
			"usage: %s [-e] [-r] [-c] [device path]\n"
			"\n"
			" -e     \033[3mkeep echo enabled\033[0m\n"
			" -c     \033[3mkeep canon enabled\033[0m\n"
			" -r     \033[3mtransform line feeds to \\r\\n\033[0m\n"
			" -?     \033[3mshow this help text\033[0m\n"
			"\n", argv[0]);
	return 1;
}

int main(int argc, char ** argv) {
	pthread_t receive_thread;
	pthread_t flush_thread;

	int arg = 1;
	char * device;

	while (arg < argc) {
		if (argv[arg][0] != '-') break;
		if (!strcmp(argv[arg], "-e")) {
			keep_echo = 1;
		} else if (!strcmp(argv[arg], "-r")) {
			dos_lines = 1;
		} else if (!strcmp(argv[arg], "-c")) {
			keep_canon = 1;
		} else if (!strcmp(argv[arg], "-?")) {
			return show_usage(argc, argv);
		} else {
			fprintf(stderr, "%s: Unrecognized option: %s\n", argv[0], argv[arg]);
		}
		arg++;
	}

	if (arg == argc) {
		device = "/dev/ttyS0";
	} else {
		device = argv[arg];
	}

	set_unbuffered();

	fd = open(device, 0, 0);

	pthread_create(&receive_thread, NULL, print_serial_stuff, NULL);

	while (1) {
		char c = fgetc(stdin);
		if (c == 0x1D) { /* ^] */
			while (1) {
				printf("serial-console> ");
				set_buffered();
				fflush(stdout);

				char line[1024];
				fgets(line, 1024, stdin);

				if (feof(stdin)) {
					kill(child_pid, SIGKILL);
					printf("Waiting for threads to shut down...\n");
					while (wait(NULL) != -1);
					printf("Exiting.\n");
					return 0;
				}

				int i = strlen(line);
				line[i-1] = '\0';

				if (!strcmp(line, "quit")) {
					kill(child_pid, SIGKILL);
					printf("Waiting for threads to shut down...\n");
					while (wait(NULL) != -1);
					printf("Exiting.\n");
					return 0;
				} else if (!strcmp(line, "continue")) {
					set_unbuffered();
					fflush(stdout);
					break;
				}
			}
		} else {
			if (dos_lines && c == '\n') {
				char buf[1] = {'\r'};
				write(fd, buf, 1);
			}
			char buf[1] = {c};
			write(fd, buf, 1);
		}
	}

	close(fd);
	set_buffered();
	return 0;
}