#include <sys/ioctl.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/select.h>
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <string.h>
#include <termios.h>
#include <unistd.h>

int write_to(const char * fname, int fd, const char * msg)
{
	const char * p = msg;
	int n_bytes = strlen(msg);
	while (n_bytes) {
		int r = write(fd, p, n_bytes);
		if (r < 0) {
			fprintf(stderr, "write %s failed: %d %s\n", fname, errno, strerror(errno));
			return 1;
		}
		if (r == 0) {
			// network sockets may return a 0-byte write; files never should
			fprintf(stderr, "write %s: unexpected network behavior\n", fname);
			return 1;
		}
		n_bytes -= r;
		p += r;
	}
	return 0;
}

const char uart_device[] = "/dev/ttyACM0";

int uart_connect(int fd)
{
	struct timeval t_start;
	gettimeofday(&t_start, 0 /*tz*/);
	int request_sent = 0, n_bytes;
	char buf[4096];

	while (1) {
		struct timespec t_out;
		struct timeval t_now;
		gettimeofday(&t_now, 0 /*tz*/);
		t_out.tv_nsec = (t_start.tv_usec - t_now.tv_usec + 1000000)*1000L;
		t_out.tv_sec = t_start.tv_sec - t_now.tv_sec;
		if (t_out.tv_nsec >= 1000000000L) {
			t_out.tv_nsec -= 1000000000L;
			t_out.tv_sec++;
		}

		fd_set rfds, wfds, efds;
		FD_ZERO(&rfds);
		FD_ZERO(&wfds);
		FD_ZERO(&efds);
		FD_SET(fd, &rfds);

		int r = pselect(fd + 1, &rfds, &wfds, &efds, &t_out, 0 /*sigmask*/);
		if (r == -1) {
			fprintf(stderr, "%s: pselect failed %d %s\n", uart_device, errno, strerror(errno));
			return 1;
		}
		if (r == 0) {
			if (request_sent) {
				// waited 1 s for response, time out
				fprintf(stderr, "timeout waiting for %s\n", uart_device);
				return 1;
			}

			// send request after waiting for 1 s
			request_sent = 1;

			if (write_to(uart_device, fd, "AT\n")) return 1;
			fprintf(stderr, "write AT\n");
			gettimeofday(&t_start, 0 /*tz*/);
		}

		if (FD_ISSET(fd, &rfds)) {
			if (ioctl(fd, FIONREAD, &n_bytes) < 0) {
				fprintf(stderr, "FIONREAD failed: %d %s\n", errno, strerror(errno));
				return 1;
			}
			if (n_bytes > (int) sizeof(buf)) n_bytes = (int) sizeof(buf);
			r = read(fd, buf, n_bytes);
			if (r < 0) {
				fprintf(stderr, "read %s failed: %d %s\n", uart_device, errno, strerror(errno));
				return 1;
			}
			buf[r] = 0;
			fprintf(stderr, "read %d bytes: \"%s\"\n", r, buf);
		}
	}

	return 0;
}

int main()
{
	int fd = open(uart_device, O_RDWR);
	if (fd == -1) {
		fprintf(stderr, "unable to connect: %d %s\n", errno, strerror(errno));
		return 1;
	}

	if (uart_connect(fd)) {
		close(fd);
		return 1;
	}

	close(fd);
	return 0;
}

#!/bin/bash
if [ -z "$1" ]; then
	ping 2$gt;&1 | sed -e "s/ping/`basename $0`/g"
	exit 1
fi

signalpingchild()
{
	for a in 1 2 3 4; do ps -f $gt;/dev/null; done
}

trap signalpingchild INT TERM HUP QUIT

ping -s18 -n $1 | while read a; do
	[ "${a#PING $1}" != "$a" -o -z "$a" ] && continue
	if [ "${a%statistics ---}" != "$a" ]; then
		echo ""
		echo "$a"
		cat
		break
	fi
	if [ "${a/icmp_seq/}" == "$a" ]; then
		echo -ne "\r\e[K"
		echo "$a"
		continue
	fi
	v="`echo \"$a\" | awk '{ d=$4; sub(":\$", "", d); \
		t=$7; sub("^time=", "", t); \
		x=log(t) + 3; if (x $gt; 5) x = x*16 - 16*5; \
		print "b=" $1 "; d=\\\"" d "\\\"; " $6 "; t=\\\"" t "\\\"; x=" x "; s=\\\"" $8 "\\\""; \
	}'`"
	eval "$v"
	if [ $b -ne $((18+8)) -o "$d" != "$1" -o "$s" != "ms" ]; then
		echo "$a: bad $v"
		continue
	fi
	# pretty-print
	echo -ne '\r\e[K' | awk "{
		t=$t;
		if (t<1000) { u=\"m\" }
		else if (t<1000000) { u=\"\"; t /= 1000 };
		for (x=0; x<$x; x++) b=b \"=\";
		printf \"%s%7.3f %ss %s\", \$0, t, u, b;
		exit}"
done &
wait $! # this convinces ping it is connected to a tty
	

#include <stdio.h>
#include <errno.h>
#include <fcntl.h>
#include <unistd.h>
#include <string.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/ioctl.h>
#define winsize __termios__winsize
#define termio __termios__termio
#include <linux/termios.h>

/*
* TIOCMSET and TIOCMGET are POSIX
* TIOCMODS and TIOCMODG are BSD (4.3 ?)
* MCSETA and MCGETA are HPUX
*/
int do_set(int fd, const char * bitstr, int bit, int on)
{
	if (bit == 0) {
		fprintf(stderr, "set(%s = %d): invalid bit\n", bitstr, on);
		return 1;
	}
	if (ioctl(fd, (on ? TIOCMBIS : TIOCMBIC), &bit)) {
		fprintf(stderr, "set(%s = %d) failed: %d %s\n", bitstr, on, errno, strerror(errno));
		return 1;
	}
	if (bit == TIOCM_CTS || bit == TIOCM_CAR || bit == TIOCM_RNG || bit == TIOCM_DSR)
		printf("set(%s = %d) warning: setting an input pin will be ignored\n", bitstr, on);
		else printf("set(%s = %d) success\n", bitstr, on);
	return 0;
}

int do_get(int fd, const char * bitstr, int bit, int quiet)
{
	int result;
	if (ioctl(fd, TIOCMGET, &result)) {
		fprintf(stderr, "get(%s) failed: %d %s\n", bitstr, errno, strerror(errno));
		return 1;
	}
	if (quiet) printf("%d", (result & bit) ? 1 : 0);
	else printf("%s = %d (%02x & %02x)\n", bitstr, (result & bit) ? 1 : 0, result, bit);
	return 0;
}

int getbit(const char * str)
{
	if (strcasecmp(str, "le") == 0) return TIOCM_LE;
	if (strcasecmp(str, "rts") == 0) return TIOCM_RTS;
	if (strcasecmp(str, "dtr") == 0) return TIOCM_DTR;
	if (strcasecmp(str, "st") == 0) return TIOCM_ST;
	if (strcasecmp(str, "sr") == 0) return TIOCM_SR;
	if (strcasecmp(str, "cts") == 0) return TIOCM_CTS;
	if (strcasecmp(str, "car") == 0) return TIOCM_CAR;
	if (strcasecmp(str, "cd") == 0) return TIOCM_CD;
	if (strcasecmp(str, "rng") == 0) return TIOCM_RNG;
	if (strcasecmp(str, "ri") == 0) return TIOCM_RI;
	if (strcasecmp(str, "dsr") == 0) return TIOCM_DSR;
	if (strcasecmp(str, "out1") == 0) return TIOCM_OUT1;
	if (strcasecmp(str, "out2") == 0) return TIOCM_OUT2;
	if (strcasecmp(str, "loop") == 0) return TIOCM_LOOP;
	return 0;
}

int main(int argc, char ** argv)
{
	if (argc != 3 && (argc != 4 || (argv[3][0] != '1' && argv[3][0] != '0' && strcmp(argv[3], "-q")))) {
		fprintf(stderr, "usage: %s dev pin [ 0 | 1 ]\n"
			"    pin 0 turns off pin, pin 1 turns on pin\n"
			"    pin without any argument reads its current state\n"
			"    add -q when reading to only output the bit\n"
			"        le: line enable (input, usually wired to dsr)\n"
			"        dtr: data terminal ready (output, dsr on other side)\n"
			"        rts: request to send (output, rts on other side)\n"
			"        st: secondary TXD (output)\n"
			"        sr: secondary RXD (output)\n"
			"        cts: clear to send (input, rts on other side)\n"
			"        car or cd: carrier detect (input)\n"
			"        rng or ri: ring indicator (input)\n"
			"        dsr: data set ready (input, dtr on other side)\n"
			"        out1: (output)\n"
			"        out2: (output)\n"
			"        loop: set loopback mode (for testing)\n", argv[0]);
		return 1;
	}
	int fd = open(argv[1], O_RDONLY);
	if (fd < 0) {
		fprintf(stderr, "failed to open \"%s\": %d %s\n", argv[1], errno, strerror(errno));
		return 1;
	}

	int r;
	if (argc == 4 && argv[3][0] != '-') r = do_set(fd, argv[2], getbit(argv[2]), argv[3][0] == '1' ? 1 : 0);
		else r = do_get(fd, argv[2], getbit(argv[2]), (argc == 4 && strcmp(argv[3], "-q") == 0));
	close(fd);
	return r;
}