/*
   gcc -std=gnu99 -g -ggdb -Wall -pedantic -o test_kill_proc_with_pty test_kill_proc_with_pty.c -lutil

*/
#include <unistd.h>
#include <stdio.h>
#include <sys/select.h>
#include <string.h>
#include <stdlib.h>
#include <signal.h>
#include <sys/wait.h>
#include <errno.h>
#include <assert.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <ctype.h>
#include <pty.h>

/* the string the child writes */
char orig_string[] = "hello, world\n";

/* the string we expect to read back in the parent */
char result_string[] = "hello, world\r\n";

void
hexify (size_t bytes, const void *data)
{
	const char *p;
	size_t i;

	int add_space = 0;

	i = bytes;
	p = (const char *)data;
	while (i) {
		fprintf(stderr, "%02x", *p);
		i--;p++; add_space++;
		if ((add_space % 2) == 0) {
			fputc(' ', stderr);
		}
	}
	fputc('\n', stderr);

	add_space = 0;

	i = bytes;
	p = (const char *)data;

	while (i) {
		switch (*p)
		{
		case '\n':
			fprintf(stderr, "\\n");
			break;
		case '\r':
			fprintf(stderr, "\\r");
			break;
		default:
			fprintf(stderr, "%c", *p);
		}

		i--;p++; add_space++;
	}
	fputc('\n', stderr);
}

void
run_test (void)
{
	int    pty_master;
	pid_t  pid;

	pid = forkpty (&pty_master, NULL, NULL, NULL);

	if (pid < 0) {
		perror ("forkpty");
		exit (EXIT_FAILURE);
	} else if (pid) {
		int      status;
		char     buffer[1024];
		ssize_t  ret;
		int      nfds;
		fd_set   readfds;
		fd_set   exceptfds;

		FD_ZERO (&readfds);
		FD_ZERO (&exceptfds);

		FD_SET (pty_master, &readfds);

		/* Parent */
		nfds = pty_master+1;
		assert (select (nfds, &readfds, NULL, &exceptfds, NULL) == 1);
		assert (FD_ISSET (pty_master, &readfds));

		assert (! kill (-pid, SIGKILL));
		assert (waitpid (pid, &status, 0) == pid);

		memset (buffer, '\0', sizeof (buffer));
		ret = read (pty_master, buffer, sizeof (buffer));
		assert (ret > 0);

		if (strcmp (buffer, result_string)) {
			fprintf (stderr, "ERROR: incorrect output: result_string='%s', buffer='%s'\n",
					result_string, buffer);

			fprintf(stderr, "result_string:\n");
			hexify (strlen (result_string), result_string);

			fprintf(stderr, "buffer:\n");
			hexify (strlen (buffer), buffer);

			exit (EXIT_FAILURE);
		}

		close (pty_master);
	} else {
		/* Child */

#if 0
		(void)write (STDOUT_FILENO, orig_string, strlen (orig_string));
		/*fprintf(stdout, "%s", orig_string);*/
#else
		/* force a shell */
        /* This seems to make the problem easier to hit */
		system ("echo hello, world;sleep 999");
#endif
		exit (0);
	}
}

int
main(int argc, char *argv[])
{
	int i;
	int count = 100;

	if (argc == 2)
		count = atol (argv[1]);

	fprintf(stderr, "Running tests\n");

	for (i = 0; i < count; i++) {
		fprintf (stderr, "loop %d of %d\n", 1+i, count);
		run_test ();
	}

	fprintf(stderr, "Ran tests\n");
}