/*******************************************************************************

 * Copyright (c) 2004, 2006 QNX Software Systems and others.

 * All rights reserved. This program and the accompanying materials

 * are made available under the terms of the Eclipse Public License v1.0

 * which accompanies this distribution, and is available at

 * http://www.eclipse.org/legal/epl-v10.html

 *

 * Contributors:

 *     QNX Software Systems - initial API and implementation

 *     Wind River Systems, Inc.  

 *******************************************************************************/

#include "exec0.h"

#include <unistd.h>

#include <stdlib.h>

#include <stdio.h>

#include <errno.h>

#include <string.h>

#include <libgen.h>

#include <stdlib.h>

#include <termios.h>

/* from pfind.c */

extern char *pfind(const char *name);

pid_t

exec_pty(const char *path, char *const argv[], char *const envp[],

      const char *dirpath, int channels[3], const char *pts_name, int fdm)

{

	int pipe2[2];

	pid_t childpid;

	char *full_path;

	/*

	 * We use pfind() to check that the program exists and is an executable.

	 * If not pass the error up.  Also execve() wants a full path.

	 */ 

	full_path = pfind(path);

	if (full_path == NULL) {

		fprintf(stderr, "Unable to find full path for \"%s\"\n", (path) ? path : "");

		return -1;

	}

	/*

	 *  Make sure we can create our pipes before forking.

	 */ 

	if (channels != NULL) {

		if (pipe(pipe2) < 0) { 

			fprintf(stderr, "%s(%d): returning due to error: %s\n", __FUNCTION__, __LINE__, strerror(errno));

			free(full_path);

			return -1;

		}

	}

	childpid = fork();

	if (childpid < 0) {

		fprintf(stderr, "%s(%d): returning due to error: %s\n", __FUNCTION__, __LINE__, strerror(errno));

		free(full_path);

		return -1;

	} else if (childpid == 0) { /* child */

		chdir(dirpath);

		if (channels != NULL) {

			int fds;

			fds = ptys_open(fdm, pts_name);

			if (fds < 0) {

				fprintf(stderr, "%s(%d): returning due to error: %s\n", __FUNCTION__, __LINE__, strerror(errno));

				return -1;

			}

			/* Close the read end of pipe2 */

			if (close(pipe2[0]) == -1)

				perror("close(pipe2[0]))");

			/* close the master, no need in the child */

			close(fdm);

			set_noecho(fds);

			/* redirections */

			dup2(fds, STDIN_FILENO);   /* dup stdin */

			dup2(fds, STDOUT_FILENO);  /* dup stdout */

			dup2(pipe2[1], STDERR_FILENO);  /* dup stderr */

			close(fds);  /* done with fds. */

		}

		/* Close all the fd's in the child */

		{

			int fdlimit = sysconf(_SC_OPEN_MAX);

			int fd = 3;

			while (fd < fdlimit)

				close(fd++);

		}

		setpgid(getpid(), getpid());

		if (envp[0] == NULL) {

			execv(full_path, argv);

		} else {

			execve(full_path, argv, envp);

		}

		_exit(127);

	} else if (childpid != 0) { /* parent */

		set_noecho(fdm);

		if (channels != NULL) {

			/* close the write end of pipe1 */

			if (close(pipe2[1]) == -1)

				perror("close(pipe2[1])");

			channels[0] = fdm; /* Input Stream. */

			channels[1] = fdm; /* Output Stream.  */

			channels[2] = pipe2[0]; /* stderr Stream.  */

			//channels[2] = fdm; /* Input Stream.  */

		}

		free(full_path);

		return childpid;

	}

	free(full_path);

	return -1;                  /*NOT REACHED */

}

#ifdef __STAND_ALONE__

int main(int argc, char **argv, char **envp) {

	const char *path = "./bufferring_test";

	int channels[3] = { -1, -1, -1};

	int status;	

	FILE *app_stdin;

	FILE *app_stdout;

	FILE *app_stderr;

	char pts_name[32];

	int fdm;	

	char buffer[32];

	fdm = ptym_open(pts_name);

	status =  exec_pty(path, argv, envp, ".", channels, pts_name, fdm);

	if (status >= 0) {

		app_stdin = fdopen(channels[0], "w");	

		app_stdout = fdopen(channels[1], "r");	

		app_stderr = fdopen(channels[2], "r");	

		if (app_stdout == NULL || app_stderr == NULL || app_stdin == NULL) {

			fprintf(stderr, "PROBLEMS\n");

		} else {

			fputs("foo\n", app_stdin);

			fputs("bar\n", app_stdin);

			while(fgets(buffer, sizeof buffer, app_stdout) != NULL) {

				fprintf(stdout, "STDOUT: %s\n", buffer);

			}

			while(fgets(buffer, sizeof buffer, app_stderr) != NULL) {

				fprintf(stdout, "STDERR: %s\n", buffer);

			}

		}

	}

	fputs("bye\n", stdout);

	close(channels[0]);

	close(channels[1]);

	close(channels[2]);

	return 0;	

}

#endif