/*

 * Copyright (C) 1997, 1998, 1999, 2000 Free Software Foundation

 * Copyright (C) 1999, 2000 Red Hat, Inc.

 * All rights reserved.

 *

 * This file is part of the Gnome Library.

 *

 * This program is free software: you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation, either version 3 of the License, or

 * (at your option) any later version.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program.  If not, see <http://www.gnu.org/licenses/>.

 */

/*

  @NOTATION@

 */

/*

 *

 * Gnome utility routines.

 * (C)  1997, 1998, 1999 the Free Software Foundation.

 *

 * Author: Miguel de Icaza,

 */

#include <config.h>

#include "eggshell.h"

#include <stdlib.h>

#include <stdio.h>

#include <string.h>

#include <unistd.h>

#ifndef G_OS_WIN32

#include <pwd.h>

#endif

#include <glib.h>

/**

 * egg_shell:

 * @shell: the value of the SHELL env variable

 *

 * Retrieves the user's preferred shell.

 *

 * Returns: A newly allocated string that is the path to the shell.

 */

char *

egg_shell (const char *shell)

{

#ifndef G_OS_WIN32

	struct passwd *pw;

	int i;

	static const char shells [][14] = {

		/* Note that on some systems shells can also

		 * be installed in /usr/bin */

		"/bin/bash", "/usr/bin/bash",

		"/bin/zsh", "/usr/bin/zsh",

		"/bin/tcsh", "/usr/bin/tcsh",

		"/bin/ksh", "/usr/bin/ksh",

		"/bin/csh", "/bin/sh"

	};

	if (geteuid () == getuid () &&

	    getegid () == getgid ()) {

		/* only in non-setuid */

		if (shell != NULL) {

			if (access (shell, X_OK) == 0) {

				return g_strdup (shell);

			}

		}

	}

	pw = getpwuid(getuid());

	if (pw && pw->pw_shell) {

		if (access (pw->pw_shell, X_OK) == 0) {

			return g_strdup (pw->pw_shell);

		}

	}

	for (i = 0; i != G_N_ELEMENTS (shells); i++) {

		if (access (shells [i], X_OK) == 0) {

			return g_strdup (shells[i]);

		}

	}

	/* If /bin/sh doesn't exist, your system is truly broken.  */

	g_assert_not_reached ();

	/* Placate compiler.  */

	return NULL;

#else

	/* g_find_program_in_path() always looks also in the Windows

	 * and System32 directories, so it should always find either cmd.exe

	 * or command.com.

	 */

	char *retval = g_find_program_in_path ("cmd.exe");

	if (retval == NULL)

		retval = g_find_program_in_path ("command.com");

	g_assert (retval != NULL);

	return retval;

#endif

}