shadow/libmisc/list.c

/*
 * Copyright 1991 - 1994, Julianne Frances Haugh
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of Julianne F. Haugh nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY JULIE HAUGH AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL JULIE HAUGH OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

/* Removed duplicated code from gpmain.c, useradd.c, userdel.c and
   usermod.c.  --marekm */

#include <config.h>

#include "rcsid.h"
RCSID("$Id: list.c,v 1.3 1997/12/07 23:27:05 marekm Exp $")

#include "prototypes.h"
#include "defines.h"

/*
 * add_list - add a member to a list of group members
 *
 *	the array of member names is searched for the new member
 *	name, and if not present it is added to a freshly allocated
 *	list of users.
 */

char **
add_list(char **list, const char *member)
{
	int	i;
	char	**tmp;

	/*
	 * Scan the list for the new name.  Return the original list
	 * pointer if it is present.
	 */

	for (i = 0;list[i] != (char *) 0;i++)
		if (strcmp (list[i], member) == 0)
			return list;

	/*
	 * Allocate a new list pointer large enough to hold all the
	 * old entries, and the new entries as well.
	 */

	tmp = (char **) xmalloc ((i + 2) * sizeof member);

	/*
	 * Copy the original list to the new list, then append the
	 * new member and NULL terminate the result.  This new list
	 * is returned to the invoker.
	 */

	for (i = 0;list[i] != (char *) 0;i++)
		tmp[i] = list[i];

	tmp[i++] = xstrdup (member);
	tmp[i] = (char *) 0;

	return tmp;
}

/*
 * del_list - delete a member from a list of group members
 *
 *	the array of member names is searched for the old member
 *	name, and if present it is deleted from a freshly allocated
 *	list of users.
 */

char **
del_list(char **list, const char *member)
{
	int	i, j;
	char	**tmp;

	/*
	 * Scan the list for the old name.  Return the original list
	 * pointer if it is not present.
	 */

	for (i = j = 0;list[i] != (char *) 0;i++)
		if (strcmp (list[i], member))
			j++;

	if (j == i)
		return list;

	/*
	 * Allocate a new list pointer large enough to hold all the
	 * old entries.
	 */

	tmp = (char **) xmalloc ((j + 1) * sizeof member);

	/*
	 * Copy the original list except the deleted members to the
	 * new list, then NULL terminate the result.  This new list
	 * is returned to the invoker.
	 */

	for (i = j = 0;list[i] != (char *) 0;i++)
		if (strcmp (list[i], member))
			tmp[j++] = list[i];

	tmp[j] = (char *) 0;

	return tmp;
}

char **
dup_list(char * const *list)
{
	int i;
	char **tmp;

	for (i = 0; list[i]; i++)
		;

	tmp = (char **) xmalloc((i + 1) * sizeof(char *));

	i = 0;
	while (*list)
		tmp[i++] = xstrdup(*list++);

	tmp[i] = (char *) 0;
	return tmp;
}

int
is_on_list(char * const *list, const char *member)
{
	while (*list) {
		if (strcmp(*list, member) == 0)
			return 1;
		list++;
	}
	return 0;
}

/*
 * comma_to_list - convert comma-separated list to (char *) array
 */

char **
comma_to_list(const char *comma)
{
	char	*members;
	char	**array;
	int	i;
	char	*cp, *cp2;

	/*
	 * Make a copy since we are going to be modifying the list
	 */

	members = xstrdup (comma);

	/*
	 * Count the number of commas in the list
	 */

	for (cp = members, i = 0;;i++)
		if ((cp2 = strchr (cp, ',')))
			cp = cp2 + 1;
		else
			break;

	/*
	 * Add 2 - one for the ending NULL, the other for the last item
	 */

	i += 2;

	/*
	 * Allocate the array we're going to store the pointers into.
	 */

	array = (char **) xmalloc (sizeof (char *) * i);

	/*
	 * Empty list is special - 0 members, not 1 empty member.  --marekm
	 */

	if (!*members) {
		*array = (char *) 0;
		return array;
	}

	/*
	 * Now go walk that list all over again, this time building the
	 * array of pointers.
	 */

	for (cp = members, i = 0;;i++) {
		array[i] = cp;
		if ((cp2 = strchr (cp, ','))) {
			*cp2++ = '\0';
			cp = cp2;
		} else {
			array[i + 1] = (char *) 0;
			break;
		}
	}

	/*
	 * Return the new array of pointers
	 */

	return array;
}