/* ----------------------------------------------------------------------- *

 *

 *  cat_path.c - boundary aware buffer management routines

 *

 *   Copyright 2002-2003 Ian Kent <raven@themaw.net> - All Rights Reserved

 *

 *   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, Inc., 675 Mass Ave, Cambridge MA 02139,

 *   USA; either version 2 of the License, or (at your option) any later

 *   version; incorporated herein by reference.

 *

 * ----------------------------------------------------------------------- */

#include <string.h>

#include <limits.h>

#include <ctype.h>

#include "automount.h"

/*

 * sum = "dir/base" with attention to buffer overflows, and multiple

 * slashes at the joint are avoided.

 */

int cat_path(char *buf, size_t len, const char *dir, const char *base)

{

	char *d = (char *) dir;

	char *b = (char *) base;

	char *s = buf;

	size_t left = len;

	if ((*s = *d))

		while ((*++s = *++d) && --left) ;

	if (!left) {

		*s = '\0';

		return 0;

	}

	/* Now we have at least 1 left in output buffer */

	while (*--s == '/' && (left++ < len))

		*s = '\0';

	*++s = '/';

	left--;

	if (*b == '/') 

		while (*++b == '/');

	while (--left && (*++s = *b++)) ;

	if (!left) {

		*s = '\0';

		return 0;

	}

	return 1;

}

size_t _strlen(const char *str, size_t max)

{

	const char *s = str;

	size_t len = 0;

	while (*s++ && len < max)

		len++;

	return len;

}

/* 

 * sum = "dir/base" with attention to buffer overflows, and multiple

 * slashes at the joint are avoided.  The length of base is specified

 * explicitly.

 */

int ncat_path(char *buf, size_t len,

	      const char *dir, const char *base, size_t blen)

{

	char name[PATH_MAX+1];

	size_t alen = _strlen(base, blen);

	if (blen > PATH_MAX || !alen)

		return 0;

	strncpy(name, base, alen);

	name[alen] = '\0';

	return cat_path(buf, len, dir, name);

}

/* Compare first n bytes of s1 and s2 and that n == strlen(s1) */

int _strncmp(const char *s1, const char *s2, size_t n)

{

	size_t len = strlen(s1);

	if (n && n != len)

		return n - len;

	return strncmp(s1, s2, n);

}