NeoStats/support.c

/* NeoStats - IRC Statistical Services 
** Copyright (c) 1999-2004 Adam Rutter, Justin Hammond, Mark Hetherington
** http://www.neostats.net/
**
**  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 2 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, write to the Free Software
**  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307
**  USA
**
** NeoStats CVS Identification
** $Id$
*/

/* @file potentially missing C library functions
 */

#include <stdio.h>
#include "stats.h"

#ifndef HAVE_STRNLEN
/* @brief find length of string up to count max
 *
 * @return length of string excluding NULL or count if longer
 *
 */
inline size_t strnlen(const char * src, size_t count)
{
	size_t len;

	/* Run through the string until we find NULL or reach count */
	for(len = 0; len < count; len++,src++) {
		if(*src == 0){
			return len;
		}
	}
#ifdef DEBUG
	printf("strnlen: len at max\n");
#endif

	/* src is longer or equal to count so return count */
	return count;
}
#endif /* HAVE_STRNLEN */

#ifndef HAVE_STRLCPY
/* @brief copy up to size-1 characters from src to dst and NULL terminate
 *
 * @return total characters written to string.
 *
 */
size_t
strlcpy(char *dst, const char *src, size_t size)
{
	size_t copycount;

    /* check size is safe */
	if (size <= 0) {
#ifdef DEBUG
		printf("strlcpy: size <= 0\n");
#endif
		return 0;
	}

	/* NULL pointer checks */
	if(!dst || !src) {
#ifdef DEBUG
		printf("strlcpy: dst (%p) or src (%p) is NULL\n", dst, src);
#endif
		return 0;
	}

	/* use strnlen so huge strings do not hold us up */
	for(copycount = 0; copycount < size-1 && *src!=0 ; copycount++) {
		*dst++=*src++;
	}

    /* Always null terminate */
	*dst = 0;

    /* count of characters written excluding NULL terminator */
	return copycount;
}
#endif /* HAVE_STRLCPY */

#ifndef HAVE_STRLCAT
/* @brief append at most size-len(dst)-1 chars from src to dst and NULL terminate
 *
 * @return total characters written to string.
 *
 */
size_t
strlcat(char *dst, const char *src, size_t size)
{
	size_t lendst;
	size_t copycount;

    /* check size is safe */
	if (size <= 0) {
#ifdef DEBUG
		printf("strlcat: size <= 0\n");
#endif
		return 0;
	}

	/* NULL pointer checks */
	if(!dst || !src) {
#ifdef DEBUG
		printf("strlcat: dst (%p) or src (%p) is NULL\n", dst, src);
#endif
		return 0;
	}

	/* if src contains NULL just NULL dst then quit to save a little CPU */
	if(*src == '\0') {
#ifdef DEBUG
		printf("strlcat: src is pointer to NULL\n");
#endif
		lendst = strnlen(dst, size);
		dst[lendst] = '\0';
		return 0;
	}

	/* use strnlen so huge strings do not hold us up */
	lendst = strnlen(dst, size);
	copycount = strnlen(src, size);

	/* bound copy size */
	if (lendst + copycount >= size) {
		copycount = size - lendst;
	}

	/* memcpy the desired amount */
	if (copycount > 0) {
		memcpy(dst + lendst, src, copycount);
		dst[lendst + copycount] = 0;
	}
	
    /* count of characters written excluding NULL terminator */
	return copycount;
}
#endif /* HAVE_STRLCAT */

#ifndef HAVE_STRNDUP
/* @brief allocate RAM and duplicate the passed string into the created buffer. 
 *  Always NULL terminates the new string.
 *  Suitable for partial string copies.
 *  Returned string will be count + 1 in length
 *
 * @return pointer to new string or NULL if failed to allocate
 *
 */
char *strndup(const char *src, size_t count)
{
	char *dup;
	
	/* validate inputs */
	if ((src == NULL) || (count < 0)) {
		return NULL;
	}
	
	/* Allocate count plus one for trailing NULL */
	dup = (char*)malloc(count+1);
	if (!dup) {
		return NULL;
	}
	
	/* Copy string into created buffer */
	memcpy(dup, src, count);
	dup[count] = 0;
	
	/* Return pointer to duplicated string */
	return dup;
}
#endif