trim.c

/**
 * The MIT License (http://www.opensource.org/licenses/mit-license.php)
 * 
 * Copyright (c) 2010 Nexopia.com, Inc.
 * 
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 * 
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 **/
 
#define _GNU_SOURCE

#include <ctype.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "trim.h"

/**
 * trim(<string>, <string length>)
 *
 * Utility function that trims the whitespace from the end of a string in-place.  Returns the (new)
 * length of the trimmed string.
 **/
size_t trim(unsigned char *buf, size_t n)
{
	size_t i;

#ifdef __DEBUG__
	char *original_buf = strndup((char *)buf, n);
#endif
	for (i = strnlen((char *)buf, n) - 1; i >= 0; i--)
	{
		if (! isspace(buf[i]))
		{
			break;
		}
	}
	i++;
	buf[i] = '\0';
#ifdef __DEBUG__
	if (original_buf)
	{
		printf("trim.c debug: '%s'(%lu) => '%s'(%lu)\n", original_buf, strnlen(original_buf, n), buf, i);
		free(original_buf);
	}
	else
	{
		printf("trim.c debug: NULL/OOM => '%s'(%lu)\n", buf, i);
	}
#endif
	return i;
}