• safe_str.h
  • /* libFLAC - Free Lossless Audio Codec library
     * Copyright (C) 2013-2025  Xiph.Org Foundation
     *
     * Redistribution and use in source and binary forms, with or without
     * modification, are permitted provided that the following conditions
     * are met:
     *
     * - Redistributions of source code must retain the above copyright
     * notice, this list of conditions and the following disclaimer.
     *
     * - 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.
     *
     * - Neither the name of the Xiph.org Foundation 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 THE COPYRIGHT HOLDERS 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 THE FOUNDATION 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.
     */
    
    /* Safe string handling functions to replace things like strcpy, strncpy,
     * strcat, strncat etc.
     * All of these functions guarantee a correctly NUL terminated string but
     * the string may be truncated if the destination buffer was too short.
     */
    
    #ifndef FLAC__SHARE_SAFE_STR_H
    #define FLAC__SHARE_SAFE_STR_H
    
    static inline char *
    safe_strncat(char *dest, const char *src, size_t dest_size)
    {
    	char * ret;
    
    	if (dest_size < 1)
    		return dest;
    
    	/* Assume dist has space for a term character .. */
    	ret = strncat(dest, src, dest_size - strlen (dest));
    	/* .. but set it explicitly. */
    	dest [dest_size - 1] = 0;
    
    	return ret;
    }
    
    static inline char *
    safe_strncpy(char *dest, const char *src, size_t dest_size)
    {
    	char * ret;
    
    	if (dest_size < 1)
    		return dest;
    
    	ret = strncpy(dest, src, dest_size - 1);
    	dest [dest_size - 1] = 0;
    
    	return ret;
    }
    
    #endif /* FLAC__SHARE_SAFE_STR_H */