safestring.cpp

著名的 helix realplayer 基于手机 symbian 系统的 播放器全套源代码

/* ***** BEGIN LICENSE BLOCK ***** 
 * Version: RCSL 1.0/RPSL 1.0 
 *  
 * Portions Copyright (c) 1995-2002 RealNetworks, Inc. All Rights Reserved. 
 *      
 * The contents of this file, and the files included with this file, are 
 * subject to the current version of the RealNetworks Public Source License 
 * Version 1.0 (the "RPSL") available at 
 * http://www.helixcommunity.org/content/rpsl unless you have licensed 
 * the file under the RealNetworks Community Source License Version 1.0 
 * (the "RCSL") available at http://www.helixcommunity.org/content/rcsl, 
 * in which case the RCSL will apply. You may also obtain the license terms 
 * directly from RealNetworks.  You may not use this file except in 
 * compliance with the RPSL or, if you have a valid RCSL with RealNetworks 
 * applicable to this file, the RCSL.  Please see the applicable RPSL or 
 * RCSL for the rights, obligations and limitations governing use of the 
 * contents of the file.  
 *  
 * This file is part of the Helix DNA Technology. RealNetworks is the 
 * developer of the Original Code and owns the copyrights in the portions 
 * it created. 
 *  
 * This file, and the files included with this file, is distributed and made 
 * available on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER 
 * EXPRESS OR IMPLIED, AND REALNETWORKS HEREBY DISCLAIMS ALL SUCH WARRANTIES, 
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 * FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. 
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 * ***** END LICENSE BLOCK ***** */ 

#include "hxtypes.h" /* for UINT32 */

#include "safestring.h"

#include "hlxclib/stdio.h" // vsnprintf()

char* SafeStrCpy(char* pDestStr, const char* pSourceStr, UINT32 ulBufferSize)
{
    // Validate parameters and if invalid just return pDestStr like strncpy does.
    if (pDestStr && pSourceStr && ulBufferSize)
    {
        // strncpy does not NULL terminate if ulBufferSize is less than or equal to the source string length.  Always make
        // sure the string is NULL terminated.
        strncpy(pDestStr, pSourceStr, ulBufferSize); /* Flawfinder: ignore */
        pDestStr[ulBufferSize-1] = '\0';
    }

    return pDestStr;
}

char* SafeStrCat(char* pDestStr, const char* pSourceStr, UINT32 ulBufferSize)
{
    // Validate parameters and if invalid just return pDestStr like strcat does.
    if (pDestStr && pSourceStr && ulBufferSize)
    {
        // Find the end of the destination string just like strcat does
        char* pDestStrEnd = pDestStr;
        while (*pDestStrEnd)
        {
	    pDestStrEnd++;
        }

        UINT32 ulDestStrLength = pDestStrEnd - pDestStr;

        // If the length of the destination string is longer than the buffer size then we cannot concatenate anything
        if (ulDestStrLength < ulBufferSize)
        {
	    // We have room to concatenate so figure out how much of the buffer contained in the destination string we
	    // can use and copy the source string in.
	    SafeStrCpy(pDestStrEnd, pSourceStr, ulBufferSize - ulDestStrLength);
        }
    }

    return pDestStr;
}

int SafeSprintf(char* pBuffer, UINT32 ulBufferSize, const char* pFormatStr, ...)
{
    int nCharsWritten = 0;

    // Validate parameters and if invalid just return 0.
    if (pBuffer && ulBufferSize && pFormatStr)
    {
        va_list argptr;
        va_start(argptr, pFormatStr);

        nCharsWritten = vsnprintf(pBuffer, ulBufferSize, pFormatStr, argptr);
        pBuffer[ulBufferSize-1] = '\0';

        va_end(argptr);
    }

    return nCharsWritten;
}