在字符串中差找某個字符串並按照相應格式改編並插入

 

int save2log(u1 *origin, int olen, u1 *buff)
{
    u1 head[6] = { 0x53, 0x41, 0x56, 0x45, 0x20 };
	u1 tail[3] = { 0x0D, 0x0A };
	u1  chartype;
	int offset = 0;
	int i = 0;
	int j = 0;
	int len = 0;
	int sflag = 0;
	int eflag = 0;

	for (i = 0; i < olen; i++)
	{
		chartype = ASCIICodeDetect(origin[i]);
		if (chartype == SMALL_LETTER)
		{
			origin[i] -= LETTER_DIST;
			chartype = BIG_LETTER;
		}
	}
	for (i = 0; i < olen; i++)
	{
		if (!memcmp(origin + i, head, 5) && (i+5 < olen))
		{
			sflag = i;
			while (1)
			{	
				if (origin[sflag] == 0x0D && origin[sflag + 1] == 0x0A)
				{	
					eflag = sflag + 1;
					break;
				}
				if (sflag > olen)
					break;
				sflag++;
			} 
	        len = eflag - i - 1 - 5;
			memcpy(buff + offset, "LOG ", 4); offset += 4;
			memcpy(buff + offset, origin+ i + 5, len); offset += len;
			memcpy(buff + offset, " SAVE", 5); offset += 5;
			memcpy(buff + offset, tail, 2); offset += 2;
			i = eflag;
		}
		else
		{	
			buff[offset] = origin[i]; offset += 1;
		}
	}

	return offset;
}

舉例：

如：log gpgga ontime 1

save gpggp ontime 1

unlogall

fix auto

四行指令都能識別

此代碼功能是把save gpgga ontime 1識別出來並修改成log gpgga ontime 1 save