同一个进程内open两次同一文件并读写

今天和同事讨论一个文件被open两次是否会成功， 以及交叉读写会有什么结果？

 

    FILE* fd1 = NULL; 
	FILE* fd2 = NULL; 

	char buffer1[40];
	char *buffer2 = "gggggggggg";
	int ret = 0, ret1;
    fd1 = fopen("./text", "rb+"); 

    if(NULL == fd1) 
    { 
        perror("open"); 

    } 
	fseek(fd1, 0, 0);
	ret = fread(buffer1, 1, sizeof(buffer1)-1, fd1);
	if (ret > 0)
		buffer1[ret] = '\0';
	printf("text1: %s \n",  buffer1);
	
    
    fd2 = fopen("./text", "rb+"); 

    if(NULL == fd2) 
    {
        perror("open"); 
    } 

	fseek(fd2, 0, 0);
	ret = fread(buffer1, 1, 10, fd2);
	if (ret > 0)
		buffer1[ret] = '\0';
	printf("text2: %s \n",  buffer1);
	

	fseek(fd1, 10, 0);
	ret = fwrite(buffer2, 1, strlen(buffer2), fd1);
	ret1 = fclose(fd1);
	printf("fclose(fd1) = %d \n",	ret1);

	fsee