C函数fwrite（）不写入文件

I'm trying to write structures from tempGroupFile into GroupFile. fwrite() returns 1, when writing, but actually no data is written in the file GroupFile. Function printRec() prints out the structure on the screen. data is a variable of structure. File GroupFile is empty after these operations. Code:

我正在尝试将tempGroupFile中的结构写入GroupFile。写入时fwrite（）返回1，但实际上没有数据写入文件GroupFile。函数printRec（）打印出屏幕上的结构。数据是结构的变量。这些操作后，文件GroupFile为空。码：

GWTemp = fopen(tempGroupFile, "rb");
GW = fopen(GroupFile, "wb"); 
if((GW == NULL) || (GWTemp == NULL))
{
    puts("Failed to open file.");
    fflush(stdin);
    getchar();
    return 0;
}
while(fread(&data, sizeof data, 1, GWTemp))
{
    if(fwrite(&data, sizeof data, 1, GW))
    {
        printRec(data);
    }
}

1 个解决方案

#1

You need to close the file using fclose(GW) after the while loop. This makes sure all buffers are flushed so the file is written.

您需要在while循环后使用fclose（GW）关闭文件。这样可以确保刷新所有缓冲区以便写入文件。