在C语言中怎样正常加载磁盘文件，请用一段简短的文字来进行描述
https://cplusplus.com/reference/cstdio/fopen/
fopen
FILE * fopen ( const char * filename, const char * mode );
Open file
Opens the file whose name is specified in the parameter filename and associates it with a stream that can be identified in future operations by the FILE pointer returned.
The operations that are allowed on the stream and how these are performed are defined by the mode parameter.
The returned stream is fully buffered by default if it is known to not refer to an interactive device (see setbuf).
The returned pointer can be disassociated from the file by calling fclose or freopen. All opened files are automatically closed on normal program termination.
The running environment supports at least FOPEN_MAX files open simultaneously.
打开文件
打开其名称在参数文件名中指定的文件，并将其与一个流相关联，该流可以在以后的操作中通过返回的 FILE 指针来标识。
流上允许的操作以及如何执行这些操作由 mode 参数定义。
如果已知返回的流不引用交互式设备（请参阅 setbuf），则默认情况下返回的流是完全缓冲的。
返回的指针可以通过调用 fclose 或 freopen 与文件解除关联。 所有打开的文件都会在程序正常终止时自动关闭。
运行环境至少支持同时打开 FOPEN_MAX 个文件。