What is difference between file descriptor and file pointer?

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What's the difference between a file descriptor and file pointer?

If I open file like this:

FILE *fp = fopen("mr32.txr","r");

then fp is file pointer or file descriptor? What is difference between them?

fp is a FILE pointer

File pointer:

1. It is high level interface
2. Passed to fread() and fwrite() functions
3. Includes buffering,error indication and EOF detection,etc.
4. Provides higher portability and efficiency.

File descriptor:

1. Low/Kernel level handler
2. passe to read() and write() of UNIX System Calls
3. Doesn't include buffering and such features
4. Less portable and lacks efficiency

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