How stream buffer is implemented in C?

Question

I'm new to C, sorry if my question is dumb.

Where is the source code for IO stream? I want to see how the stream buffer is implemented, I can only see _IO_FILE struct in libc.h, but I don't see any internal buffer in this struct. Can anyone show me how can I locate the implmentation of stream buffer?

Answer 1

Where is the source code for IO stream?

For glibc the code is in libio directory.

In particular, _IO_new_file_fopen function implements fopen.