set_file_buffer Sets file buffering on the given file pointer intset_file_buffer intfp intbuffer Output using fwrite is normally buffered at 8K. This means that if there are two processes wanting to write to the same output stream (a file), each is paused after 8K of data to allow the other to write. set_file_buffer sets the buffering for write operations on the given filepointer fp to buffer bytes. If buffer is 0 then write operations are unbuffered. This ensures that all writes with fwrite are completed before other processes are allowed to write to that output stream. The function returns 0 on success, or EOF if the request cannot be honored. The following example demonstrates how to use set_file_buffer to create an unbuffered stream. See also fopen, fwrite.