Function to flush internal buffer
The FFLUSH() function works in conjunction with the FOPEN() and FWRITE() functions to flush the internal buffer. The <expN> is the file handle returned by the FOPEN() function. The FFLUSH() function is used to bypass the I/O buffer and commit open text files to the current device. The FCLOSE() function also flushes associated buffers as it closes the specified file.
fwrite(fp,"Hello World") fflush(fp)