This function updates information on a file I/O buffer of a file opened for buffered I/O.

#define INCL_MMIOOS2
#include <os2.h>

HMMIO        hmmio;      /*  Open file handle. */
PMMIOINFO    pmmioinfo;  /*  Buffer. */
USHORT       usFlags;    /*  Reserved. */
USHORT       rc;         /*  Return codes. */

rc = mmioSetInfo(hmmio, pmmioinfo, usFlags);