This function requests a media-specific header for an open file. The specific header depends on the media type of the file and current track setting, in the case of multiple tracks. This header can be a raw header or a translated header.

This function does not change the current file position. It is highly recommended that mmioGetHeader be called before performing mmioRead because this information is normally required to understand the data that is read.

#define INCL_MMIOOS2
#include <os2.h>

HMMIO    hmmio;          /*  Open file handle. */
PVOID    pHeader;        /*  Pointer to header structure. */
LONG     lHeaderLength;  /*  Header structure size. */
PLONG    plBytesRead;    /*  # of bytes read. */
ULONG    ulReserved;     /*  Reserved. */
ULONG    ulFlags;        /*  Reserved. */
ULONG    rc;             /*  Return codes. */

rc = mmioGetHeader(hmmio, pHeader, lHeaderLength,
       plBytesRead, ulReserved, ulFlags);