DosSetFHState - Example Code

This example queries the file handle state of the file "DOSQFH.DAT".

 #define INCL_DOSFILEMGR   /* File Manager values */
 #define INCL_DOSERRORS    /* DOS error values    */
 #include <os2.h>
 #include <stdio.h>

 int main(VOID) {

 UCHAR       uchFileName[]   = "DOSQFH.DAT";    /* File to manipulate        */
 HFILE       fhQryFile       = 0;               /* File handle from DosOpen  */
 FILESTATUS3 fsts3FileInfo   = {{0}};  /* Information associated with file   */
 ULONG       ulOpenAction    = 0;                 /* Action taken by DosOpen */
 ULONG       FHState         = 0;                 /* File Handle State       */
 APIRET      rc              = NO_ERROR;          /* Return code             */

                 /* Create a file */

  rc = DosOpen(uchFileName, &fhQryFile,
               &ulOpenAction, 10L, FILE_NORMAL,
               OPEN_ACTION_CREATE_IF_NEW | OPEN_ACTION_OPEN_IF_EXISTS,
               OPEN_ACCESS_READWRITE | OPEN_SHARE_DENYNONE, 0L);
  if (rc != NO_ERROR) {
     printf("DosOpen error: return code = %u\n", rc);
     return 1;
  }

  rc = DosQueryFHState(fhQryFile, &FHState);
  if (rc != NO_ERROR) {
      printf("DosQueryFHState error: return code = %u\n", rc);
      return 1;
  } else printf("FHState is: %x\n", FHState);

    /*   Change state to indicate that data should not be cached */

    FHState &= 0x7F88;                  /* Turn off non-participating bits */
    rc = DosSetFHState(fhQryFile, FHState | OPEN_FLAGS_NO_CACHE);
    if (rc != NO_ERROR) {
        printf("DosSetFHState error: return code = %u\n", rc);
        return 1;
    }

    rc = DosClose(fhQryFile);
    /* Should check if (rc != NO_ERROR) here... */

    rc = DosDelete(uchFileName);      /* Delete the file */
    if (rc != NO_ERROR) {
        printf("DosDelete error: return code = %u\n", rc);
        return 1;
    } else {
        printf("File %s has been deleted.\n",uchFileName);
    }

   return NO_ERROR;
}