mmioSeek function (mmiscapi.h)

The mmioSeek function changes the current file position in a file opened by using the mmioOpen function.


LONG mmioSeek(
  HMMIO hmmio,
  LONG  lOffset,
  int   iOrigin



File handle of the file to seek in.


Offset to change the file position.


Flags indicating how the offset specified by lOffset is interpreted. The following values are defined:

Name Description
Seeks to lOffset bytes from the current file position.
Seeks to lOffset bytes from the end of the file.
Seeks to lOffset bytes from the beginning of the file.

Return value

Returns the new file position, in bytes, relative to the beginning of the file. If there is an error, the return value is –1.


Seeking to an invalid location in the file, such as past the end of the file, might not cause mmioSeek to return an error, but it might cause subsequent I/O operations on the file to fail.

To locate the end of a file, call mmioSeek with lOffset set to zero and iOrigin set to SEEK_END.


Minimum supported client Windows 2000 Professional [desktop apps only]
Minimum supported server Windows 2000 Server [desktop apps only]
Target Platform Windows
Header mmiscapi.h (include Mmiscapi.h, Windows.h)
Library Winmm.lib
DLL Winmm.dll