DosChgFilePtr

This call moves the read/write pointer in accordance with the type of move specified.

DosChgFilePtr

(FileHandle, Distance, MoveType, NewPointer)

FileHandle (HFILE) - input

Handle returned by a previous DosOpen call.
Distance (LONG) - input
The offset to move, in bytes.
MoveType (USHORT) - input
Method of moving. Specifies a location in the file from where Distance to move the read/write pointer starts. Values and their meanings are:

Value

Definition
0
Beginning of the file.
1
Current location of the read/write pointer.
2
End of the file. Use this method to determine a file's size.
NewPointer (PULONG) - output
Address of the new pointer location.
rc (USHORT) - return
Return code descriptions are:
• NO_ERROR 1
  ERROR_INVALID_FUNCTION
  6
  ERROR_INVALID_HANDLE
  Remarks

  The read/write pointer in a file is a signed 32-bit number. A negative value moves the pointer backward in the file. A positive value moves the pointer forward. DosChgFilePtr cannot be used to seek to a negative position in the file.

  This call may not be used for a character device or pipe.

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