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DosSetFilePtrL

From EDM2

DosSetFilePtrL moves the read write pointer according to the type of move specified.

Syntax

DosSetFilePtrL (hFile, ib, method, ibActual)

Parameters

hFile (HFILE) input
The handle returned by a previous DosOpenL function.
ib (LONGLONG) input
The signed distance (offset) to move, in bytes.
method (ULONG) input
The method of moving.
Specifies a location in the file from where the ib to move the read/write pointer starts. The values and their meanings are described in the following list:
  • FILE_BEGIN - Move the pointer from the beginning of the file.
  • FILE_CURRENT - Move the pointer from the current location of the read write pointer.
  • FILE_END - Move the pointer from the end of the file. Use this method to determine a file s size.
ibActual (PLONGLONG) output
Address of the new pointer location.

Return Code

ulrc (APIRET) returns
DosSetFilePtrL returns one of the following values:
  • 0 NO_ERROR
  • 1 ERROR_INVALID_FUNCTION
  • 6 ERROR_INVALID_HANDLE
  • 132 ERROR_SEEK_ON_DEVICE
  • 131 ERROR_NEGATIVE_SEEK
  • 130 ERROR_DIRECT_ACCESS_HANDLE

Remarks

The read/write pointer in a file is a signed 64-bit number. A negative value for ib moves the pointer backward in the file; a positive value moves it forward. DosSetFilePtrL cannot be used to move to a negative position in the file.

DosSetFilePtrL cannot be used for a character device or pipe.

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