FileSetPointer Function

Action

Sets the read/write position (in characters, not bytes) in an open file.

Syntax

iPos = FileSetPointer(hFile, iNewValue[,SetMode])

Variable	Description
`iPos`	New read/write position in the file. INTEGER.
`hFile`	The handle of the file to set the read/write position in. (You get a file handle by calling the FileOpen function.) HFILE.
`iNewValue`	Value that specifies new position, subject to value of `SetMode`. INTEGER.
`SetMode`	Optional: Mode to use to set new position. FILEPOS.

Notes

FileSetPointer sets the read/write position in an open file. It uses the value specified for iNewValue in different ways, depending on what was specified for SetMode, which is of type FILEPOS. The value of iNewValue must be such that the new position is between 0 and the end of the file (EOF). iNewValue can take any of the following values.

Value	How the Read/Write Position is Set
FP_START	(Default) The read/write position is set to `iNewValue`, which must be postive.
FP_END	The read/write position is set to the file length `iNewValue` characters before the end of the file. `iNewValue` must be a negative number. For example, `iCurrentPos = SYS_FileSetPointer(openFile, -4, FP_END)` sets the position to 4 characters before the end of the file. If you enter a positive number for FP_END, you will receive an error message.
FP_RELATIVE	The read/write position is set to the current position + `iNewValue`.

FileSetPointer returns the new read/write position. The new position cannot go past the end of file or be set before the beginning of the file. If the new position is beyond the borders of the file, Silk Test Classic raises an exception condition. The set position range is from the first character of the file to the last character of the file. No other position is valid.

The file header is not part of the file range. This means that the file’s first character can be up to 3 bytes into the raw file – and that is counted as the first position in the file.

This function is not designed for remote access.

Example

INTEGER iCurrentPos
HFILE openFile
openFile = SYS_FileOpen("c:\mytests\test.log", FM_READ)
// set pointer to 3
iCurrentPos = SYS_FileSetPointer(openFile, 3)
Print(iCurrentPos)
// set pointer 4 characters from end of file
iCurrentPos = SYS_FileSetPointer(openFile, -4, FP_END)
Print(iCurrentPos)
SYS_FileClose(openFile)

// Result: (file has 71 characters)
// 3
// 6
// 67