Name
EOF Function
Class
Microsoft.VisualBasic.FileSystem
Syntax
EOF(filenumber
)
-
filenumber
(required; Integer) Any valid file number
Return Value
A Boolean indicating when the end of the file has been reached
Description
Returns a Boolean indicating when the end of the file has been reached. Applies to files opened for binary, random, or sequential input.
Rules at a Glance
filenumber
must be an Integer that specifies a valid file number.If a file is opened for binary access, you cannot use EOF with the
Input
procedure. Instead, use LOF and Loc. If you want to use EOF, you must use FileGet rather thanInput
. In this case, EOF returnsFalse
until the previous FileGet procedure is unable to read an entire record.
Example
Dim fr As Integer = FreeFile( ) Dim sLine As String FileOpen(fr, "c:\data.txt", OpenMode.Input, OpenAccess.Read, _ OpenShare.Default, -1) Do While Not EOF(fr) sLine = LineInput(fr) Console.WriteLine(sLine) Loop
Programming Tips and Gotchas
EOF allows you to test whether the end of a file has been reached without generating an error.
Because you always write data to sequential files at the end of the file, the file marker is always at the end of the file, and EOF will therefore always return
True
when testing files opened with their modes set equal to eitherInput
orAppend
.
See Also
Get VB.NET Language in a Nutshell, Second Edition now with the O’Reilly learning platform.
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