Name
InputString Function
Class
Microsoft.VisualBasic.FileSystem
Syntax
InputString(filenumber, charcount
)
-
filenumber
(required; Integer) Any valid file number
-
charcount
(required; Integer) Number of characters to read from file
Return Value
A String containing charcount
characters
Description
Reads data from a file into a string variable
Rules at a Glance
InputString should only be used with files opened in input (
OpenMode.Input
) or binary mode (OpenMode.Binary
).InputString begins reading from the current position of the file pointer.
InputString returns all the characters it reads, regardless of their type. This include spaces, carriage returns, linefeeds, commas, end-of-file markers, unprintable characters, etc.
Once the function finishes reading
charcount
characters, it also advances the file pointercharcount
characters.
Example
If the file c:\data.txt contains the data:
abcdefghijklmnopq
the following code reads the characters, three at a time:
Dim fr As Integer = FreeFile( ) Dim sLine As String Dim i As Long FileOpen(fr, "c:\data2.txt", OpenMode.Input) For i = 1 To LOF(fr) \ 3 sLine = InputString(fr, 3) Console.WriteLine(sLine) Next FileClose(fr)
Programming Tips and Gotchas
InputString reads data written to a file using the Print, PrintLine, or FilePut functions.
InputString always attempts to precisely read
charcount
characters from the file. If there are nocharcount
characters from the position of the file pointer to the end of the file, InputString attempts to read beyond the ...
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