Open Err

FreeBASIC

Open Err
 
Opens both the standard input (stdin) and standard error (stderr) streams for file operations.

Syntax

Open Err [for mode] As [#]filenum As Long

Usage

Open Err [for mode] as [#]filenum
or
result = Open Err( [for mode[,]] as [#]filenum )

Parameters

mode
Ignored.
filenum
An unused file number.

Return Value

Zero is returned if Open Err completed successfully, otherwise a non-zero value is returned to indicate failure.

Description

This command opens stdin to read from and stderr to write to the console allowing read and write operations with normal file commands.

stderr is an output stream different from stdout allowing error messages to be redirected separately from the main console output.

The normal console commands, such as Color and Locate, do not work in this mode, because they do not accept a file number.

The [For Input|Output] mode is allowed for compatibility, but is ignored.

Runtime errors:
Open Err throws one of the following runtime errors:

(1) Illegal function call
    • Filenumber was not free at the time. use FreeFile to ensure that filenumber is free.

Example

Dim a As String
Open Err For Input  As #1
Print #1,"Please write something and press ENTER"
Line Input #1, a 
Print #1, "You wrote"; a
Close
Sleep


Differences from QB

  • New to FreeBASIC

See also