Open Cons
Opens the console's standard input (stdin) or output (stdout) streams for use in file operations.
Open Cons As [#]filenumber
Open Cons For Input As [#]filenumber
Open Cons For Output As [#]filenumber
result = Open Cons( [For {Input|Output},] As filenumber )
filenumber
In the first usage, Open Cons returns zero (0) on success and a non-zero error code otherwise.
Open Cons opens the console's stdin or stdout streams for reading or writing. A file number is bound to the stream, which is used in subsequent file operations, such as Input #. An available file number can be retrieved with FreeFile.
The Input file mode opens the stdin stream for reading file operations, such as Line Input #, while the Output file mode opens the stdout stream for writing file operations, such as Print #. The Output file mode is the default if not specified.
The stdin and stdout streams are the ones used when the calling process' input or output is redirected (piped) by OS commands, or when it is opened with Open Pipe.
To open both the stdin and stdout streams for file operations, a process must use multiple file numbers.
Runtime errors:
Open Cons throws one of the following runtime errors:
(1) Illegal function call
Syntax
Open Cons As [#]filenumber
Open Cons For Input As [#]filenumber
Open Cons For Output As [#]filenumber
Usage
result = Open Cons( [For {Input|Output},] As filenumber )
(or using the QB-like syntax,)
Open Cons [For {Input|Output}] As filenumberParameters
filenumber
Return Value
In the first usage, Open Cons returns zero (0) on success and a non-zero error code otherwise.
Description
Open Cons opens the console's stdin or stdout streams for reading or writing. A file number is bound to the stream, which is used in subsequent file operations, such as Input #. An available file number can be retrieved with FreeFile.
The Input file mode opens the stdin stream for reading file operations, such as Line Input #, while the Output file mode opens the stdout stream for writing file operations, such as Print #. The Output file mode is the default if not specified.
The stdin and stdout streams are the ones used when the calling process' input or output is redirected (piped) by OS commands, or when it is opened with Open Pipe.
To open both the stdin and stdout streams for file operations, a process must use multiple file numbers.
Runtime errors:
Open Cons 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 Cons For Input As #1
Open Cons For Output As #2
Print #2,"Please write something and press ENTER"
Line Input #1,a
Print #2, "You wrote : ";a
Close
Sleep
Open Cons For Input As #1
Open Cons For Output As #2
Print #2,"Please write something and press ENTER"
Line Input #1,a
Print #2, "You wrote : ";a
Close
Sleep
Differences from QB
- In QB the syntax was OPEN "CON:" FOR INPUT|OUTPUT AS [#] filenum
See also
