make-stderr-stream Function

Summary

Returns an output stream connected to stderr.

Package

system

Signature

make-stderr-stream => stream

Values

stream

An output stream.

Description

The function make-stderr-stream returns an output stream connected to stderr.

make-stderr-stream returns the same stream each time. Calling close on this stream has no effect (except that it forces the output).

Notes

1. On Microsoft Windows, if the stderr is not redirected on the command line then output to the stderr stream appears in a console.

   The console window will be created if it does not exist. That is not desirable for typical (non-console) applications. Therefore writing to the stderr stream is probably useful only in a console application (see the :console keyword argument in save-image), or when you know that stderr is going to be redirected.

2. Ensure your delivered Windows application calls make-stderr-stream at run time rather than in the build script, because it contains the handle of Windows stderr.
3. On macOS, applications that are launched from the desktop have their stderr redirected to the "console messages".