Add a mechanism for redirecting stdout/stderr to the debug console

[ndarilek]

Hi folks,

I'm a blind screen reader user. Often I find myself needing to both debug programs traditionally, and scan through lots of log output on stdout/stderr. My typical approach for the latter is to redirect stdio to a log, open that log in a separate buffer, and search for what I'm interested in. Unfortunately, that has a few down sides:

• I now have two separate files open vs. just the one I'm immediately working on. Granted, there are ways to mitigate this, but none are particularly great.
• I have to search for what I'm interested in using text find commands. Those get the job done, but they aren't the best tool for the job.
• I think VS Code updates file content as it changes, but I'm not sure how often this happens.

Apparently there was once an "outputCapture": "std" launch.json parameter that redirected stdio to the debug console. I've been using the debug console for Flutter and other environments, and it has some nice advantages for reading logs as a screen reader user:

• Log output is right there in the debugging interface, not stashed away in another file, and in some workflow that's different than what I'd do for debugging.
• I imagine the console refresh rate is higher, if not instantaneous.
• I can use filter expressions to limit the output to whatever I'm interested in. If I want profiling data on a specific function, I can log the appropriate details, type the text in as a filter, and immediately arrow through the results I'm interested in. Compare that to opening log.txt, where I have to find the text I'm interested in, then use the slightly less ergonomic F3/Shift-F3, listen to VS Code prattle on about how many results it's found, pay close attention to whether I've hit the end of the file, etc.

Would it be possible to add a debug console redirection option to the existing stdio redirect options? Or does a method for this already exist? I scanned the manual but nothing jumped out at me.

Thanks!

[vadimcn]

"terminal": "console" in launch.json will redirect stdout and stderr to the debug console.

[ndarilek]

Interesting. I added that, but the tree of messages in the console only shows that the process was launched when I press F5. Am I missing something else?

[vadimcn]

Can you post your launch config?

[vadimcn]

Also, what OS?

[ndarilek]

Windows:

{
    // Use IntelliSense to learn about possible attributes.
    // Hover to view descriptions of existing attributes.
    // For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387
    "version": "0.2.0",
    "configurations": [
        {
            "type": "lldb",
            "request": "launch",
            "name": "Debug",
            "cargo": {
                "args": [
                    "build"
                ]
            },
            "args": [],
            "cwd": "${workspaceFolder}",
            "env": {
                "CARGO_MANIFEST_DIR": "${workspaceFolder}"
            },
            "terminal": "console"
        }
    ]
}

[vadimcn]

Windows

Alas, on Windows LLDB still lacks some features. In this case, it does not support capturing debuggee's stdout and stderr output, so it cannot be send to the debug console.