Output to stdout

[qeezzo]

print to stdout if -o --output-filename is: -
cool feature to create own pipeline
swappy do the same thing

[gabm]

I believe there was an issue about that. I agree with your proposal!

current solution is: -o /dev/stdout.

[qeezzo]

Unfortunately, it is not possible :)

        if !output_filename.ends_with(".png") {
            log_result(
                "The only supported format is png, but the filename does not end in png",
                !APP_CONFIG.read().disable_notifications(),
            );
            return;
        }

[gabm]

then we should exclude - from that check. Would you provide a PR?