Cannot redirect stderr/stdout to file?

[joefiorini]

I'm having issues getting silentcast to work on my Arch installation running Awesome wm. I was going to open an issue with the output I'm getting, but redirecting stderr doesn't seem to output errors to a file. When I run: silentcast 2>&1 > silentcast.txt and then cat silentcast.txt I don't see the error output I saw when running the program. Worth noting that the error output is going to the terminal, so obviously the redirection isn't working.

[colinkeenan]

The reason redirect is not working is because Silentcast uses ffmpeg and from my testing just now, it is ffmpeg that is not allowing redirect. If you don't use 2>&1, you'll have something in silentcast.txt, but just not the error, which you are apparently getting from ffmpeg. I will investigate how to redirect ffmpeg error output to a file.

[colinkeenan]

From here, it looks like ffmpeg does sometimes allow redirect, but I think it doesn't when capturing the screen because it needs to let you know to press 'q' to stop it. From another answer on that link, you can use -report to generate a verbose report of what happens though. In order to use that, you would need to either edit genffcom, or the file it generates silentcast/ffcom. You can edit slientcast/ffcom while the "Get Ready .... Click OK when ready to start recording....." popup dialogue is displayed. I think that is the best way to do this. You can then grep the log for errors if you want. It will generate a file like silentcast/ffmpeg-20150123-083319.log.

[colinkeenan]

Instead of editing silentcast/ffcom, you could also do as I did and, from within the silentcast directory where ffcom was generated, cat ffcom, highlight and middle-click the ffmpeg command without the &... stuff at the end, and put -report at the end.