I ran dolphin like this:
dolphin . &
I see messages in the console like these:
QPixmap::scaled: Pixmap is a null pixmap
How can I keep the console clean or silent?
You can redirect the output to a file or to nowhere.
Using output redirection > you can redirect stdout and/or stderr away from the terminal.
To redirect stdout and stderr to a file use &> log.txt.
If you just want output to go way use &> /dev/null.
So you new command would be dolphin . &> /dev/null &
&> redirects all output
use > or 1> to redirect stdout only
use 2> to redirect stderr only
Note: if you want to append to a file rather than overwrite it use >> in place of >.
