E.g., on an ubuntu system where it calls apt-get install pngnq pngcrush advancecomp optipng imagemagick and redirects stdout/stderr to /dev/null, in the background it just sits there waiting for the user to say Y. Various package managers are different but this should be apt-get install pngnq pngcrush advancecomp optipng imagemagick -y on ubuntu, etc.
E.g., on an ubuntu system where it calls
apt-get install pngnq pngcrush advancecomp optipng imagemagickand redirects stdout/stderr to /dev/null, in the background it just sits there waiting for the user to say Y. Various package managers are different but this should beapt-get install pngnq pngcrush advancecomp optipng imagemagick -yon ubuntu, etc.