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bashdpkg

How to use dpkg in silent mode

I try to test if some packages are installed in my script before run it. To do that by the dpkg command. This is my code :

dpkg -s dialog
dialogStatut=$?

if [ "$dialogStatut" -eq 1 ]; then
    //Install package
fi

I would like to make dpkg in silent mode (without echo). I have tried to put >&- 2>&- behind the command but if i do that the value is always 2 (if dialog is installed or not).

I have don't find solution in man dpkg. What is the best way to do that?

Solution

  • You are looking for 2> /dev/null

    if ! dpkg -s dialog 2> /dev/null; then
    ...
fi

    Consider just exiting your script to let dialog be installed explicitly rather than making your script responsible for doing so.