[SOLVED] Bash if condition to check if a ubuntu package has a newer version?

Issue

I need a bash line to check if a ubuntu package needs an upgrade or not.

For example, I want to check if the package 'firefox' needs an upgrade using dpkg or apt-get commands.

Hypthetical Example:

# Hypothetical example pseudo-code
if [[ $(firefox_needs_upgrade) ]]; then echo "Firefox needs upgrading";fi

Solution

Bash function:

apt_needs_upgrade() {

    NEEDS_UPGRADE=$(/usr/lib/update-notifier/apt-check -p 2>&1 >/dev/null | grep "^$1$" | wc -l)

    if [ "$NEEDS_UPGRADE" == 1 ]; then
        return 0; # 0 means true in bash!!!
    else
        return 1; # false
    fi;
}

Use it:

if apt_needs_upgrade "firefox"; then
    echo "Needs upgrading"
else
    echo "No need to upgrade"
fi;

Answered By - Basil Musa

Answer Checked By - Mary Flores (WPSolving Volunteer)