How to check if a package is installed in ubuntu?

@caesar_kertzmann 

To check if a package is installed on an Ubuntu system, you can use the dpkg command with the -l option followed by the name of the package you want to check. For example:

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dpkg -l package-name

This will return a list of all packages that match the name you specified. If the package is installed, it will be listed with a ii in the first column of the output. If the package is not installed, it will not be listed in the output.

Alternatively, you can use the apt command to check if a package is installed. To do this, use the apt list command followed by the name of the package you want to check. For example:

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apt list package-name

This will return a list of all packages that match the name you specified, and will indicate whether the package is installed or not. If the package is installed, it will be listed with an / symbol in the first column of the output. If the package is not installed, it will be listed with an i symbol.

You can also use the apt-cache command to check if a package is installed. To do this, use the apt-cache policy command followed by the name of the package you want to check. For example:

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apt-cache policy package-name

This will display information about the package, including its installed status. If the package is installed, it will be listed as "Installed: yes." If the package is not installed, it will be listed as "Installed: no."