Check if a package is installed and then install i

问题:

I'm working on a Ubuntu system and currently this is what I'm doing:

if ! which command > /dev/null; then
   echo -e "Command not found! Install? (y/n) \c"
   read
   if "$REPLY" = "y"; then
      sudo apt-get install command
   fi
fi

Is this what most people would do? Or is there a more elegant solution?

回答1:

To check if packagename was installed, type:

dpkg -s <packagename>

You can also use dpkg-query that has a neater output for your purpose, and accepts wild cards, too.

dpkg-query -l <packagename>

To find what package owns the command, try:

dpkg -S `which <command>`

For further details, see article Find out if package is installed in Linux and dpkg cheat sheet.

回答2:

To be a little more explicit, here's a bit of bash script that checks for a package and installs it if required. Of course, you can do other things upon finding that the package is missing, such as simply exiting with an error code.

PKG_OK=$(dpkg-query -W --showformat='${Status}\n' the.package.name|grep "install ok installed")
echo Checking for somelib: $PKG_OK
if [ "" == "$PKG_OK" ]; then
  echo "No somelib. Setting up somelib."
  sudo apt-get --force-yes --yes install the.package.name
fi

If the script runs within a GUI (e.g. it is a Nautilus script), you'll probably want to replace the 'sudo' invocation with a 'gksudo' one.

回答3:

This one-liner returns 1 (installed) or 0 (not installed) for the 'nano' package..

$(dpkg-query -W -f='${Status}' nano 2>/dev/null | grep -c "ok installed")

even if the package does not exist / is not available.

The example below installs the 'nano' package if it is not installed..

if [ $(dpkg-query -W -f='${Status}' nano 2>/dev/null | grep -c "ok installed") -eq 0 ];
then
  apt-get install nano;
fi

回答4:

I offer this update since Ubuntu added its "Personal Package Archive" (PPA) just as this question was answered, and PPA packages have a different result.

1. Native Debian repository package not installed:

   ~$ dpkg-query -l apache-perl
   ~$ echo $?
   1
   

2. PPA package registered on host and installed:

   ~$ dpkg-query -l libreoffice
   ~$ echo $?
   0
   

3. PPA package registered on host but not installed:

   ~$ dpkg-query -l domy-ce
   ~$ echo $?
   0
   ~$ sudo apt-get remove domy-ce
   [sudo] password for user: 
   Reading package lists... Done
   Building dependency tree       
   Reading state information... Done
   Package domy-ce is not installed, so not removed
   0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
   

Also posted on: https://superuser.com/questions/427318/test-if-a-package-is-installed-in-apt/427898

回答5:

UpAndAdam wrote:

However you can't simply rely on return codes here for scripting

In my experience you can rely on dkpg's exit codes.

The return code of dpkg -s is 0 if the package is installed and 1 if it's not, so the simplest solution I found was:

dpkg -s <pkg-name> 2>/dev/null >/dev/null || sudo apt-get -y install <pkg-name>

Works fine for me...

回答6:

This seems to work pretty well.

$ sudo dpkg-query -l | grep <some_package_name> | wc -l

• It either returns 0 if not installed or some number > 0 if installed.

回答7:

I've found all solutions above can produce a false positive if a package is installed and then removed yet the installation package remains on the system.

To replicate: Install package apt-get install curl
Remove package apt-get remove curl

Now test above answers.

The following command seems to solve this condition:
dpkg-query -W -f='${Status}\n' curl | head -n1 | awk '{print $3;}' | grep -q '^installed$'

This will result in a definitive installed or not-installed

回答8:

$name="rsync"

[ `which $name` ] $$ echo "$name : installed" || sudo apt-get install -y $name

回答9:

This will do it. apt-get install is idempotent.

sudo apt-get install command

回答10:

Use:

apt-cache policy <package_name>

If it is not installed, it will show:

Installed: none

Otherwise it will show:

Installed: version

回答11:

I've settled on one based on Nultyi's answer:

MISSING=$(dpkg --get-selections $PACKAGES 2>&1 | grep -v 'install$' | awk '{ print $6 }')
# Optional check here to skip bothering with apt-get if $MISSING is empty
sudo apt-get install $MISSING

Basically, the error message from dpkg --get-selections is far easier to parse than most of the others, because it doesn't include statuses like "deinstall". It also can check multiple packages simultaneously, something you can't do with just error codes.

Explanation/example:

$ dpkg --get-selections  python3-venv python3-dev screen build-essential jq
dpkg: no packages found matching python3-venv
dpkg: no packages found matching python3-dev
screen                                          install
build-essential                                 install
dpkg: no packages found matching jq

So grep removes installed packages from the list, and awk pulls the package names out from the error message, resulting in MISSING='python3-venv python3-dev jq', which can be trivially inserted into an install command.

I'm not blindly issuing an apt-get install $PACKAGES because as mentioned in the comments, this can unexpectedly upgrade packages you weren't planning on; not really a good idea for automated processes that are expected to be stable.

回答12:

This feature already exists in Ubuntu and Debian, in the command-not-found package.

回答13:

apt list [packagename]

seems to be the simplest way to do it outside of dpkg and older apt-* tools

回答14:

For Ubuntu, apt provides a fairly decent way to do this. Below is an example for google chrome:

apt -qq list google-chrome-stable 2>/dev/null | grep -qE "(installed|upgradeable)" || apt-get install google-chrome-stable

I'm redirecting error output to null because apt warns against using its "unstable cli". I suspect list package is stable so I think it's ok to throw this warning away. The -qq makes apt super quiet.

回答15:

which <command>
if [ $? == 1 ]; then
    <pkg-manager> -y install <command>
fi

回答16:

This command is the most memorable:

dpkg --get-selections <package-name>

If it's installed it prints:

<package-name> install

Otherwise it prints

No packages found matching <package-name>.

This was tested on Ubuntu 12.04.1 (Precise Pangolin).

回答17:

Many things has been told but for me simplest way is:

dpkg -l | grep packagename

回答18:

I had a similar requirement when running test locally instead of in docker. Basically I only wanted to install any .deb files found if they weren't already installed.

# If there are .deb files in the folder, then install them
if [ `ls -1 *.deb 2> /dev/null | wc -l` -gt 0 ]; then
  for file in *.deb; do
    # Only install if not already installed (non-zero exit code)
    dpkg -I ${file} | grep Package: | sed -r 's/ Package:\s+(.*)/\1/g' | xargs dpkg -s
    if [ $? != 0 ]; then
        dpkg -i ${file}
    fi;
  done;
else
  err "No .deb files found in '$PWD'"
fi

I guess they only problem I can see is that it doesn't check the version number of the package so if .deb file is a newer version, then this wouldn't overwrite the currently installed package.

回答19:

In Bash:

PKG="emacs"
dpkg-query -l $PKG > /dev/null || sudo apt install $PKG

Note that you can have a string with several packages in PKG.