Bash script to automatically and smartly update PaperMC whenever a new version is available. You need to install `jq` and `wget`.

update.sh

#!/bin/bash

# set a target minecraft major version
target_mc_version=1.19

# retrieve the latest minecraft minor version
latest_mc_version=$(curl "https://api.papermc.io/v2/projects/paper" | jq -r '[.versions[] | select(. | test("^'$target_mc_version'"))] | last')

# retrieve the matching latest paper version
latest_paper_version=$(curl "https://api.papermc.io/v2/projects/paper/versions/${latest_mc_version}" | jq -r '[.builds[]] | last')

# check if the .mc_version file exists
if [ -a .mc_version ]; then
    # if the file exists, find the currently installed version of paper
    current_paper_version=$(cat .mc_version)

    # if the currently installed version matches the version, no need to update
    if [ "$current_paper_version" == "$latest_paper_version" ]; then
        # inform the user that we are not updating the jar
        echo "paper is already up-to-date"

        # return without error
        exit 0
    fi
fi

# delete the existing har
rm -rf paper.jar

# download the new jar
wget "https://api.papermc.io/v2/projects/paper/versions/${latest_mc_version}/builds/${latest_paper_version}/downloads/paper-${latest_mc_version}-${latest_paper_version}.jar"

# move the jar 
mv "paper-${latest_mc_version}-${latest_paper_version}.jar" paper.jar

# update the .mc_version
echo $latest_paper_version > .mc_version

# inform the user that we updated the jar
echo "downloaded the new paper version"

# return without error
exit 0

Why rm -rf? Isn't that unnecessarily dangerous? Just use rm without flags, you're removing one jar.

You are right about the recursive part, but I think if you don’t use -f it will ask you to remove it and you might get errors, which makes the auto-update aspect kind of pointless. I used -rf out of reflex to be absolutely sure it cleans it well, the je is public anyway, it’s not like it’s valuable.

By the way how did you end up on that script ? It’s kind of lost on the web 😅.

Haha I literally just Google'd paper update bash and found this!

Ah I suppose force is fine, it typically won't ask if it should be removed or not either way, unless it's had the write permissions removed (which I assume would usually be explicitly/intentionally done).