This is a small script that tries to intelligently download plantuml and keep it up-to-date. It also exposes some functions to generate svgs and pngs.

planthelpers.sh

#!/bin/bash

tool_dir=$(dirname $0)
scriptpath="$( cd -- "$(dirname "$0")" >/dev/null 2>&1 ; pwd -P )"
plant="$tool_dir/plantuml.jar"

function log {
   if [ "$DEBUG" == "true" ]; then
       echo "$@"
   fi
}

function getplant {
    # First check the modified date to see if the file is older than 10 days.

    # Doing time calculations here which are a bit of a cluster. The point of the calculation
    # is to find out if this file is 10 days old. I'm accomplishing that by getting the
    # modified_time of the plant file (seconds) and subtracting that from "now".
    # Next, I compare that diff to to see if it is less than the amount of seconds
    # in 10 days. "time_diff" will get bigger as time increases.
    modified_time=$(stat -c '%Y' "$plant")
    log "modified_time: $modified_time"
    time_diff=$((`date +%s`-$modified_time))
    log "time_diff: $time_diff"
    if [ "$time_diff" -lt $((60 * 60 * 24 * 10)) ]; then
       log "Recent version, no need to check"
       return 0
    fi

    # If the jar is older than 10 days, check the md5 locally against sourceforge.
    md5=''
    if [ -f "$plant" ]; then
        md5=$(md5sum "$plant" | cut -d ' ' -f1)
    fi
    log $md5
    json=$(curl -s 'https://sourceforge.net/projects/plantuml/best_release.json')
    # Grabbing the linux release but it should work for macos too
    newmd5=$(jq -r '.platform_releases.linux.md5sum' <<< $json)
    log $newmd5
    if [ "$md5" == "$newmd5" ] || [ -z "$newmd5" ]; then
        # Bail if the md5 matches or we don't get an md5 from sourceforge
        log "same file, bailing"
        return 0
    fi
    url=$(jq '.platform_releases.linux.url' <<< $json)
    log "download url: $url"
    curl -L -s -o "$plant" "$url"
}

function find_git {
   echo "$(git rev-parse --show-toplevel)"
}

function make_svgs {
   toplevel=$(find_git)
   find $toplevel -type f -name '*.puml' -exec java -jar "$plant" {} -tsvg \;
}

function make_pngs {
   toplevel=$(find_git)
   find $toplevel -type f -name '*.puml' -exec java -jar "$plant" {} -tpng \;
}

case "$1" in
    "") ;;
    getplant) getplant; exit;;
    make_pngs) make_pngs; exit;;
    make_svgs) make_svgs; exit;;
    *) echo "Unkown function: $1"; exit 2;;
esac