fiji-archive-status.sh

#!/bin/bash

# Emits 'up-to-date' if a Fiji app bundle has been created since
# the most recent update to the core ImageJ/Fiji update sites,
# and 'update-needed' otherwise.

. "${0%/*}/common.include"

case "$track" in
  latest) sites='sites.imagej.net/Fiji' ;;
  stable) sites='update.imagej.net update.fiji.sc sites.imagej.net/Java-8' ;;
esac

DATE=date
if [ "$(uname)" = 'Darwin' ]
then
  which gdate >/dev/null || {
    echo 'This script requires GNU date, but macOS uses BSD date.'
    echo "Please install GNU date via 'brew install coreutils'."
    exit 1
  }
  DATE=gdate
fi

# -- helper methods --

# convert timestamp strings to numeric values for easier comparison
convert_time () {
  datenum=$($DATE --date="$1" '+%s')
  echo "$datenum"
}

# get the last modified date of a given url as seconds sinch the epoch
get_modified_date () {
  result=$(curl -Ifs "$1" | grep '^Last-Modified:')
  datestamp=${result#*, }
  dateval=$(convert_time "$datestamp")
  echo "$dateval"
}

# get the most recent modification date from among the core ImageJ/Fiji update sites
update_site_modified () {
  update_site_times=()
  for repo in $sites; do
    dateval=$(get_modified_date "https://$repo/db.xml.gz")
    update_site_times+=("$dateval")
  done

  # Just use the most recent modified date from among the update sites
  sorted=($(printf "%s\n" ${update_site_times[@]} | sort -r))

  echo "${sorted[0]}"
}

# get the most recent modification date of a selected fiji bundle
fiji_bundle_modified () {
  dateval=$(get_modified_date "https://downloads.imagej.net/fiji/$track/$fiji_nojava.zip")
  echo "$dateval"
}

# -- program entry point --

if [ "$(update_site_modified)" -gt "$(fiji_bundle_modified)" ]; then
  echo 'update-needed'
else
  echo 'up-to-date'
fi