Displays content from /var/log/apt/history* in a table format (similar to yum history)

apt-history.sh

function apt-history() {
  local install_date login_user command type changed usage

  usage="apt-history - Displays content from /var/log/apt/history* in a table format (similar to yum history)"
  if [ $# -gt 0 ] && [[ "$1" == "-h" ]] ; then
      echo "$usage"
      return 0
  elif [ $# -gt 0 ] ; then
    echo "This function does not accept options"
    return 1
  fi


  # Make sure we are root
  if [[ $(id -u) -ne 0 ]] ; then
    echo "You need to be root"
    return 1
  fi

  # Makes sure log folder exists
  if [ ! -d /var/log/apt ] ; then
    echo "Missing the APT log folder"
    return 1
  fi

  apt_history_files="$(find /var/log/apt -name 'history*' | xargs ls -tr)"
  {
    echo " ID | Login user | Date and time | Command | Type | Altered |"
    echo " -- | ---------- | ------------------ | ----------------- | ------- | ------- |"

    for file in $apt_history_files ; do
      if echo "$file" | grep -q gz ; then
        cat_cmd="zcat"
      else
        cat_cmd="cat"
      fi
      $cat_cmd "$file" | while read line ; do
        # Gets the install date
        if echo "$line" | grep -q 'Start-Date' ; then
          install_date="$(echo "$line" | grep 'Start-Date' | awk -F':' '{print $2 ":" $3}')"
        fi

        # Gets the command
        if echo "$line" | grep -q 'Commandline' ; then
          command="$(echo "$line" | grep 'Commandline' | awk -F':' '{print $2}' | awk '{print $1 , $2}')"
        fi

        # Gets the user
        if echo "$line" | grep -q 'Requested-By:' ; then
          login_user="$(echo "$line" | grep 'Requested-By:' | awk -F':' '{print $2}' | awk '{print $1}')"
        fi

        # Gets the installed files
        if echo "$line" | grep -q 'Install' ; then
          type="Install"
          changed="$(echo "$line" | grep 'Install' | sed 's/),/)|/g' | tr '|' '\n' | wc -l)"
        fi

        if echo "$line" | grep -q 'Upgrade:' ; then
          type="Upgrade"
          changed="$(echo "$line" | grep 'Upgrade:' | sed 's/),/)|/g' | tr '|' '\n' | wc -l)"
        fi

        if echo "$line" | grep -q 'Remove:' ; then
          type="Remove"
          changed="$(echo "$line" | grep 'Remove:' | sed 's/),/)|/g' | tr '|' '\n' | wc -l)"
        fi
        
        # Outputs on end of block
        if echo "$line" | grep -q 'End-Date:' ; then
          # Fixes blank username
          if [ ! "$login_user" ] ; then
            login_user="system"
          fi

          echo " $login_user | $install_date | $command | $type | $changed | "
          unset install_date login_user command type changed
        fi
      done
    done | nl -s "|" | sort -r -t "|" -k1
  } | sed 's/|/,|,/g' | column -s "," -t | less
}