Discord Linux Installer/Updater for Discord tar (tgz)

DiscordInstaller.sh

#!/bin/bash
# Install/Update Discord
# v1
# Adam Boutcher - 2021 - IPPP, Durham Uni (UKI-SCOTGRID-DURHAM)

URL="https://discord.com/api/download?platform=linux&format=tar.gz"
LOC="/opt"

#Function: Check that a binary exists
#Usage: check_bin command
function check_bin() {
  which $1 1>/dev/null 2>&1
  if [[ $? -ne 0 ]]; then
    echo "$1 cannot be found. Please install it or add it to the path. Exiting."
    exit 1
  fi
}

check_bin which
check_bin echo
check_bin rm
check_bin mkdir
check_bin tar
check_bin curl
check_bin cat
check_bin awk
check_bin tr

if [ -d ${LOC}/Discord ]; then
  echo "Updating Discord - ${LOC}/Discord"
  curver=$(cat ${LOC}/Discord/resources/build_info.json | grep version | awk '{print $2}' | tr -d '"' 2>/dev/null)
  latver=$(curl -Ls ${URL} -w %{url_effective} -o /dev/null -I | awk -F '/' '{print $6}' 2>/dev/null)
  if [ $curver != $latver ]; then
    rm -rf ${LOC}/Discord >/dev/null 2>&1
    if [ $? -ne 0 ]; then
      echo "Cannot remove old Discord"
      exit 2
    fi
  else
    echo "Already Latest"
    exit 0
  fi
else
  echo "Installing Discord - ${LOC}/Discord"
fi

mkdir -p /tmp/discord_download/ >/dev/null 2>&1

if [ ! -d ${LOC} ]; then
  mkdir -p ${LOC} >/dev/null 2>&1
  if [ $? -ne 0 ]; then
    echo "Cannot create ${LOC}"
    exit 2
  fi
fi

curl -s -L ${URL} -o /tmp/discord_download/discord.tgz >/dev/null 2>&1
tar -xf /tmp/discord_download/discord.tgz -C ${LOC} >/dev/null 2>&1
if [ $? -ne 0 ]; then
  echo "Cannot extract Discord to ${LOC}"
  exit 2
fi

rm -rf /tmp/discord_download/ >/dev/null 2>&1

if [ ! -f /usr/share/applications/discord.desktop ]; then
  cat > /usr/share/applications/discord.desktop << EOF
[Desktop Entry]
Name=Discord
StartupWMClass=discord
Comment=All-in-one voice and text chat for gamers that's free, secure, and works on both your desktop and phone.
GenericName=Internet Messenger
Exec=${LOC}/Discord/Discord
Icon=${LOC}/Discord/discord.png
Type=Application
Categories=Network;InstantMessaging;
Path=/usr/bin
EOF

#update-desktop-database >/dev/null 2>&1
fi

Could make this test for root/userspace?