Install telegram into rpm based system

telegram.sh

#!/bin/bash
# http://stackoverflow.com/questions/5947742/how-to-change-the-output-color-of-echo-in-linux
RED='\033[0;31m'
NC='\033[0m' # No Color


printf "${RED}Check&install required utility${NC}\n"
rpmqa=`rpm -qa`
echo $rpmqa | grep -qw wget || sudo dnf install wget
echo $rpmqa | grep -qw tar || sudo dnf install tar

bit="32"
if [ `uname -m` == "x86_64" ]; then
   bit="64"
fi
printf "${RED}We detected $bit system${NC}\n"

printf "${RED}Download&Install${NC}\n"

if [ $bit == "64" ]; then
  bit=""
fi

download_url="https://tdesktop.com/linux${bit}"
sudo wget --progress=bar:force -O /opt/telegram.tar.xz $download_url
sudo wget -O /opt/Telegram/Telegram.png https://telegram.org/img/t_logo.png
sudo tar -xJvf /opt/telegram.tar.xz -C /opt
sudo rm /opt/telegram.tar.xz

printf "${RED}Desktop icon${NC}\n"

cat > ~/.local/share/applications/telegram.desktop << EOF
[Desktop Entry]
Type=Application
Encoding=UTF-8
Name=Telegram
Comment=Telegram
Exec=/opt/Telegram/Telegram
Icon=/opt/Telegram/Telegram.png
Terminal=false
EOF

printf "${RED}Done. Feel free to use${NC}\n"

/opt/Telegram/Telegram &> /dev/null &