How to put apt and python packages in a list and check if installed or not then install

Question

I am not an expert in shell scripting,

I need help optimizing the shell script I wrote, This shell script I wrote is run by users on the client side who connect to our vpn server from the setting passed in the config.tar.

I check if pip or or tar or other packaches are installed if not isntalled than install it, I am doing it in separate if condition, what I want to achieve is I put the packages to check in a listand then iterate if not installed than install it for all apt, pip or pip3 packages.

#!/usr/bin/env bash 
set -
command=`which pip`
if [ "$command" = "" ]
then
 echo "The pip program not exist on this system."
 sudo apt-get install python-pip -y
 sudo apt install python3-pip -y
else
 echo "Pip is intalled."
fi
sudo apt install speedtest-cli
pip install -U pip
pip3 install mysql-connector-python
pip3 install pymysql
pip3 install sqlalchemy
TAR=`which tar`
if [ "$TAR" = "" ]
then
 echo "Tar is not installed, installing now."
 sudo apt-get install tar -y
else
 echo "Tar is installed."
fi
# lets install requests 
pip install requests
cd $HOME
echo "Iniating download..."
curl -sL "http://my.domain.com/config" -o "config.tar"
tar xvf config.tar
sudo chmod 604 ucc.py 
if [ -e ucc.py ]
then
 echo "ucc.py installed."
else
 echo "ucc.py failed to download."
fi
if [ -e ucc.service ]
then
 echo "ucc.service installed."
else
 echo "ucc.service failed to download."
fi
sudo mv ucc.service "/lib/systemd/system/"
if [ -e client.conf ]
then
 sudo mv client.conf /etc/openvpn/
 echo "client.conf downloaded."
else
 echo "client.conf failed to download."
fi
sudo mv -f client.conf /etc/openvpn/
cd /etc/openvpn/
if [ -e client.conf ]
then
 echo "client.conf installed."
else
 echo "client.conf failed to download."
fi
sudo systemctl restart openvpn@client
sudo systemctl status openvpn@client

any help will be greatly appreciated.

• Ted Brownlow: For the apt-get install, why not just run the install command? Nothing bad should happen from attempting to install a package that already exists
• Chang Zhao: thats because on client side end user is non-technical person

Answer 1

1. Use for loops for expandability and readability.
2. If you want to test for individual utilities, try using command -v pip instead of which and comparing against that.
3. Look up and understand the functional difference between single bracket comparisons and double bracket. [ ] vs [[ ]]
4. `` syntax is very out of date, use $()
5. If you have to call /usr/bin/env for the location of bash, but broadly assume apt is the package manager on the system, it's much safer to use /bin/bash.
6. Python requests is also stored as an apt package, I moved it into the first for loop statement.

#!/bin/bash
for PACKAGE in python-pip python-pip3 speedtest-cli tar python-requests; do
 if [[ ! $(dpkg -l ${PACKAGE}) ]] ; then
 echo "${PACKAGE} is not installed, installing now."
 sudo apt-get install ${PACKAGE} -y
 else
 echo "${PACKAGE} is installed."
 fi
done
pip3 install -U pip
for PACKAGE in mysql-connector-python pymysql sqlalchemy ; do
 pip3 install -U ${PACKAGE}
 if [[ $? -ne 0 ]] ; then echo "${PACKAGE} failed to installed" ; fi
done
cd $HOME
echo "Iniating download..."
curl -sL "http://my.domain.com/config" -o "config.tar"
tar xvf config.tar
sudo chmod 604 ucc.py
## I don't know why you need to use sudo to chmod an item inside your own home dir, but ill leave this here.
## Also, you can tar a package with certian perms and then unpack it to obey those specific permissions.
for ITEM in ucc.py ucc.service client.conf; do
 if [[ -e ${ITEM} ]] ; then
 echo "${ITEM} is installed."
 else
 echo "${ITEM} failed to download"
 fi
done
sudo mv ucc.service /lib/systemd/system/
sudo mv client.conf /etc/openvpn/
sudo mv -f client.conf /etc/openvpn/
sudo systemctl restart openvpn@client
sudo systemctl status openvpn@client

• Chang Zhao: do you mean if i set the file permission and tar it on extraction those permission attributes will be preserved?
• Arlion: @ChangZhao askubuntu.com/questions/463325/…