Using && and || to check installed tools-CodePudding

I am testing if someone tools is installed in the system with command

In this case I am checking if unzip is installed. if unzip is installed the nothing happend but if unzip is not installed, the script will run apt-get update and apt-get install unzip.

All this I prefer run it in one all.

I am trying this command:

command -v unzip && echo "[ ] unzip is installed in the system" || echo "[!] unzip is not installed in the system" && apt-get update && apt-get install unzip

With that command always I am installing unzip.

How can i do to install unzip ONLY if unzip is not installed?

Thank you

CodePudding user response：

To group between logical statements, you need to enclose them in curly braces. The syntax is like this { ... ; }.

$ command -v bash &>/dev/null && echo 'Installed' || { echo 'Not installed' && echo "Please dont" && echo 'Yes, please do'; }
Installed

$ { command -v bash &>/dev/null && echo 'Installed'; } || { echo 'Not installed' && echo "Please dont" && echo 'Yes, please do'; }
Installed

$ command -v notexist &>/dev/null && echo 'Installed' || { echo 'Not installed' && echo "Please dont" && echo 'Yes, please do'; }
Not installed
Please dont
Yes, please do

$ { command -v notexist &>/dev/null && echo 'Installed'; } || { echo 'Not installed' && echo "Please dont" && echo 'Yes, please do'; }
Not installed
Please dont
Yes, please do

Note: A semicolon ; before the closing braces is important.