Gfilui

In a bash shell, if you put some command that is not installed on your system, it throws an error and also gives you a package installation suggestion. For example-

$ iostat

Command 'iostat' not found, but can be installed with:

sudo apt install sysstat

My personal favorite is tcsh but it does not give any package installation suggestion while some command is not found. How can I get the package installation suggestion (like bash) in tcsh?

The magic works because of command_not_found package that provide a command_not_found_handle function for both bash and zsh.

This works in bash because of this snippet in /etc/bash.bashrc

# if the command-not-found package is installed, use it
if [ -x /usr/lib/command-not-found -o -x /usr/share/command-not-found/command-not-found ]; then
 function command_not_found_handle 
 # check because c-n-f could've been removed in the meantime
 if [ -x /usr/lib/command-not-found ]; then
 /usr/lib/command-not-found -- "$1"
 return $?
 elif [ -x /usr/share/command-not-found/command-not-found ]; then
 /usr/share/command-not-found/command-not-found -- "$1"
 return $?
 else
 printf "%s: command not foundn" "$1" >&2
 return 127
 fi
 
fi

There is also a file /etc/zsh_command_not_found that you can source to get that behavior for zsh - here, the function is called command_not_found_handler.

From a quick search, it does not seem that tcsh include such a functionnality to define a command_not_found_handle. So may be the name, is different, in that case you just need to convert the snippet in tcsh and include it in your ~/.tcshrc, else you can't!