Выберите один из вариантов в bash

Я не пробовал это с gem uninstall bundler, но это может сработать для вас.

#launch your process in a subshell and direct the subshell output to a file
#yours will probably read (gem uninstall bundler -x) > count &

(echo title; echo "empty line"; echo "1. option"; echo "2. option" ; echo "3. All Versions"; sleep 10 ) > count &

pid=$!                                  #get the pid of the subshell
disown                                  #to avoid the untidy kill output
sleep 1                                 #just allow time for the subshell output
kill -9 $pid                            #kill the dummy process
option=$(grep -i "all versions" count | grep -Po "[^0-9]*[0-9]+")  
                                        #grab the option want from the output
rm count                                #tidy up
echo $option | gem etc....        #launch gem with the known option