#! /bin/bash
#usage team_up.sh FILE

[[ $# -eq  0 ]]  && printf "\nERROR: You must provide a file for the script to work.\n\n" 1>&2 && exit 1

readarray -t names < <(sort -R $1) #create an array with each line of the file; -t strips the new line character
max=0 #used for proper formatting later in the script

for ((i=0; i<${#names[@]}; i+=2)) #i as in index; this way we get the even line numbers.
do
    if ((${#names[i]} > max)); then
        max=${#names[i]}
    else
        max=$max #get the string lenghth of the longest name. Usage later in printf.
    fi
done

for ((i=0; i<${#names[@]}; i+=2)); do
    printf -- "%-${max}s %s\n" "${names[i]}" "${names[i+1]}" #i+1, this way we get the odd line numbers
done