#!/bin/bash

prefix='a_'

mkalias_with_prefix()
{
    alias ${prefix}$1="$1"
}

ask_continue()
{
    read -p "Продолжить [Y/n]?:" answ 
    if [[ "${answ}" == "n" || "${answ}" == "N" ]]; then 
        echo "Отменено" 
        return 0
    fi
    return 1
}

mkvar()
{
    # на входе 'var_name|val|def_val|string_to_print_before_return'
    p="$1"
    readarray -d "|" -t cur_params <<< "$p"
    var_name="${cur_params[0]}"
    val="${cur_params[1]}"
    def_val="${cur_params[2]}"
    string_to_print_before_return="${cur_params[3]}"

    if [ "${string_to_print_before_return}" == "" ]; then
        echo "$var_name=$val; [[ \"\${$var_name}\" == \"\" ]] && $var_name=$def_val;"
    else
        echo "$var_name=$val; [[ \"\${$var_name}\" == \"\" ]] && printf \"${string_to_print_before_return}\\n\" && return;"
    fi
}