awk

    Prepend string to each line

    echo "world" | awk '{print "hello " $0}'
    hello world
    

    Get the ith element (separated by tabs/space)

    cat file | awk '{print $2}'
    

    Note: here its for the second element

    Get the element according to a regex

    echo "total 500K othter stuff" | awk '/[0-9]K/{print $2}'
    # 500K