Chatty curl to output file with cheap argument host validation, no usefull usage instructions, and hardcoded output file name, pretty rudimentery code.

check_url.sh

#! /bin/sh

function check {
        if [ $? -ne 0 ] ; then
                echo "Error occurred getting URL $1;"
                if [ $? -eq 6 ]; then
                        echo "Unable to reslove host"
                fi
                if [ $? -eq 7 ]; then
                        echo "Unable to contact host"
                fi
                exit 1
        fi
}
curl -s -o "check_out001.txt" $1
check;
echo 'got it'