A script that runs simultaneously a curl GET command and returns the http status code of a list of addresses.

parallel_curl.sh

#!/bin/bash
readonly ARGC=$#
readonly ARGV=( "$@" )

readonly PROG_NAME=$(basename "$0")

usage()
{
    echo "Usage: $PROG_NAME <url-list>"
    exit 1
}

gather_addresses()
{
    local file="$1"
    local addresses=()
    
    while read -r address ; 
    do
        addresses+=( "$address" )
    done < "$file"

    echo "${addresses[@]}"
}

curl_it()
{
    local url="$1"
    local cmd="curl "$url""
    $cmd
}

parallel_curl()
{
    export -f curl_it
    local addresses="$1"
    
    parallel curl_it :::: $addresses
}

main()
{
    if [ "$ARGC" -gt 0 ] ;
    then
        local file
        for file in $ARGV ; 
        do 
            [[ -f "$file" ]] && parallel_curl $file 
        done 
    else
        usage
    fi   
}

main