check.sh

#!/bin/bash
# Config
onlineUrls="online.txt"
offlineUrls="offline.txt"
arrayLimit=200
parallelInstances=20
curlTimeout=1

truncate -s0 "$onlineUrls" "$offlineUrls"

# Check der URLs
checkUrls() {
    while read line; do
        if curl -Ls --connect-timeout "$curlTimeout" "$line" &> /dev/null; then
            online+=("$line")
            if [[ ${#online[@]} -eq $arrayLimit ]]; then
                printf "%s\n" "${online[@]}" >> "$onlineUrls"
                online=()
            fi
        else
            offline+=("$line")
            if [[ ${#offline[@]} -eq $arrayLimit ]]; then
                printf "%s\n" "${offline[@]}" >> "$offlineUrls"
                offline=()
            fi
        fi
    done < "$1"

    printf "%s\n" "${online[@]}" >> "$onlineUrls"
    printf "%s\n" "${offline[@]}" >> "$offlineUrls"
}

# Parsing
rm "${1%.*}"[[:digit:]]* 2> /dev/null
splitLength=$(( $(wc -l "$1" | cut -d ' ' -f1) / $parallelInstances ))
split -da8 -l"$splitLength" "$1" "${1%.*}"

online=()
offline=()

for file in "${1%.*}"[[:digit:]]*; do
    checkUrls "$file" &
done

while jobs -r | grep checkUrls &> /dev/null; do
    sleep 1
done

sed -i '/^$/d' online.txt offline.txt