A fast, `parallel` powered website status checking script.

are_my_damn_websites_alive.sh

#!/bin/bash
check="./check_host.sh"
logfile="lastrun.log"

debug=$1
 
if command -v parallel >/dev/null 2>&1; then # PARALLEL :D
    cat hosts | parallel --joblog $logfile -a - -j '1000%' "$check {} $debug"
else # NOT PARALLEL D:
    rm -f $logfile && touch $logfile
    for host in $(cat hosts); do
        [ "$host" == "" ] && continue
        $check $host $debug | tee -a $logfile
    done
fi

check_host.sh

#!/bin/bash -e
 
[ "$1" == "" ] && echo "$0 <hostname>" && exit 2
 
check_dns() {
    hostname=$1
    debug=$2
    if host $hostname >/dev/null; then :; else
        echo $hostname failed DNS lookup
        if [ "$debug" != "" ]; then
            dig +trace @8.8.8.8 $hostname
        fi
    fi
}
 
check_http() {
    hostname=$1
    debug=$2
    if curl -m 10 -LIs $hostname >/dev/null; then :; else
        echo $hostname failed HTTP request
        if [ "$debug" != "" ]; then
            curl -m 10 -sS -v -L $hostname
            curlcode=$?
            case $curlcode in
                7) # Failed to connect() to host or proxy
                    traceroute -n $hostname
                    ;;
            esac
        fi
    fi
}
 
check_dns $1 $2
check_http $1 $2

hosts

example.com
www.example.com