pingコマンドの結果をログファイルに収集する

#!/bin/sh
#autoping.sh

logfile='ping.log'

if [ -z "$1" ]; then
    echo "Usage: autoping.sh hostname [hostname...]"
    exit 9
fi

daytime="`date +"%b %d %H:%M:%S"` "

while [ -n "$1" ]; do
    if ping -c 1 $1 > /dev/null; then
        echo "$daytime PING is reachable. Host \"$1\" may be alive." >> $logfile
    else
        echo "$daytime PING is NOT UNREACHABLE. \"$1\" may NOT BE AVILE." >> $logfile
    fi
    shift
done