function usage {
        echo "Usage: ${O##*/} <host> <date_debut> (format: \"%Y-%m-%d %H:%M:%S\")> <date_fin> \"<commentaire>\""
        echo " format dates: \"%Y-%m-%d %H:%M:%S\""
        echo " ex: nagios_downtime_w_childs.sh switch1 \"2021-01-15 07:18:00\" \"2021-01-15 07:48:00\" \"test downtime 30min\""
        exit 1
        }

[ -z "$4" ] && usage

now=$(date +%s)
commandfile='/var/nagios/rw/nagios.cmd'

# affectation et contrôle des inputs
naghost=$1
debut=$(date -d "$2" +%s 2>/dev/null)
[ -z "$debut" ] && { echo "Date début $2 invalide !"; usage; }
#[[ "$3" =~ ^[0-9]*$ ]] && fin=`expr $debut + $3` || { echo "ERR: Durée $3 invalide !"; usage; }
fin=$(date -d "$3" +%s 2>/dev/null)
[ -z "$fin" ] && { echo "Date fin $3 invalide !"; usage; }
comment="$4"

/usr/bin/printf "[%lu] SCHEDULE_AND_PROPAGATE_HOST_DOWNTIME;$naghost;$debut;$fin;1;0;7200;toto;$comment\n" $now > $commandfile