sleeptime=30
sleepinterval=3
while [ $sleeptime -gt 0 ]
do
	echo to wait $sleeptime seconds
	sleep $sleepinterval
	sleeptime=$[ sleeptime-sleepinterval ]
done

argv=$@
arglen=$#
echo $arglen
argstart=3
slice=${@:argstart}
#slice=${argv[@]:argstart:arglen+1-argstart} 只单个
echo $slice
for ch in $slice; do
    echo $ch
done

JOIN_PEER=(10 11 12 13)
echo ${JOIN_PEER[@]}
for ch in ${JOIN_PEER[@]}; do
    echo $ch len ${#ch}   #每个参数的字符长度
done
peerslice=${JOIN_PEER[@]:1:2}
echo $peerslice

declare -A hashmap
hashmap["key"]="value"
hashmap["key2"]="value2"
echo "${hashmap["key"]}"
for key in ${!hashmap[@]}; do echo $key; done
for value in ${hashmap[@]}; do echo $value; done
echo hashmap has ${#hashmap[@]} elements