#JSRUN引擎2.0，支持多达30种语言在线运行，全仿真在线交互输入输出。
a="1008234";
#echo "$a"|[ -n "`sed -n '/^[0-9][0-9]*$/p'`" ] && echo string a is numbers+echo “$a is num”
echo "$a is"

if ["$a"|[ -n "`sed -n '/^[0-9][0-9]*$/p'`" ]] ; then

echo "$a is num"

fi