导出索引的脚本（ 兼容了唯一索引，和超时配置）

var collectionList = db.getCollectionNames();
for(var index in collectionList){
var collection = collectionList[index];
var cur = db.getCollection(collection).getIndexes();
if(cur.length == 1){
continue;
}
for(var index1 in cur){
var next = cur[index1];
if(next["key"]["_id"] == '1'){
continue;
}
print(
"try{ db.getCollection(\""+collection+"\").ensureIndex("+JSON.stringify(next.key)+",{background:1, unique:" + (next.unique || false) + "" + (next.expireAfterSeconds > 0 ? ", expireAfterSeconds :" + next.expireAfterSeconds : "") + " })}catch(e){print(e)}")}}