Mongo: Get list of databases with a UNIX command

Question

I would like to get the list of the database manage by on server through a single shell command, on UNIX. The objective is to be able to do a full export of all dbs for validation purposes.
Right now, I can see only two ways to do this.
- Start mongo, type show dbs, to a manual copy of the list and exit. I do not like this way as this requires several manual operations.
- Scan the files.*.0 in the db directory.
This works but is dependent on the format of the database.Is there any better way to list all the DBs managed by a server through a single command? I am using MongoDB 3.0.4 on Scientific Linux.

Answer 1

Yes,
Step 1: Save this script in file ShowAllDBNames.js where mongodb exe is,

db.adminCommand('listDatabases').databases.
     filter(function(it)
    {return it.name != "local";
    }).
     forEach(function(it){print(it.name);
 })

Step 2:
then write this command and execute:

mongo --quiet ShowAllDBNames.js