You want to read data from a CSV file and import into mongodb? You could generate a script file (javascript) and use the mongo shell to execute it like described in "scripting the shell".
Example session, test database, starting with an empty foo collection:
> db.foo.insert({name : "james", position : "forward"})
> db.foo.find()
{ "_id" : ObjectId("4f0c99f6cb435f1e7d7fedea"), "name" : "james", "position" : "forward" }
>
then you generate your script let's say mongo_scripting.js:
db.foo.insert({name : "wade", position : "guard"});
db.foo.update({name : "james"}, {$set : {position : "power forward"}}, false, true);
and running the script:
mongo localhost:27017/test mongo_scripting.js
going back to mongo:
> db.foo.find()
{ "_id" : ObjectId("4f0c99f6cb435f1e7d7fedea"), "name" : "james", "position" : "power forward" }
{ "_id" : ObjectId("4f0c9a64a4a4642bae6459ea"), "name" : "wade", "position" : "guard" }
>
you see that one document got updated and one new inserted.
An alternative is to use the java/python... driver to load the data.