#Rails 4.2: How to create a full URL with given host and port

Basically if you need to generate url based on the current url during a request OR you can create your own Urls by using Rails ‘ActionDispatch::Integration::Session‘ class.

Rails creates an object ‘app’. It is and action dispatch session object.

You can make use of that object for creating your own URLs like:

> app.root_url(:port => 20)
=> "http://www.example.com:20/"

> app.root_url(:port => 20, :host => 'www.bing.com')
=> "http://www.bing.com:20/"

During a request you can use like this:

> request.url(:port => 20)


Create bootable usb drive of OSX from Mac OS

You can use mac’s createinstallmedia command. The format to create a bootable USB is given below.

$ sudo /Applications/Install\ macOS\ Sierra.app/Contents/Resources/createinstallmedia --volume |YOUR-USB-DRIVE-PATH-HERE| --applicationpath |DOT-APP-FILE-MACOS|

In My system the command will be as follows:

$ sudo /Applications/Install\ macOS\ Sierra.app/Contents/Resources/createinstallmedia --volume /Volumes/ABHI\'S/ --applicationpath /Applications/Install\ macOS\ Sierra.app/

You can easily find the corresponding software path in your system, if you have a different OS that mentioned above.

For more details, visit:

Mongodb how to Import / Export in Linux/Mac

For Importing a mongodb use the following command

$ mongodump --db database_name

This will dump the json/bson files into dump/db_name folder
Or specify a directory with -o option

$ mongodump --db database_name -o path_to_folder

By specifying username and password

$ mongodump --db database_name -o /path/to/folder/ --username=my_user --password="my_password"

For Exporting a mongodb use the following command

$  mongorestore --db database_name path_to_the_json_bson_files

path_to_the_json_bson_files => That we already imported and stored before.

    How to import only one document from a database and export into another database:

Import one document

$ mongodump --db=db_name --collection=collection_name --out=path_to_folder_to_import
$ mongorestore --db=new_db_name --collection=collection_name path_to_folder_to_import/db_name/collection_name.bson