Can I convert a dmg file to iso in terminal?

Follow the steps below.

Just press Ctrl+Alt+T on your keyboard to open Terminal. When it opens, run the command(s) below:

sudo apt-get install dmg2img

Once installed, run the following command:

dmg2img <file_name>.dmg

That will convert the .dmg to ,img file in ISO format. Then just run

mv <file_name>.img <file_name>.iso

In order to convert the dmg to iso you need:

1) Convert the dmg to img using dmg2img

you can install it using: sudo apt-get install dmg2img

Then (if your dmg is named image.dmg in the current folder):

dmg2img image.dmg image.img

2) To mount the img

mkdir /media/image

sudo modprobe hfsplus

sudo mount -t hfsplus -o loop image.img /media/image

3) To burn the files in /media/image coming from the mount to an iso file:

You may use brasero for that step. You can install it using:

sudo apt-get install brasero

Detailed instructions can be found there: http://dailytechnologiesupdate.blogspot.co.il/2011/11/converting-dmg-to-iso-file-in-ubuntu.html