How to create a disk image from the command line

Question

Currently part of my build process is as follows;

• Start Utilities/Disk Utility
• Select New Image
• Set Save As to widget
• Set Name to widget
• Set Size to custom size 50 mb
• Set Format Mac OS Extended

but is it possible to do all this from the command line ?

Answer 1

You can do this with the hdiutil tool. The appropriate configuration in your case would be:

hdiutil create -size 50m -fs HFS+ -volname Widget /path/to/save/widget.dmg

Obviously change the "Widget" and path to whatever you need.

A few additional options that may be useful:

• -srcfolder /path/to/source This will create the disk image with the data in the specified folder as the contents.
• -megabytes 50 used instead of -size 50m. This will use binary sized megabytes (2^20 bytes) instead of decimal (10^6 bytes).
• -srcdevice /dev/diskXsY This is like srcfolder, but makes a block-based copy from another device, like a hard drive partition or DVD. Useful for making clones and images of install disks, etc.