Grouping two files into one custom file-type

Question

I am currently working on a simple tower defense game for iOS (using objective-c), which contains several maps/levels. However, as it is now, each map consists of an image file and a .plist file with information. My question is: is there any way I could create a custom file type (for example, *.map) that contains both the image and the information from the plist?

If this is possible, how do I implement this?

Thanks in advance!

Answer 1

You have several good choices for that:

• The simplest solution would be grouping the related files in subfolders: rather than having xyz.map file, you could have an xyz sub-folder, and reference the files out of it. You would not need to use any additional libraries for this, and you would be able to use the same name for all your image files and all your level files, because they would be in separate folders.
• You can make a zip archive with the files that you would like to combine, and unzip it before use. Here is a link to an answer referencing a library to do it.
• You can use a tar format - here is a list to an answer referencing a library that supports it. You would be able to use tar utility on OS-X to group images with plists on your workstation.
• Finally, you can define a format of your own: store the length of the first file in the first four bytes, then store the content of the first file, and then the second. You would need to write a utility for combining the two files into one. This sounds like the hardest choice to implement.