framework in ios contain static or dynamic library inside

Question

I have come across multiple sites describing that frameworks can contain both static as well as dynamic library. But how do I identify if what the framework actually contain

Answer 1

To answer first part of your question, Yes, your understanding is correct that a Framework is just a Directory Structure that bundles the library image (Compiled machine code, headers, resources etc.). To verify if the Framework is actually a Static Library or Dynamic Use the following command

file Path/To/YourLib.framework/YourLib

If the output of a particular architecture (armv7, arm64 etc) says ar archive its a Static Library, on the other hand if for any architecture it says dynamically linked shared library then its unsurprisingly a dynamic library.

If you are creating a Framework Project yourself, You can choose to build a Static or Dynamic Image by setting the Mach-O Type Build Setting of your project.

There are different possibilities in case a same Symbol(For Eg a Function Name) is defined in multiple places. In Almost All of the cases the behaviour would a Link Time Error complaining about multiple Symbols exception being Dynamically Linked Frameworks in which case you might see inconsistent behaviour where a Symbol will be loaded from the Dynamic Framework which was first loaded into the memory.

Answer 2

It is simple to determine when a file extension is explicit

• .a - static library
• .dylib - dynamic library

you can use file command

file /some_path/<framework_name>.framework/<framework_name>

//possible results
current ar archive random library //static library
dynamically linked shared library //dynamic library

*It is possible to change it in Build Settings a Mach-O type[About] from Static Library target to Dynamic library as a result .a file will be generated, file command show you dynamically linked shared library but it will be static library

[Vocabulary]
[Static vs dynamic framework]