objective c - iOS is it a static or a dynamic framework?

Question

This might sound like a silly question but If you have a thirdParty.framework file, can you tell if it's static or dynamic? I mean, do they look different if you look inside?

Answer 1

It can be either.

Only iOS8+ will allow dynamic frameworks in the app bundle, however.

The way to find out is to look in the .framework and use the file command on the main file:

$ cd iOS/Crashlytics.framework
$ ls -l
total 9984
-rwxr-xr-x  1 andy  staff  4710656 11 Sep 17:11 Crashlytics
drwxr-xr-x  8 andy  staff      272 11 Sep 17:11 Headers
-rw-r--r--  1 andy  staff     1553 11 Sep 17:11 Info.plist
drwxr-xr-x  3 andy  staff      102 11 Sep 17:11 Modules
-rwxr-xr-x  1 andy  staff   146164 11 Sep 17:11 run
-rwxr-xr-x  1 andy  staff   241688 11 Sep 17:11 submit
$ file Crashlytics 
Crashlytics: Mach-O universal binary with 5 architectures
Crashlytics (for architecture armv7):   current ar archive random library
Crashlytics (for architecture armv7s):  current ar archive random library
Crashlytics (for architecture i386):    current ar archive random library
Crashlytics (for architecture x86_64):  current ar archive random library
Crashlytics (for architecture arm64):   current ar archive random library

Where ar archive means "static library".

Alternatively, a "dynamic" framework will look like this and explicitly state that it's dynamically linked.

$ cd /Library/Frameworks/iTunesLibrary.framework/
$ ls -l
total 40
lrwxr-xr-x  1 root  wheel   24 10 Sep 17:38 Headers -> Versions/Current/Headers
lrwxr-xr-x  1 root  wheel   24 10 Sep 17:38 Modules -> Versions/Current/Modules
lrwxr-xr-x  1 root  wheel   26 10 Sep 17:38 Resources -> Versions/Current/Resources
drwxr-xr-x  4 root  wheel  136 10 Sep 17:41 Versions
lrwxr-xr-x  1 root  wheel   22 10 Sep 17:38 XPCServices -> Versions/A/XPCServices
lrwxr-xr-x  1 root  wheel   30 10 Sep 17:38 iTunesLibrary -> Versions/Current/iTunesLibrary
$ file Versions/Current/iTunesLibrary 
Versions/Current/iTunesLibrary: Mach-O universal binary with 2 architectures
Versions/Current/iTunesLibrary (for architecture i386): Mach-O dynamically linked shared library i386
Versions/Current/iTunesLibrary (for architecture x86_64):   Mach-O 64-bit dynamically linked shared library x86_64