As Apple introduces its new Apple Silicon Macs, it’s important that Mac admins be able to identify if their environment’s software will be able to run natively on both Intel and Apple Silicon as Universal 2 apps or if they’ll need Apple’s Rosetta 2 translation service installed first on their Apple Silicon Macs to allow their apps to run.

To assist with this identification effort, Apple has provided two tools:

• file
• lipo

Both have been around for a while and initially helped identify the original Universal binaries, which were compiled to support both PowerPC and Intel processors. They’ve now been updated for this new processor transition and either will be able to identify if an app’s binary was compiled for the following:

• x86_64 (Intel)
• arm64 (Apple Silicon)
• Both x86_64 and arm64 (Universal 2)

For more details, please see below the jump.

To identify if an app is Intel-only or Universal using the lipo tool, please use the command shown below:

lipo -detailed_info /path/to/binary

For example, on macOS Catalina 10.15.7 Apple’s Safari browser is an Intel-only binary, since macOS Catalina won’t run on an Apple Silicon Mac. Running lipo on macOS Catalina 10.15.7’s Safari should produce output similar to what’s shown below:

username@computername ~ % lipo -detailed_info /Applications/Safari.app/Contents/MacOS/Safari
input file /Applications/Safari.app/Contents/MacOS/Safari is not a fat file
Non-fat file: /Applications/Safari.app/Contents/MacOS/Safari is architecture: x86_64
username@computername ~ %

Likewise, Jamf Pro 10.25.2’s jamf binary now supports both Intel and Apple Silicon. Running the lipo command described above should produce output similar to what’s shown below:

username@computername ~ % lipo -detailed_info /usr/local/jamf/bin/jamf
Fat header in: /usr/local/jamf/bin/jamf
fat_magic 0xcafebabe
nfat_arch 2
architecture x86_64
cputype CPU_TYPE_X86_64
cpusubtype CPU_SUBTYPE_X86_64_ALL
capabilities 0x0
offset 16384
size 6441136
align 2^14 (16384)
architecture arm64
cputype CPU_TYPE_ARM64
cpusubtype CPU_SUBTYPE_ARM64_ALL
capabilities 0x0
offset 6471680
size 6121168
align 2^14 (16384)
username@computername ~ %

To identify if an app is Intel-only or Universal using the file tool, please use the command shown below:

file /path/to/binary

Running the file command described above on macOS Catalina 10.15.7’s Safari should produce output similar to what’s shown below:

username@computername ~ % file /Applications/Safari.app/Contents/MacOS/Safari
/Applications/Safari.app/Contents/MacOS/Safari: Mach-O 64-bit executable x86_64
username@computername ~ %

Running the file command described above on the Jamf Pro 10.25.2 jamf binary should produce output similar to what’s shown below:

username@computername ~ % file /usr/local/jamf/bin/jamf
/usr/local/jamf/bin/jamf: Mach-O universal binary with 2 architectures: [x86_64:Mach-O 64-bit executable x86_64] [arm64]
/usr/local/jamf/bin/jamf (for architecture x86_64):	Mach-O 64-bit executable x86_64
/usr/local/jamf/bin/jamf (for architecture arm64):	Mach-O 64-bit executable arm64
username@computername ~ %

For more information about app testing, Howard Oakley has a blog post discussing the lipo tool in more detail which I recommend checking out. I’ve linked to it below:

Magic, lipo and testing for Universal binaries:
https://eclecticlight.co/2020/07/24/magic-lipo-and-testing-for-universal-binaries/