How to Use the Command 'lipo' (with Examples)

The lipo command is a versatile tool used to manage Mach-O Universal Binaries on macOS. A Universal Binary is a file format allowing multiple architecture versions of a binary to be contained within a single file. This is particularly useful for software that needs to run natively on different architectures, such as x86_64 and arm64e. The lipo command provides ways to manipulate these binaries— from creating and analyzing to extracting specific architectures.

Use Case 1: Create a Universal File from Two Single-Architecture Files (with Examples)

Code:

lipo path/to/binary_file.x86_64 path/to/binary_file.arm64e -create -output path/to/binary_file

Motivation:
In software development environments that support multiple processor architectures, developers often need to create a single executable that can run on diverse architectures without requiring separate installation packages. This becomes crucial when targeting macOS systems, which may be based on Intel’s x86_64 architecture or Apple’s ARM-based architecture such as arm64e. By creating a Universal Binary, developers streamline distribution and ensure performance optimization on a variety of hardware.

Explanation:

• lipo: This is the command name for the tool.
• path/to/binary_file.x86_64: This specifies the file path to the binary designed for the x86_64 architecture.
• path/to/binary_file.arm64e: This specifies the file path to the binary designed for the arm64e architecture.
• -create: This flag tells lipo to create a new Universal Binary from the input files.
• -output path/to/binary_file: This specifies the output path where the newly created Universal Binary should be saved.

Example Output:
Upon successful execution, there isn’t typically output unless an error occurs. The resulting Universal Binary can be found at the specified output path, ready for deployment across supported architectures.

Use Case 2: List All Architectures Contained in a Universal File (with Examples)

Code:

lipo path/to/binary_file -archs

Motivation:
When working with Universal Binaries, it’s often necessary to understand which architectures an existing binary supports, particularly when diagnosing compatibility or performance issues. Listing all the included architectures helps developers verify the binary’s integrity and ensure all intended architectures are covered.

Explanation:

• lipo: The command name for the tool.
• path/to/binary_file: This specifies the file path to the Universal Binary in question.
• -archs: This flag instructs lipo to list all the architectures that are contained in the provided Universal Binary.

Example Output:

x86_64 arm64e

This output indicates that the Universal Binary contains versions for both the x86_64 and arm64e architectures.

Use Case 3: Display Detailed Information About a Universal File (with Examples)

Code:

lipo path/to/binary_file -detailed_info

Motivation:
Understanding the exact composition of a Universal Binary can be crucial for debugging, auditing, or optimizing software distribution. Detailed information can include sizes of individual architectures within the binary and offsets, offering insights into how resources are allocated and used.

Explanation:

• lipo: The command name for the tool.
• path/to/binary_file: This specifies the path to the Universal Binary.
• -detailed_info: This flag prompts lipo to provide a comprehensive description of the file’s structure, including architecture-specific data.

Example Output:

Architectures in the fat file: path/to/binary_file are: x86_64 arm64e 
Non-fat file: path/to/binary_file is architecture: x86_64 

This output details the architectures included and additional architecture-specific information about the Universal Binary.

Use Case 4: Extract a Single-Architecture File from a Universal File (with Examples)

Code:

lipo path/to/binary_file -thin arm64e -output path/to/binary_file.arm64e

Motivation:
Sometimes, developers need to isolate a particular architecture from a Universal Binary, either for testing purposes or to fulfill specific deployment requirements. Extracting a single architecture allows focused testing or distribution on specific hardware without the overhead of irrelevant binary code.

Explanation:

• lipo: The command name for the tool.
• path/to/binary_file: This indicates the Universal Binary from which to extract a single architecture.
• -thin arm64e: This argument extracts the specified architecture—in this case, arm64e—indicating that only this architecture size should be included in the output.
• -output path/to/binary_file.arm64e: This sets the path for the output file that will contain only the extracted architecture.

Example Output:
The result of this command is the creation of a new file, path/to/binary_file.arm64e, which contains only the arm64e architecture.

Conclusion:

Each use case of the lipo command provides developers with essential tools for managing Universal Binaries, allowing robust, multi-architecture support in macOS development. Whether creating optimized distributables, diagnosing compatibility, or facilitating cross-platform testing, lipo remains an invaluable component in the toolchain for developers working with macOS software projects.