installnametool

Installnametool is commonly a reference to the macOS command line utility install_name_tool. This tool is part of Apple's development tools and is used to modify the dynamic linking information in Mach-O binaries. It is typically available with the Xcode Command Line Tools and can be found at /usr/bin/install_name_tool. The name is sometimes written without the underscore in informal references, but the official command is install_name_tool.

The primary purpose of install_name_tool is to adjust how a binary finds its dynamic libraries at load time. It can change the install name of a dylib, update references to libraries inside an executable or dylib, and modify runtime search paths used by the dynamic linker (dyld). These operations are essential when bundling applications, relocating libraries, or preparing frameworks for distribution. Changes affect how the runtime linker resolves dependencies without rebuilding the entire project.

Common usage patterns include inspecting a binary with a tool like otool -L to see current dependencies, then applying changes with install_name_tool. Typical operations include:

- Changing a dylib’s install name: install_name_tool -id @executable_path/../Frameworks/MyLib.dylib MyLib.dylib

- Updating a library reference: install_name_tool -change /usr/lib/libOld.dylib @executable_path/../Frameworks/libNew.dylib MyApp

- Modifying runtime search paths: install_name_tool -add_rpath @loader_path/../Frameworks MyApp

Cautions include ensuring the binary is not in use, re-signing if required, and avoiding edits on system-protected binaries under SIP or system integrity protections. Incorrect changes can render a binary unlaunchable.

See also: otool, dyld, Mach-O, codesign.