X86 Disassembly/Mac OS X

Mach-O format overview
MacOS (Previously OS X) uses the Mach-O file format to encode executables, object files, and shared libraries (.dylib files). Here, we will be looking at the 64-bit version of the Mach-O format. The majority of data in Mach-O files are 'segments' and 'sections', where Segments are containers for Sections, and store information about each Section. The Sections themselves are containers for data. Mach-O files have five primary structures: Note that when each Structure is gone over, they are all an unbroken sequence of bytes, and there is no empty space between them.

Information
The header is the very first thing in the file, and it has 8 unsigned 32-bit integers: