- OS x is a UNIX-like operating system consisting of the underlying Darwin and upper-layer OS X application frameworks (such as cocoa, carbon, and quartz) and the aqua user interface. Darwin is an open-source and complete POSIX-compliant operating system. The kernel is an open-source Mach kernel developed based on CMU, part of the * bsd unix source code and a set of Device Driver frameworks called iokit, a hybrid kernel named xnu and a set of application development interfaces and user interfaces inherited from BSD are constructed.
- Sandbox is a security mechanism that allows applications to run in a relatively isolated environment. Sandbox iN OS X is similar to rule declaration. When compiling a program, developers must declare the file locations and resources that the application needs to access, such as the user's document folder or network access.
- There are three resource libraries. A system resource library is located in/system/library. Unless necessary, users should not modify its content. A local/library is called a shared resource library, which stores globally shared resources. A ~ /Library, called the user resource library, maps the shared resource library to each user.
- Restore partitions: Press and hold the option key at startup.
- System process: the earliest process started in the PID 0 kernel_task system; all non-kernel_task processes of PID 1 launchd execute and start PS: a series of processes are described in detail.
OS X mountain lion book note
