View and modify the Mac version number

1. view the Mac version:
First open the terminal application-> utility-> Terminal
Run the following command: More/system/library/coreservices/systemversion. plist
<? XML version = "1.0" encoding = "UTF-8"?>
<! Doctype plist public "-// Apple // DTD plist 1.0 // en" http://www.apple.com/DTDs/
PropertyList-1.0.dtd>
<Plist version = "1.0">
<Dict>
<Key> productbuildversion </key>
<String> 9f33 </string>
<Key> productcopyright </key>
<String> 1983-2008 Apple Inc. </string>
<Key> productname </key>
<String> Mac OS X </string>
<Key> productuservisibleversion </key>
<String> 10.6.7</String>
<Key> productversion </key>
<String> 10.6.7</String>
</Dict>
</Plist>
10.6.7 is the version number.

2. Modify the version number
During the installation of some software (xcode), the system will prompt that the version is low and must be upgraded to a later version. Many people do not want to upgrade the software but need to install it, in this case, you only need to change the version number to the version number required for software installation.
Because systemversion. plist is a system read-only file, the current user cannot change this file to a writable type and needs to switch to the administrator user.
Enter the terminal (as shown above), enter the Sudo-s and password, change the/system/library/coreservices/systemversion. plist file to writable, and then change the version number to the required minimum version.

A. Choose Terminal application> utility> terminal.
B. Switch to the Administrator Sudo-s and press enter to enter the password.
C. Modify systemversion. plist to writable.
Chmod + x/system/library/coreservices/systemversion. plist
D. Use VI to edit files
VI/system/library/coreservices/systemversion. plist
E. Press "a" to edit and modify the version number.
F. After saving and exiting the modification, Press ESC and enter WQ (if you do not know, search for the Linux VI command ).

The software can be successfully installed.