Using Environment Variables to Communicate Information About the Current Operating System to Application Programs
Original Publication Date: 2000-Mar-01
Included in the Prior Art Database: 2003-Jun-19
AbstractUsing Environment Variables to Communicate Information About the Current Operating System to Application Programs
Using Environment Variables to Communicate Information About the Current
Operating System to Application Programs
A technique is disclosed for communicating information about the operating system to application programs. This technique assigns operating system information to environment variables. Applications can read the environment variables to obtain the information.
This technique solves a problem found in operating systems where an operating system executable image (a "boot image") is created with a user command, but the boot image is not actually used until the next time that the operating system is restarted. Between the time that a new boot image is created and the operating system is restarted, information about the current boot image is no longer available by reading the boot image from the file system. Using the technique disclosed here, information about the boot image is saved in the boot image itself. When the operating system is restarted, the information about the operating system is loaded along with the rest of the boot image. Since the information is copied into memory, it is not affected if a new boot image is created later.
One setting where this technique would be particularly useful is in an operating system where multiple operating system programs ("kernels") are provided, one of which is selected by the user when the boot image is created. For example, one kernel might provide more debugging capabilities than another. Programs that need to examine operating sys...