The ANSI function getenv() returns the value of an environment variable. getenv() takes a C-string containing an environment variable and returns its value. In the following example, getenv() detects the value of the environment variable PATH:
char * curr_path = getenv("PATH");
A typical output string of this program may look like this:
Using getenev() instead of a platform specific API has two advantages: your code is portable because getenv() is a standard functions, and the application doesn't need to link to MFC or Win API runtime libraries and dll's that have adverse effects on a program's speed and size.