getenv - get value of environment variable

Definition	#include <stdlib.h> char *getenv(const char *name); getenv() searches the current environment of the process, i.e. the string array pointed to by environ, for a string of the form "name=value" and returns a pointer to the string containing the value for the specified variable name.
Return val.	Value of name
		if a corresponding string exists.
	Null pointer	if no corresponding string exists, or if the S variable SYSPOSIX does not exist.
Notes	The string "name=value" cannot be altered, but may be overwritten by subsequent putenv calls. Other library functions do not overwrite the string. When a program is started, the S variable SYSPOSIX is evaluated as part of the environment definition in addition to the defaults for the environment (see section “Environmentvariables”).
See also	environ, putenv, stdlib.h.