#include <stdlib.h> char *getenv(const char *name); char *secure_getenv(const char *name);
Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
The GNU-specific secure_getenv() function is just like getenv() except that it returns NULL in cases where "secure execution" is required. Secure execution is required if one of the following conditions was true when the program run by the calling process was loaded:
Secure execution may also required if triggered by some Linux security modules.
|getenv(), secure_getenv()||Thread safety||MT-Safe env|
As typically implemented, getenv() returns a pointer to a string within the environment list. The caller must take care not to modify this string, since that would change the environment of the process.
The implementation of getenv() is not required to be reentrant. The string pointed to by the return value of getenv() may be statically allocated, and can be modified by a subsequent call to getenv(), putenv(3), setenv(3), or unsetenv(3).