GETENV(3) | Linux Programmer's Manual | GETENV(3) |
NAME
getenv, secure_getenv - get an environment variableSYNOPSIS
#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)):
secure_getenv(): _GNU_SOURCE
DESCRIPTION
The getenv() function searches the environment list to find the environment variable name, and returns a pointer to the corresponding value string.- *
- the process's effective user ID did not match its real user ID or the process's effective group ID did not match its real group ID (typically this is the result of executing a set-user-ID or set-group-ID program);
- *
- the effective capability bit was set on the executable file; or
- *
- the process has a nonempty permitted capability set.
Secure execution may also required if triggered by some Linux security modules.
The secure_getenv() function is intended for use in general-purpose libraries to avoid vulnerabilities that could occur if set-user-ID or set-group-ID programs accidentally trusted the environment.
RETURN VALUE
The getenv() function returns a pointer to the value in the environment, or NULL if there is no match.VERSIONS
secure_getenv() first appeared in glibc 2.17.CONFORMING TO
getenv(): SVr4, POSIX.1-2001, 4.3BSD, C89, C99.NOTES
The strings in the environment list are of the form name=value.SEE ALSO
clearenv(3), getauxval(3), putenv(3), setenv(3), unsetenv(3), capabilities(7), environ(7)COLOPHON
This page is part of release 3.53 of the Linux man-pages project. A description of the project, and information about reporting bugs, can be found at http://www.kernel.org/doc/man-pages/.2012-08-14 | GNU |