GETENV(3) Linux Programmer s Manual GETENV(3)

NAME getenv - get an environment variable

SYNOPSIS #include <stdlib.h>

char *getenv(const char *name);

DESCRIPTION The getenv() function searches the environment list to find the envi- ronment variable name, and returns a pointer to the corresponding value string.

RETURN VALUE The getenv() function returns a pointer to the value in the environ- ment, or NULL if there is no match.

CONFORMING TO SVr4, POSIX.1-2001, 4.3BSD, C89, C99.

NOTES The strings in the environment list are of the form name=value.

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).

SEE ALSO clearenv(3), putenv(3), setenv(3), unsetenv(3), environ(7)

COLOPHON This page is part of release 3.22 of the Linux man-pages project. A description of the project, and information about reporting bugs, can be found at

GNU 2008-03-17 GETENV(3)