GETENV(3C) Standard C Library Functions GETENV(3C)

NAME

getenv - return value for environment name

SYNOPSIS

#include <stdlib.h>

char *getenv(const char *name);

DESCRIPTION

The getenv() function searches the environment list (see environ(7)) for
a string of the form name=value and, if the string is present, returns a
pointer to the value in the current environment.

RETURN VALUES

If successful, getenv() returns a pointer to the value in the current
environment; otherwise, it returns a null pointer.

USAGE

The getenv() function can be safely called from a multithreaded
application. Care must be exercised when using both getenv() and
putenv(3C) in a multithreaded application. These functions examine and
modify the environment list, which is shared by all threads in an
application. The system prevents the list from being accessed
simultaneously by two different threads. It does not, however, prevent
two threads from successively accessing the environment list using
getenv() or putenv(3C).

ATTRIBUTES

See attributes(7) for descriptions of the following attributes:


+--------------------+-----------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+--------------------+-----------------+
|Interface Stability | Standard |
+--------------------+-----------------+
|MT-Level | Safe |
+--------------------+-----------------+

SEE ALSO

exec(2), putenv(3C), attributes(7), environ(7), standards(7)

July 24, 2002 GETENV(3C)