unsetenv()

Remove an environment variable

Synopsis:

#include <stdlib.h>

int unsetenv( const char* name );

Arguments:

name: The name of the environment variable that you want to delete.

Library:

libc

Use the -l c option to qcc to link against this library. This library is usually included automatically.

Description:

The unsetenv() function removes the environment variable named name from the process's environment. If the named variable doesn't exist, unsetenv() indicates success and doesn't change the environment.

Returns:

0: Success.
-1: An error occurred; errno is set, and the environment isn't changed.

Errors:

EINVAL: The name argument is NULL, points to an empty string, or points to a string containing an equals (=) character.

Classification:

POSIX 1003.1

Safety:
Cancellation point	No
Interrupt handler	No
Signal handler	Yes
Thread	Yes

Caveats:

The unsetenv() function manipulates the environment pointed to by the global environ variable.