unsetenv

Synopsis

#include <stdlib.h>

int unsetenv(const char *name);

Status

Partially implemented

Conformance

IEEE Std 1003.1-2017

Description

The unsetenv() function shall remove an environment variable from the environment of the calling process. The name argument points to a string, which is the name of the variable to be removed. The named argument shall not contain a '=' character. If the named variable does not exist in the current environment, the environment shall be unchanged and the function is considered to have completed successfully.

The unsetenv() function shall update the list of pointers to which environ points.

Return value

Upon successful completion, zero shall be returned. Otherwise, -1 shall be returned, errno set to indicate the error, and the environment shall be unchanged.

Errors

The function shall fail if:

• EINVAL - The name argument points to an empty string, or points to a string containing a '=' character.

Tests

Tested

Known bugs

None

See Also

1. Standard library functions

2. Table of Contents