unsetenv()
QNX SDP8.0C Library ReferenceAPIDeveloper
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:
| Safety: | |
|---|---|
| Cancellation point | No |
| Signal handler | Yes |
| Thread | Yes |
Caveats:
The unsetenv() function manipulates the environment pointed to by the global environ variable.
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