The getauid() function returns the audit user ID for the current process. This value is initially set at login time and inherited by all child processes. This value does not change when the real/effective user IDs change, so it can be used to identify the logged-in user even when running a setuid program. The audit user ID governs audit decisions for a process.

The setauid() function sets the audit user ID for the current process.

Upon successful completion, the getauid() function returns the audit user ID of the current process on success. Otherwise, it returns -1 and sets errno to indicate the error.

Upon successful completion the setauid() function returns 0. Otherwise, -1 is returned and errno is set to indicate the error.

The getauid() and setauid() functions will fail if:

EFAULT

The auid argument points to an invalid address.

EPERM

The process's effective user ID is not super-user.

Only the super-user may successfully execute these calls.

bsmconv(1M), audit(2), getaudit(2)

The functionality described in this man page is available only if the Basic Security Module (BSM) has been enabled. See bsmconv(1M) for more information.

These system calls have been superseded by getaudit() and setaudit().