SETREUID(2)
NAME
setreuid − set real and effective user IDs
USAGE
setreuid(ruid, euid)
int ruid, euid;
DESCRIPTION
The real and effective user IDs of the current process are set according to the arguments. If ruid or euid is −1, the system fills in the current user ID. Only the super-user may modify the real user ID of a process. Users other than the super-user may only change the effective user ID of a process to the real user ID.
RETURN VALUE
Upon successful completion, a value of zero is returned. Otherwise, a value of −1 is returned, and errno is set to indicate the error.
ERRORS
[EPERM] The current process is not the super-user and a change other than changing the effective user ID to the real user ID was specified.