setreuid(2)
NAME
setreuid − set real and effective user ID’s
SYNTAX
setreuid(ruid, euid)
int ruid, euid;
DESCRIPTION
The real and effective user ID’s of the current process are set according to the arguments. If ruid or euid is −1, the current uid is filled in by the system. Only the super-user may modify the real uid of a process. Users other than the super-user may change the effective uid of a process only to the real uid.
Upon successful completion, a value of 0 is returned. Otherwise, a value of −1 is returned and errno is set to indicate the error.
DIAGNOSTICS
[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.