mojave man page for setreuid

SETREUID(2)						      BSD System Calls Manual						       SETREUID(2)

NAME
     setreuid -- set real and effective user IDs

LIBRARY
     Standard C Library (libc, -lc)

SYNOPSIS
     #include <unistd.h>

     int
     setreuid(uid_t ruid, uid_t 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 current uid is filled
     in by the system.	Unprivileged users may change the real user ID to the effective user ID and vice-versa; only the super-user may make other
     changes.

     The setreuid() function has been used to swap the real and effective user IDs in set-user-ID programs to temporarily relinquish the set-user-
     ID value.	This purpose is now better served by the use of the seteuid() function (see setuid(2)).

     When setting the real and effective user IDs to the same value, the standard setuid() function is preferred.

RETURN VALUES
     The setreuid() function returns the value 0 if successful; otherwise the value -1 is returned and the global variable errno is set to indi-
     cate 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.

SEE ALSO
     getuid(2), issetugid(2), seteuid(2), setuid(2)

HISTORY
     The setreuid() system call appeared in 4.2BSD.

BSD
								 February 8, 2001							       BSD