osf1 man page for setreuid

setreuid(2)							System Calls Manual						       setreuid(2)

NAME
       setreuid - Sets real and effective user IDs

SYNOPSIS
       #include <unistd.h> setreuid(	  uid_t ruid,	   uid_t euid );

STANDARDS
       Interfaces documented on this reference page conform to industry standards as follows:

       setreuid:  XPG4-UNIX

       Refer to the standards(5) reference page for more information about industry standards and associated tags.

PARAMETERS
       Specifies the new real user ID.	Specifies the new effective user ID.

DESCRIPTION
       The  setreuid()	function  sets the real and effective user IDs of the current process to the values specified by the ruid and euid parame-
       ters.  If ruid or euid is -1, the corresponding effective or real user ID of the current process is not changed.

       Users may change the effective user ID to the real user ID; only processes with superuser privilege may make other changes.  This  task	is
       normally done by the system's authentication program (for example, login), but is not done for system daemons.

RETURN VALUES
       Upon successful completion, a value of 0 (zero) is returned.  Otherwise, a value of -1 is returned and errno is set to indicate the error.

ERRORS
       The setreuid() function sets errno to the specified values for the following conditions: The value of the ruid or euid parameter is invalid
       or out of range.  The current process is not the superuser and a change other than changing the effective user ID to the real user  ID  was
       specified.

RELATED INFORMATION
       Functions: getuid(2), setgid(2), setregid(2), setruid(3)

       Standards: standards(5) delim off

																       setreuid(2)