setresuid(2) [freebsd man page]

SETRESUID(2)						      BSD System Calls Manual						      SETRESUID(2)

NAME

     getresgid, getresuid, setresgid, setresuid -- get or set real, effective and saved user or group ID

LIBRARY

     Standard C Library (libc, -lc)

SYNOPSIS

     #include <sys/types.h>
     #include <unistd.h>

     int
     getresgid(gid_t *rgid, gid_t *egid, gid_t *sgid);

     int
     getresuid(uid_t *ruid, uid_t *euid, uid_t *suid);

     int
     setresgid(gid_t rgid, gid_t egid, gid_t sgid);

     int
     setresuid(uid_t ruid, uid_t euid, uid_t suid);

DESCRIPTION

     The setresuid() system call sets the real, effective and saved user IDs of the current process.  The analogous setresgid() sets the real,
     effective and saved group IDs.

     Privileged processes may set these IDs to arbitrary values.  Unprivileged processes are restricted in that each of the new IDs must match one
     of the current IDs.

     Passing -1 as an argument causes the corresponding value to remain unchanged.

     The getresgid() and getresuid() calls retrieve the real, effective, and saved group and user IDs of the current process, respectively.

RETURN VALUES

     Upon successful completion, the value 0 is returned; otherwise the value -1 is returned and the global variable errno is set to indicate the
     error.

ERRORS

     [EPERM]		The calling process was not privileged and tried to change one or more IDs to a value which was not the current real ID,
			the current effective ID nor the current saved ID.

     [EFAULT]		An address passed to getresgid() or getresuid() was invalid.

SEE ALSO

     getegid(2), geteuid(2), getgid(2), getuid(2), issetugid(2), setgid(2), setregid(2), setreuid(2), setuid(2)

HISTORY

     These functions first appeared in HP-UX.

BSD
								 February 7, 2015							       BSD

setresuid(2)							System Calls Manual						      setresuid(2)

NAME

       setresuid, setresgid - set real, effective, and saved user and group IDs

SYNOPSIS

DESCRIPTION

       sets the real, effective and/or saved user ID of the calling process.

       If  the	current  real,	effective  or saved user ID is equal to that of a user having appropriate privileges, sets the real, effective and
       saved user IDs to ruid, euid, and suid, respectively.  Otherwise, only sets the real, effective, and saved user IDs if ruid, euid, and suid
       each match at least one of the current real, effective, or saved user IDs.

       If ruid, euid, or suid is leaves the current real, effective or saved user ID unchanged.

       sets the real, effective and/or saved group ID of the calling process.

       If  the	current  real,	effective or saved user ID is equal to that of a user having appropriate privileges, sets the real, effective, and
       saved group ID to rgid, egid, and sgid, respectively.  Otherwise, only sets the real, effective and saved group ID if rgid, egid, and  sgid
       each match at least one of the current real, effective or saved group ID.

       If rgid, egid, or sgid is leaves the current real, effective or saved group ID unchanged.

   Security Restrictions
       Some  or  all  of  the actions associated with this system call require the privilege (CHSUBJIDENT).  Processes owned by the superuser will
       have this privilege.  Processes owned by other users may have this privilege, depending on system configuration.

       See privileges(5) for more information about privileged access on systems that support fine-grained privileges.

RETURN VALUE

       Upon successful completion, and return 0; otherwise, they return -1 and set to indicate the error.

ERRORS

       and fail if any of the following conditions are encountered:

	      ruid,	     euid, or suid (rgid, egid, or sgid) is not a valid user (group) ID.

	      None of the conditions above are met.

AUTHOR

       and were developed by HP.

SEE ALSO

       exec(2), getuid(2), setuid(2), privileges(5).

																      setresuid(2)