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setuid(2)			 System	Calls			     setuid(2)

NAME
       setuid, setegid,	seteuid, setgid	- set user and group IDs

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

       int setuid(uid_t	uid);

       int setgid(gid_t	gid);

       int seteuid(uid_t euid);

       int setegid(gid_t egid);

DESCRIPTION
       The  setuid()  function	sets  the real user ID,	effective user ID, and
       saved user ID of	the calling process. The setgid()  function  sets  the
       real  group  ID,	 effective group ID, and saved group ID	of the calling
       process.	The setegid() and seteuid() functions set the effective	 group
       and  user  IDs  respectively  for the calling process. See intro(2) for
       more information	on real, effective, and	saved user and group IDs.

       At login	time, the real user ID,	effective user ID, and saved  user  ID
       of  the	login  process are set to the login ID of the user responsible
       for the creation	of the process.	The same is true for the real,	effec-
       tive, and saved group IDs; they are set to the group ID of the user re-
       sponsible for the creation of the process.

       When a process calls one	of the exec(2) family of functions to  execute
       a file (program), the user and/or group identifiers associated with the
       process can change. If the file executed	is a set-user-ID file, the ef-
       fective	and  saved user	IDs of the process are set to the owner	of the
       file executed. If the file executed is a	set-group-ID file, the	effec-
       tive  and  saved	 group	IDs of the process are set to the group	of the
       file executed. If the file executed is not a set-user-ID	or  set-group-
       ID  file, the effective user ID,	saved user ID, effective group ID, and
       saved group ID are not changed.

       If the {PRIV_PROC_SETID}	privilege is asserted in the effective set  of
       the  process  calling setuid(), the real, effective, and	saved user IDs
       are set to the uid argument.  If	the uid	argument is 0 and none of  the
       saved,  effective  or real UID is 0, additional restrictions apply. See
       privileges(5).

       If the {PRIV_PROC_SETID}	privilege is not  asserted  in	the  effective
       set,  but  uid  is  either the real user	ID or the saved	user ID	of the
       calling process,	the effective user ID is set to	uid.

       If the {PRIV_PROC_SETID}	privilege is asserted in the effective set  of
       the  process calling setgid(), the real,	effective, and saved group IDs
       are set to the gid argument.

       If the {PRIV_PROC_SETID}	privilege is not  asserted  in	the  effective
       set,  but  gid is either	the real group ID or the saved group ID	of the
       calling process,	the effective group ID is set to gid.

RETURN VALUES
       Upon successful completion, 0 is	returned. Otherwise,  -1  is  returned
       and errno is set	to indicate the	error.

ERRORS
       The setuid() and	setgid() functions will	fail if:

       EINVAL	       The value of uid	or gid is out of range.

       EPERM	       For setuid() and	seteuid(), the {PRIV_PROC_SETID} priv-
		       ilege is	not asserted in	the effective set of the call-
		       ing  process and	the uid	argument does not match	either
		       the real	or saved user IDs, or an attempt  is  made  to
		       change  to UID 0	and none of the	existing UIDs is 0, in
		       which case additional privileges	are required.

		       For setgid() and	setegid(), the {PRIV_PROC_SETID} priv-
		       ilege  is not asserted in the effective set and the gid
		       argument	does not match either the real or saved	 group
		       IDs.

ATTRIBUTES
       See attributes(5) for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE	TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |Interface Stability	     |Standard			   |
       +-----------------------------+-----------------------------+
       |MT-Level		     |Async-Signal-Safe		   |
       +-----------------------------+-----------------------------+

SEE ALSO
       intro(2),   exec(2),   getgroups(2),   getuid(2),   stat.h(3HEAD),  at-
       tributes(5), privileges(5), standards(5)

SunOS 5.10			  20 Jan 2003			     setuid(2)

NAME | SYNOPSIS | DESCRIPTION | RETURN VALUES | ERRORS | ATTRIBUTES | SEE ALSO

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