setregid(2) [bsd man page]

SETREGID(2)							System Calls Manual						       SETREGID(2)

NAME

       setregid - set real and effective group ID

SYNOPSIS

       setregid(rgid, egid)
       int rgid, egid;

DESCRIPTION

       The  real and effective group ID's of the current process are set to the arguments.  Unprivileged users may change the real group ID to the
       effective group ID and vice-versa; only the super-user may make other changes.

       Supplying a value of -1 for either the real or effective group ID forces the system to substitute the current ID in place of the -1 parame-
       ter.

RETURN VALUE

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

ERRORS

       [EPERM]	      The  current  process is not the super-user and a change other than changing the effective group-id to the real group-id was
		      specified.

SEE ALSO

       getgid(2), setreuid(2), setgid(3)

4.2 Berkeley Distribution					   May 15, 1985 						       SETREGID(2)

setregid(2)							System Calls Manual						       setregid(2)

Name
       setregid - set real and effective group ID

Syntax
       setregid(rgid, egid)
       int rgid, egid;

Description
       The real and effective group ID's of the current process are set to the arguments.

       Supplying a value of -1 for either the real or effective group ID forces the system to substitute the current ID for the -1 parameter.

Environment
       BSD
       If  the	process is superuser, or and matches with the real group ID, the effective group ID, or the saved set-group-id (as described in ),
       then the real, effective, and saved set-group-id are set to and respectively.

       POSIX
       SYSTEM-FIVE
       When your program is compiled in POSIX or SYSTEM-FIVE mode, the following semantics apply when using the function.

       If the process is the superuser, the real, effective, and saved set-group-id (as described in ) are set to and respectively.

       If the process is not the superuser, but the and matches the real group ID, the effective group ID (only in SYSTEM-FIVE	and  BSD  environ-
       ment), or the saved set-group-id, then the effective ID is set to The real group ID and the saved set-group-id are left unchanged.

Return Values
       Upon successful completion, a value of zero (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 superuser and the and specified does not match with the real group ID or the effective group
		      ID (only in SYSTEM-FIVE and BSD environment) or the saved set-group-id.

See Also
       getgid(2), setreuid(2), setgid(3)

																       setregid(2)