NAME

     setregid — set real and effective group ID

LIBRARY

     Standard C Library (libc, -lc)

SYNOPSIS

     #include <unistd.h>

     int
     setregid(gid_t rgid, gid_t egid);

DESCRIPTION

     The real and effective group ID's of the current process are set to the arguments.  If the
     real group ID is changed, the saved group ID is changed to the new value of the effective
     group ID.

     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 argument.

     The setregid() system call was intended to allow swapping the real and effective group IDs
     in set-group-ID programs to temporarily relinquish the set-group-ID value.  This system call
     did not work correctly, and its purpose is now better served by the use of the setegid(2)
     system call.

     When setting the real and effective group IDs to the same value, the standard setgid()
     system call is preferred.

RETURN VALUES

     The setregid() function returns the value 0 if successful; otherwise the value -1 is
     returned and the global variable 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), issetugid(2), setegid(2), setgid(2), setuid(2)

HISTORY

     The setregid() system call appeared in 4.2BSD.