freebsd man page for setgroups

SETGROUPS(2)						      BSD System Calls Manual						      SETGROUPS(2)

NAME
     setgroups -- set group access list

LIBRARY
     Standard C Library (libc, -lc)

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

     int
     setgroups(int ngroups, const gid_t *gidset);

DESCRIPTION
     The setgroups() system call sets the group access list of the current user process according to the array gidset.	The ngroups argument indi-
     cates the number of entries in the array and must be no more than {NGROUPS_MAX}+1.

     Only the super-user may set a new group list.

RETURN VALUES
     The setgroups() function returns the value 0 if successful; otherwise the value -1 is returned and the global variable errno is set to indi-
     cate the error.

ERRORS
     The setgroups() system call will fail if:

     [EPERM]		The caller is not the super-user.

     [EINVAL]		The number specified in the ngroups argument is larger than the {NGROUPS_MAX}+1 limit.

     [EFAULT]		The address specified for gidset is outside the process address space.

SEE ALSO
     getgroups(2), initgroups(3)

HISTORY
     The setgroups() system call appeared in 4.2BSD.

BSD
								  April 16, 1994							       BSD