Re: Supplemental groups count in Linux

On 12/8/2024 12:12 AM, vallor wrote:

NGROUPS_MAX is the maximum supplemental group count for a Unix login.
 On Linux, it is 65536.
 But on MacOS and NetBSD, it is 16 -- which is the old standard.
 Even worse, MacOS has all but filled the supplemental groups with
gid's for its own housekeeping:
 $ for II in `id -G -n`; do echo $II ; done
staff
everyone
localaccounts
_appserverusr
admin
_appserveradm
_lpadmin
_appstore
_lpoperator
_developer
_analyticsusers
com.apple.access_ftp
com.apple.access_screensharing
com.apple.access_ssh
com.apple.access_remote_ae
 $ for II in `id -G -n`; do echo $II ; done | wc -l
       15
 What a waste of space!  On Linux:
 $ for II in `id -G -n`; do echo $II ; done
scott
adm
cdrom
sudo
dip
plugdev
lpadmin
sambashare
wireshark
libvirt
nordvpn
 $ for II in `id -G -n`; do echo $II ; done | wc -l
11
 Conclusion:  Linux is a modern OS, with much more administrative
flexibility.  Complex user-sharing configurations can be set
up -- encompassing, if needed, thousands of supplemental
groups.
 p.s. If someone could run this on Windows and report the value,
I'd much appreciate it:
   - - %<- cut here - %<- - -
#include <stdio.h>
#include <limits.h>
 int main (void)
{
 printf("%d\n",NGROUPS_MAX);
 return 0;
}
   - - %<- cut here - %<- - -

D:\temp>tcc ngroups.c -o ngroups.exe
ngroups.c:6: error: 'NGROUPS_MAX' undeclared