Laurent Bercot:
[...] direct adaptations from daemontools' setuidgid and envuidgid [...]
There is a similar history, and a similar spread of tools in the nosh toolset for roughly the same reasons. There was a need for a split toolset where one could look up things in the system account database, do stuff (in particular stuff that obscured access to the system account database), and then later change the process user/group IDs. There was also a need for tools that did not manipulate the user ID but only the group IDs. Hence envgid, envuidgid, getuidgid, setgid-fromenv, and setuidgid-fromenv; with setuidgid effectively being envuidgid followed by setuidgid-fromenv (except that it does not touch the environment).
Uwe Ohse did the first setuidgid-fromenv tool, I believe, as a patch to daemontools back in 2001. Several people have developed tools in this way.
* http://jdebp.uk./Softwares/nosh/guide/commands/setuidgid.xml * http://jdebp.uk./Softwares/nosh/guide/commands/envuidgid.xml * https://ohse.de/uwe/patches.html
