10 years ago this would have been considered satire
No one is forcing you to change your broken buggy 30-year old shell scripts, you can always continue using them.
How about usernames that start with a digit? Am I still allowed to use those?
* https://ma.ttias.be/giving-perspective-systemds-usernames-st...
Now assuming I have a user called 1000 with UID 2000, and a user called 2000 with UID 1000.
Now what do you think is gonna happen if multiple POSIX-compliant tools call each other?
This is clearly broken, and the reason why BSDs don’t actually implement POSIX cleanly, instead allowing all their tools to take unambiguous identifiers on the CLI, with the # prefix to mark a UID, and have all their tools call all their children with this format.
The POSIX standard is clearly suboptimal here, and the set of valid usernames, and the set of valid UIDs should never have been allowed to overlap.
But how large a proportion of machines do you think have mail delivery rely on .forward or .procmailrc in $HOME these days?
In any case, procmail can be executed directly rather than from .forward in most cases, and can be configured to take the rc file to be a file in /etc/procmail-rcs/ as an alternative to $HOME/.procmailrc (at least the version of procmail in Ubuntu; unlike /etc/procmailrc, the files in /etc/procmail-rcs/ will take on the user id of the user the file is named for, like $HOME/.procmailrc).
User crontabs on my system at least (Ubuntu) are in /var/spool/cron/crontabs/[username], not in $HOME anyway. I can't remember the last system I had with user crontabs in $HOME.
People have had systems where relying on accessing the home directory of a logged out user has been undesirable or impossible for a very long time.
I help run a 500 node HPC cluster that leverages procmail. Do I count?
> User crontabs on my system at least (Ubuntu) are in /var/spool/cron/crontabs/[username], not in $HOME anyway.
The crontab(5) may be there, but where is the script that is actually executed? Probably in $HOME/scripts/ or some such.
> People have had systems where relying on accessing the home directory of a logged out user has been undesirable or impossible for a very long time.
I have daily experiences indicating otherwise. I would hazard to guess that many other syadins in academia & research would agree. Even assuming $HOME is in /home breaks a bunch of stuff:
* https://utcc.utoronto.ca/~cks/space/blog/linux/Ubuntu2004Sna...
