From mboxrd@z Thu Jan 1 00:00:00 1970 From: dave@horsfall.org (Dave Horsfall) Date: Sat, 28 Apr 2018 02:26:16 +1000 (EST) Subject: [TUHS] rm command In-Reply-To: <20180425221716.B4C6718C086@mercury.lcs.mit.edu> References: <20180425221716.B4C6718C086@mercury.lcs.mit.edu> Message-ID: On Wed, 25 Apr 2018, Noel Chiappa wrote: > On early PDP-11 Unixes, 'rm' is an ordinary program, and 'rmdir' is > setuid-root, since it has to do special magic (writing into directory > files, etc). Given that, it made sense to have 'rm' run with the least > amount of privilege needed to do its job. I am constantly bemused by the number of "setuid root" commands, when a simple "setgid whatever" will achieve the same task. My mantra has always been: "If you think you need setuid root, then you are probably thinking wrong." My favourite here is the "ps" command: On my FreeBSD server: % ls -l /bin/ps -r-xr-xr-x 1 root wheel 35640 Oct 15 2017 /bin/ps On my crappy MacBook: % ls -l /bin/ps -rwsr-xr-x 1 root wheel 51200 Jul 15 2017 /bin/ps (I didn't check my Penguin box, because I don't think that I'll like what I'll see.) -- Dave