Red Hat Bugzilla – Bug 135406
/bin/vi isn't POSIX compliant
Last modified: 2007-11-30 17:07:04 EST
From Bugzilla Helper: User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.7.2) Gecko/20040908 Description of problem: vim does not enter complete compatibility mode when starting up as "vi", specifically, it does not disable multi-level undo. I expect /bin/vi to be an implementation of vi compliant with POSIX 1003.2, which is quite clear about the behaviour of "u" 5.35.7.1.78 Undo Synopsis: u Reverse the last change made to the current buffer. If repeated, the command shall alternate between these two states, thus is its own inverse. [...] vim will not have this behaviour unless cp is set. Version-Release number of selected component (if applicable): vim-minimal-6.2.98-1 How reproducible: Always Steps to Reproduce: 1. start /bin/vi 2. enter i whatever ESC 3. press u u Actual Results: first whatever disappears, then I get a bell Expected Results: whatever should disappear, then reappear. Additional info:
vim makes no claims to be absolutely POSIX compliant and IMHO multi-level undo is what 99% of our users prefer. There's always the 'redo' comand CTRL-r if want that last changes back. If you insist on POSIX-like undo: Please edit /etc/vimrc or your user .vimrc and a change set nocompatible to set compatible or add that last line if there's no line with set nocompatible.
the bug is not about vim, it is about vi. those who want multi-level undo, can use vim. in a POSIX system, the command PATH=`getconf PATH` vi MUST result in a version of the vi editor which complies with POSIX. this is not the case in Red Hat. now, Red Hat doesn't make any claims of POSIX compliance yet, but it is one of those things which needs to be fixed to be certified. btw, getconf PATH may return something other than /bin as the first element. Solaris does this, it puts some utilities in /usr/xpg4/bin in the cases where changing the behaviour of the utilities in /bin would break too many old scripts. such a change to getconf and a wrapper script /usr/xpg4/bin/vi containing just #! /bin/sh export VIMINIT=":set cp" exec /bin/vi "$@" would be enough to fix the POSIX incompatibility.