guy@sun.uucp (Guy Harris) (05/25/85)
> An undocumented feature in vi allows a valid command in the file being > 'edited' of the form > > ...ex:{command}: > or > ...vi:{command}: > > to be actioned before interactive editing is allowed. However, the bug > also permits the variants ei and vx. The feature(?) and the bug are in ex/vi 3.7 as well, which comes with 4.2BSD. > The bug was discovered by trying to install a user with the initials 'jei' > into /etc/passwd. The fact that mode-line processing can't be turned off is, arguably, a bug (the same thing may have bitten us here; "vi" acted strangely when editing /etc/passwd, and I think there was an entry that looked like a mode line). Somebody posted some changes to "ex" (which apply both the 4.2BSD's 3.7 and System V Release 2's 3.9) which added a flag "modelines" which, when on, enabled mode-line processing; the default was to disable mode-line processing. Guy Harris
honey@down.FUN (Peter Honeyman) (05/28/85)
the fact that the modelines search is for the pattern [ev][xi]: rather than for (ex|vi): aggravates the problem. peter