korn@datagen.UUCP (05/29/86)
I just received the beta test version of PC/VI Version 1.02 from
Custom Software Systems (For those who don't know it, PC/VI is a
full implementation of VI which runs under MS-DOS). The release
notice which came with the program documented a number of
enhancements and bug fixes, this included a feature called "mode
lines". The release notice stated that this was a feature
implemented in PC/VI just as it is in AT&T's Version 3.9 of UNIX VI.
Now for the big question, what are mode lines?!? Anyone out there
running AT&T VI who can answer this?
John Korn
Data General Corp
{allegra, ihnp4, decvax}!datagen!kornguy@sun.UUCP (06/07/86)
> ...this included a feature called "mode lines". The release notice > stated that this was a feature implemented in PC/VI just as it is in > AT&T's Version 3.9 of UNIX VI. > > Now for the big question, what are mode lines?!? Anyone out there > running AT&T VI who can answer this? "mode lines" are an alleged feature, present not only in the "vi" 3.9 which comes with System V Release 2, but also in the "vi" 3.7 which comes with 4.2BSD. (It's not really "AT&T" "vi", 3.7 comes with S5R1 and is almost identical to the 3.7 that comes with 4.2, and 3.9 is a version that was changed to use "terminfo" and had a few other things done to it.) One of the first or last five lines of the file can be a "mode line". If this line is of the form <stuff>ex:<commands>:<stuff> or <stuff>vi:<commands>:<stuff> OR <stuff>ei:<commands>:<stuff> OR <stuff>vx:<commands>:<stuff> where the <stuff> items represent possibly-null strings and the <commands> is another possibly-null string, it is a "mode line". The <commands> part of the first such line it finds is executed as an "ex" command when the file is read. What's that you say? You have a user named "sex" whose password file entry is at the end of "/etc/passwd", and you get strange error messages when you "vi" the password file? Three guesses why.... 4.3BSD's "vi" has a variable called "modeline", which is off by default; mode line checking is only done if it's on. One hopes this will migrate into S5's "vi". -- Guy Harris {ihnp4, decvax, seismo, decwrl, ...}!sun!guy guy@sun.com (or guy@sun.arpa)