vi '_' command

[merlyn at sequent.UUCP]

/--\
| o |
|   <   . . . . . ... food for the line gobbler
\--/


Dave Decot, of Nowhere, USA, writes:

        What does the undocumented vi 3.7 command '_' (underline)  mean?
        What  are its implications?  It seems to be a synonym for 0 or ^
        or something, but I haven't figured out why you would want it.

        And what is the :ab command?  Seems to allow abbreviations,  but
        I  don't  have  any  documentation  on  it.  Nobody answered Jim
        Davis's question about the ~ (capitalize one character) command,
        either.  My manual says both of these characters are "Unused."

Well, Dave, here's your answer, because You Asked For It!

        The "_" (underline) command means "line", like "w"  means  word,
        and  "G"  means  end-of-file (kinda).  It exists in most, if not
        all, versions of vi.  Its presence isn't document, because using
        it is just like doubling the verb!  That means, "dd" is the same
        as "d_", "yy" is the same as "y_", and so on.  The  comments  in
        the  source  read  to  something  like  "this command was phased
        out... stuttering on a key seems like a  more  natural  action".
        You're  right  in  asking  "why  you would wan't it", because it
        isn't really needed... it's just there for backward compatibili-
        ty.

        Now, for the other things you mentioned, they are  all  document
        quite  nicely in the Berkeley paper entitled "Ex changes -- Ver-
        sion 3.1 to 3.5".  True, true, this isn't the original spec, but
        then  again,  the  original  spec says that it documents Version
        3.1!  [Hmm, I just noticed that my version is  3.7...  I  wonder
        what else they've added!]


And that, Dave, is your answer, because You Asked For It!

For asking this week's question, Dave wins a $10 bit-twiddler...
guaranteed to change bits right before your eyes.  [Editors note:
we can't send it to Dave, since he has no address.]

Randal L. Schwartz, esq.
Sequent Computer Systems, Inc.
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