Kernel Hacks & Weird Filenames

[Leslie Mikesell]

In article <11204 at mimsy.UUCP> chris at mimsy.UUCP (Chris Torek) writes:
>>In article <11153 at mimsy.UUCP> I wrote:
>>>First, `non-printable characters'.  Well, there are certainly numerous
>
>But it does not.  (`ls' prints `?' for control characters; `ls|cat -v'
>expands them; other programs have other means of displaying them.)

What? How can ls|cat -v display control characters if ls changes them?
Perhaps someone has fixed your utilities and that is the reason this
problem doesn't bother you.  On out-of-the-box SysVr3, if I create
a file named zESC[2J, ls will happily clear a vt100-ish screen before
you can read any of the other filenames.  I added some other ESC sequences
and a few form-feeds and sent the the listing to a couple of different printers
with the expected bizarre results.  A cpio -it listing does likewise (as
it must if the names are to be of any use).  I didn't feel up to dealing
with the problems that imbedding a ctl-S in a name would cause (left as
an exercise for the reader...)

I did know about ls|cat -v (or od -x if you believe that form-feeds are
control characters).  Probably everyone who has used unix more than a day or
two knows about this. My point is that there are more productive things to do.

>
>>It just adds another reason to place some sort of silly user agent
>>between the user and the system.
>There is *always* a user agent (often more than one) between the
>user and the system.  I do not know what you mean here.

Have you ever seen a 3B1?  I mean the sort of thing where the user agent
"knows" when you are typing a filename, generally by associating the
file with the application that uses it. And I call it silly because it
precludes the concept of software tools.