On 4 April 2011 22:35, <smi...@zenzebra.mv.com> wrote:
> roger peppe <rogpe...@gmail.com> writes:
>
>> when i've needed a "-n safe" version of echo in
>> the past, i've used something like this:
>>
>> fn myecho {echo -n $"* ^ '
>> '}
>
> That doesn't work right when (~ $#* 0). It outputs a rogue space prior
> to the newline. echo, with no arguments, should ouput just a newline.
it works fine, with no rogue spaces. did you try it?
> I'm trying to write an Acme client in rc(1). I'd like to avoid spawning
> a new read(1) process every time I make a keystroke or click the mouse.
> Using multi-line reads wouldn't help much, because interactivity needs
> to be maintained.
>
> I'm using rc(1) because the /mnt/acme/%d/events interface is
> well-documented (in /sys/doc/acme/acme.ps), but the C code under
> /acme/bin/source/ for reading /mnt/acme/%d/events it is definitively
> cryptic. I've managed to peel away the extra layers of code from one of
> the simpler Acme clients, in /acme/bin/source/adict/win.c, and am in the
> process of creating a general-purpose Acme event parser in C. The
> output of the filter will be in a form easily digestible by scripts, and
> would provide a good "skeleton" example of event parsing for other
> coders to build upon. (There doesn't currently appear to be any such
> "starter code" under /acme/bin/source or /sys/doc.)
>
> If only Acme put a single extra space immediately prior the first
> integer (c0) in it's event messages, this parsing could have been done
> almost entirely within rc(1).
the usual solution to problems like this is to write a little
helper program in C. you might want to look at
http://man.cat-v.org/p9p/1/acmeevent
