Re: [Crm114-general] bitten: output <flags> [filename] /output-text/ - output an arbitrary string

[Paolo <oo...@us...>]

On Mon, Dec 18, 2006 at 11:40:47PM -0500, Bill Y wrote:
> 
>     - [x] means *usually* 'take from-' entity 'x'
>     - (x) means *usually* 'write into-' entity 'x'
...
> Yep.  That occurred to me.  But then you end up with the wierdness of 
> the var-restriction syntax washing over into () from []
> (as in, "open file /etc/foo, lseek to byte 10843, and write six bytes")
> 
> How *would* you want to put it?  Note that (stderr 10843 6) is 
> way not supported... it would be a file named "stderr\ 10843\ 6"
> which is probably not what we want.

well, since we already have [:x: seek|skip len] where supported, I see nop
to have also (:x: seek|skip len) where supported. Which means to make 
'seek|skip len' illegal or just ignored for specials stdout|stderr.

> On the other other hand, (x) (y) (z) in SYSCALL means (from) (to) (status),

which is perhaps the grosser violation

>    SYSCALL [var_restriction_string] (:result: :status:) /command/

that sounds +consistent to me: like in MATCH (:z: :x: :y:); keep safe the 
[:src:] (:sink:) rule 1st, then the actual COMMAND rules what you can put 
into [] ().

> which would allow var restrictions in the syscall send, but require
> that you ISOLATEd a temporary if you needed to "build" the string
> out of pieces. 

I don't see the reason|need for that: possible rules for 
?:filename: offset len?:

  where applicable, 
  IF var_restriction_string :: existent var name THEN
    (use it as is OR do recursive expansion) AND perhaps retstart from top
  ELSEIF context doesn't allow for ":filename: offset len" THEN
    use it as it is (plain string)
  ELSEIF there are 2 ' ' AND offset, len expand to int THEN
    likely we have "file|var-name + offset + len"
    try to var-expand file|var-name
    get final string 
    IF such 'final string' is an existent varname THEN
      either
        - it's content is the filename to work on
        - it's content is the string to work on | destination of write to
    ELSE
      use such "final string" as 'filename' for either (filename ... ...) to
      write to or [filename ... ...] to read from.
      In latter case either 
        - complain if there's no such 'filename'
        - use such 'filename' as plain input string, apply offset+len on it
        - just use the whole final string "filename ... ..." as plain input 
          string
  ELSE      
    use the whole "file|var-name offset len" suitably wholly var-expanded
    as [literal input string] or (literal output filename) where makes
    sense. Issue an error only iff the result isn't applicable to the 
    context.

how does it looks like?

-- paolo