[sicsh-develop] Redir and streams

[Ezra P. <epe...@zi...>]

I indicated that I was planning to work on the redir module. (hopefully 
I will have something working before I leave town next week). 

Gary suggested three options for handling output streams:

>    i)  go ahead and add a FILE* stream for now so that you can keep
>        going, and we'll worry about snprintfv later.
>    ii) take a look at snprintfv and install it on your development box,
>        and reference it as an external library for now.
>    iii) take the bull by the horns and add snprintfv in a subdirectory,
>       and make libsic dependent on it.

I have done a hodgepodge for now, based a little on the snprintv idea
and a little craziness - which I will probably have to cleanup.

In the struct sic, I have made a pointer to an opaque structure (similar to the
builtintab) which represent the streams of the particular sic. 

Shis Streams structure will eventually be made up of structures
representing input and output streams. (maybe eventually g_stream in snprintv)
Currently these substructures are a FILE *, a flag indicating if the
stream needs to be closed (we don't want to close stdout). Eventually,
I will probably store a filename and other pertinent information).

I am still working on this, but interfacing to the streams will be
sic_printf(Sic *sic,...), sic_flushout(Sic *sic) and other access
methods as needbe.

I did this to allow me to rip the guts out of the stream handling once
I figure out what is really needed. 

I am still trying to get the basic functionallity working before
getting back to redir. What I am finding is that we might need to
flush stdout before forking in dollar.c and unknown.c - otherwise the
state of stdout is indeterminate - and we get repeats in the output
stream. (this only shows up in non-interactive mode during the tests
because stdout is unbuffered).

When I have an initial version working, I will submit a patch for
review.

	Ezra