LEX Question

[Dave Jones]

> In article <32240 at auc.UUCP> tab at auc.UUCP (0-Terrence Brannon ) writes:
>>My question is, is there anyway that I could have the lex program accept
>>integers from somewhere other that stdin? ...
> 

The officially sanctioned way is to redefine the macros
input(), and unput(). But if you want to do a quick and dirty,
probably unportable hack, read on.

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Now then, the following is probably true for all BSD derived
Unixes, and maybe for others, I dunno.

I don't know if it's documented, but you can assign another
FILE* to the variable [yyin]. Then the standard input() and unput()
will work on that stream instead of stdin.

If you want the input to come from something other than a file
descriptor, as you seemed to imply, you can try being even more
devious:  Munge around with the struct _iobuf, perhaps using _IOMYBUF
and _IOSTRG flags. (If you have the source to sscanf() take a look
at that. It uses the same trick.)  I have not tried this, so if it 
doesn't work, well that's life.  You will have to be sure that the 
buffer is never depleted, less _filbuf get called.

And remember, if anyone asks, _I_ never told you to do it that way!