how do i read data from a unix command?

[Garry Hodgson]

is there a way i can read the output of a unix command using something
akin to the file:read() functions?  i'd like to open a pipe and get back
a file
that i can do reads from.  something like:

    { ok, FP } = file:open( File, read )
	file:read( FP, ?BUFSIZE )

i know about os:cmd(), but that reads the whole thing at once, 
and the files i'm reading are way too big for that.

thanks

-- 
Garry Hodgson                   One way or another
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Software Innovation Services    One way or another
AT&T Labs                       This darkness got to give...
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