Redirect standard input and output of R

I'm trying to write a C program that write to the standard input of R
and read the standard output. I can perfectly read the R output, but
I'm not able of writing anything to R.
[SNIP C code]

Several years ago, I wrote some software that used S-plus as its
back-end and Java for the front-end. I found what worked best was
to add a pseudoterminal inbetween; you can use the code from
"UNIX Programming Environment" to create one. The solution was
later reused when a similar project used R for its back-end.

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SIGSIG -- signature too long (core dumped)