Implement process I/O helper.

src/util-io.scm

@@ -30,6 +30,7 @@
  (
   read-lines/no-bom
   get-process-output-lines
+  process-send/recv
   )
 
  (import scheme
@@ -64,4 +65,17 @@
        (let-values (((a b c) (process-wait pid)))
 	 result))))
 
+ ;; Invokes given command with given arguments, gives it all input
+ ;; lines and returns the output lines.
+ (define (process-send/recv cmd args . lines)
+   (let-values (((stdout stdin pid stderr) (process* cmd args)))
+     (let loop ((lines lines))
+       (when (not (null? lines))
+	 (display (car lines) stdin)
+	 (newline stdin)
+	 (loop (cdr lines))))
+     (let ((result (read-lines stdout)))
+       (let-values (((pid exit-ok? exit/signal) (process-wait pid)))
+	 result))))
+
  )