thnx davorg

that works great!!.
I only don't understand how I should use the *Reader and *Writer together with 'use warnings' and 'use strict'.
For now (without strict and warnings) I have 
#! /usr/bin/perl
use FileHandle;
use IPC::Open2;

$pid = open2(*Reader, *Writer, "./progX" );
print Writer "X\n\n1\n2\n\n\n" ;

{ local $/ ;
  $inp = <Reader> ;
}
# or @inp = <Reader>
close Writer, Reader ;

print "Reader: $inp\n" ;

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In reply to Re: need to read/write from/to an external program by jeanluca
in thread need to read/write from/to an external program by jeanluca

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