|  |  4.9.6 Pipe links Pipe links provide access to stdin and stdout of any program.
Pipe links are bidirectional.
Syntax:"|: "+ string_for_system
The string_for system will be passed to systemafter conneting
the input and output to the corresponding stdout and stdin. 
Example:
 |  |   link l="|: date";
  open(l); l;
==> // type : pipe
==> // mode : 
==> // name : date
==> // open : yes
==> // read : not ready
==> // write: ready
  read(l);
==> Fr 15. Mai 14:28:28  2020
  l;
==> // type : pipe
==> // mode : 
==> // name : date
==> // open : yes
==> // read : not ready
==> // write: ready
  close(l);
 | 
 
 |