Procedure AssignPipe (Pipe_in ; Pipe_out : Text) ;
Creates a pipe, i.e. two file objects, one for input, one for output. What is written to Pipe_out, can be read from Pipe_in. Reading and writing happens through the usual Readln(Pipe_in,...) and Writeln (Pipe_out,...) procedures.
LinuxError is used to report errors:
POpen,pipe(2)