/Users/mourrain/Devel/mmx/basix/src/pipe_port.cpp

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/******************************************************************************
* MODULE     : pipe_port.cpp
* DESCRIPTION: Ports for pipes
* COPYRIGHT  : (C) 2010  Joris van der Hoeven
*******************************************************************************
* This software falls under the GNU general public license and comes WITHOUT
* ANY WARRANTY WHATSOEVER. See the file $TEXMACS_PATH/LICENSE for more details.
* If you don't have this file, write to the Free Software Foundation, Inc.,
* 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
******************************************************************************/

#include <basix/posix_port.hpp>
#include <basix/system.hpp>
#include <string.h>
#include <unistd.h>
#include <signal.h>
#include <sys/wait.h>

#define STDIN 0
#define STDOUT 1
#define STDERR 2
#define IN 0
#define OUT 1
#define TERMCHAR '\1'

extern char **environ;


namespace mmx {

/******************************************************************************
* Pipe ports
******************************************************************************/

class pipe_port_rep: public posix_port_rep {
  string cmd;
  string role;
  nat    pid;

public:
  syntactic expression () const {
    return syn ("pipe_port", syntactic (cmd), syntactic (role));
  }

public:
  inline pipe_port_rep (nat kind, nat fd, nat pid2,
                        const string& cmd2, const string& role2):
    posix_port_rep (kind, fd),
    cmd (cmd2), role (role2), pid (pid2) {}
  inline ~pipe_port_rep () {
    close (this->fd); }
};

port
pipe_port (nat kind, nat fd, nat pid, const string& cmd, const string& role) {
  return (port_rep*) new pipe_port_rep (kind, fd, pid, cmd, role);
}

/******************************************************************************
* Starting a pipe port and public interface
******************************************************************************/

port
pipe_port (const string& cmd) {
  int pp_in [2];  // for data going to the child
  int pp_out[2];  // for data coming from the child
  int pp_err[2];  // for error messages coming from the child

  int e1 = pipe (pp_in ); (void) e1;
  int e2 = pipe (pp_out); (void) e2;
  int e3 = pipe (pp_err); (void) e3;
  int pid= fork ();

  if (pid==0) { // the child
    setsid();
    close (pp_in  [OUT]);
    close (pp_out [IN ]);
    close (pp_err [IN ]);
    dup2  (pp_in  [IN ], STDIN );
    close (pp_in  [IN ]);
    dup2  (pp_out [OUT], STDOUT);
    close (pp_out [OUT]);
    dup2  (pp_err [OUT], STDERR);
    close (pp_err [OUT]);

    system (cmd);
    exit (127);
    // exit (system (cmd) != 0);
  }

  else { // the main process
    int in = pp_in  [OUT];
    close (pp_in [IN]);
    int out= pp_out [IN ];
    close (pp_out [OUT]);
    int err= pp_err [IN ];
    close (pp_err [OUT]);

    port pin = pipe_port (1, in , pid, cmd, "in" );
    port pout= pipe_port (2, out, pid, cmd, "out");
    port perr= pipe_port (2, err, pid, cmd, "err");
    return composite_port (vec<port> (pin, pout, perr),
                           vec<string> ("in", "out", "err"));
  }
}

} // namespace mmx