Add a gui command that starts vgi.

* taf-kit/src/cmd_io.cc (gui_command): New command.
* taf-kit/src/getters.cc, taf-kit/src/getters.hh (write_aut): New
function.

ChangeLog

+2012-06-06  Alexandre Duret-Lutz  <adl@lrde.epita.fr>
+
+	Add a gui command that starts vgi.
+
+	* taf-kit/src/cmd_io.cc (gui_command): New command.
+	* taf-kit/src/getters.cc, taf-kit/src/getters.hh (write_aut): New
+	function.
+
 2012-05-22  Alexandre Duret-Lutz  <adl@lrde.epita.fr>
 	* data/vaucanson.xsd: Allow any unknown elements in

taf-kit/src/Makefile.am

 ## Vaucanson, a generic library for finite state machines.
 ## Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2008,
-## 2009, 2010, 2011 The Vaucanson Group.
+## 2009, 2010, 2011, 2012 The Vaucanson Group.
 ##
 ## This program is free software; you can redistribute it and/or
 ## modify it under the terms of the GNU General Public License

taf-kit/src/cmd_io.cc

@@ -2,7 +2,7 @@
 //
 // Vaucanson, a generic library for finite state machines.
 //
-// Copyright (C) 2010, 2011 The Vaucanson Group.
+// Copyright (C) 2010, 2011, 2012 The Vaucanson Group.
 //
 // This program is free software; you can redistribute it and/or
 // modify it under the terms of the GNU General Public License
@@ -17,6 +17,10 @@
 
 #include "commands.hh"
 #include "edition_commands.hh"
+# include <sys/types.h>
+# include <sys/wait.h>
+# include <unistd.h>
+# include <cstdlib>
 
 static int
 data_command(const arguments_t& args)
@@ -43,6 +47,76 @@ display_command(const arguments_t& args)
   return display_aut(get_aut(args, 1), args, 1);
 }
 
+static int
+gui_command(const arguments_t& args)
+{
+  automaton_t a = get_aut(args, 1);
+
+  int filedes[2];
+  if (pipe(filedes))
+    {
+      g_res.stream << "Cannot create pipe." << std::endl;
+      return 1;
+    }
+
+  pid_t child_pid = fork();
+  if (child_pid)
+    {
+      close(filedes[0]);
+      if (child_pid == -1)
+	{
+	  g_res.stream << "Cannot fork." << std::endl;
+	  close(filedes[1]);
+	  return 1;
+	}
+      else
+	{
+	  std::cout.flush();
+	  int old = dup(STDOUT_FILENO);
+	  if (old != -1)
+	    dup2(filedes[1], STDOUT_FILENO);
+	  close(filedes[1]);
+
+	  write_aut(a, std::cout);
+
+	  if (old != -1)
+	    {
+	      dup2(old, STDOUT_FILENO);
+	      close(old);
+	    }
+	  return 0;
+	}
+    }
+  else
+    {
+      close(filedes[1]);
+      dup2(filedes[0], STDIN_FILENO);
+      close(filedes[0]);
+      // execvp will treat its second argument as if it was
+      // "const char* const*".  See the following page for an
+      // explanation of why it is only declared as "char* const*".
+      // http://www.opengroup.org/onlinepubs/000095399/functions/exec.html
+
+      const char* vgijar = getenv("VGIJAR");
+      if (vgijar)
+	{
+	  const char* const argv[] = {"java", "-jar", vgijar, "-", 0};
+	  execvp(argv[0], const_cast<char *const *>(argv));
+	}
+
+      // If running java failed, or ig VGIJAR is not defined, try to
+      // run a command called vgi.
+      const char* const argv[] = {"vgi", "-", 0};
+      execvp(argv[0], const_cast<char *const *>(argv));
+
+      std::cerr << "Failed to execute `" << argv[0] << "'.\n"
+		<< "You should either define an environment variable VGIJAR "
+		<< "that points to the\nlocation of `vgi.jar', or have on your "
+		<< "PATH a script `vgi' that starts VGI." << std::endl;
+      exit(1);
+    }
+}
+
 
 BEGIN_COMMAND_GROUP(io_commands,
 	    "0. Input/Output functions:");
@@ -50,4 +124,6 @@ COMMAND_ENTRY(data, Aut, Text, "Print useful infos about `aut'.");
 COMMAND_ENTRY(cat, Aut, Aut, "Return `aut'.");
 COMMAND_ENTRY(display, Aut, None, "Display `aut'.");
 COMMAND_ENTRY(edit, Aut, None, "Create or edit an automaton interactively.");
+COMMAND_ENTRY(gui, Aut, None,
+	      "launch VGI to create or edit an automaton interactively.");
 END_COMMAND_GROUP

taf-kit/src/getters.cc

@@ -2,7 +2,7 @@
 //
 // Vaucanson, a generic library for finite state machines.
 //
-// Copyright (C) 2006, 2008, 2009, 2010, 2011 The Vaucanson Group.
+// Copyright (C) 2006, 2008, 2009, 2010, 2011, 2012 The Vaucanson Group.
 //
 // This program is free software; you can redistribute it and/or
 // modify it under the terms of the GNU General Public License
@@ -373,6 +373,12 @@ automaton_t get_aut (const arguments_t& args, int n)
   }
 }
 
+int
+write_aut(const automaton_t& aut, std::ostream& out)
+{
+  out << automaton_saver(aut, string_out(), XML());
+  return 0;
+}
 
 int
 write_aut(const automaton_t& aut, const arguments_t& args, int n)

taf-kit/src/getters.hh

@@ -2,7 +2,7 @@
 //
 // Vaucanson, a generic library for finite state machines.
 //
-// Copyright (C) 2006, 2008, 2009, 2010, 2011 The Vaucanson Group.
+// Copyright (C) 2006, 2008, 2009, 2010, 2011, 2012 The Vaucanson Group.
 //
 // This program is free software; you can redistribute it and/or
 // modify it under the terms of the GNU General Public License
@@ -72,6 +72,7 @@ IOAUT_CONTEXT::automaton_t
 get_single_band_aut(const arguments_t& args, int n);
 #endif
 
+int write_aut(const automaton_t& aut, std::ostream& out);
 int write_aut(const automaton_t& aut, const arguments_t& args, int n);
 int display_aut(const automaton_t& aut, const arguments_t& args, int n);