SystemCall on Windows now uses ShellExecute for python scripts

Common/GmshMessage.cpp

@@ -124,12 +124,15 @@ void Msg::Init(int argc, char **argv)
     char *tmp = getenv("PYTHONPATH");
     if(tmp){
       path = tmp;
+#if defined(WIN32)
+      path += ";" + split[0];
+#else
       path += ":" + split[0];
+#endif
     }
     else
       path = split[0];
-    setenv("PYTHONPATH", path.c_str(), 1);
-    printf("pythonpath = %s\n", path.c_str());
+    SetEnvironmentVar("PYTHONPATH", path.c_str());
   }
 
   InitializeOnelab("Gmsh");

Common/OS.cpp

@@ -53,6 +53,15 @@ const char *GetEnvironmentVar(const char *var)
 #endif
 }
 
+const void SetEnvironmentVar(const char *var, const char *val)
+{
+#if !defined(WIN32)
+  setenv(var, val, 1);
+#else
+  _putenv((std::string(var) + "=" + std::string(val)).c_str());
+#endif
+}
+
 double GetTimeInSeconds()
 {
 #if !defined(WIN32) || defined(__CYGWIN__)
@@ -197,6 +206,25 @@ int KillProcess(int pid)
 int SystemCall(const std::string &command, bool blocking)
 {
 #if defined(WIN32)
+  // check if we are trying to execute a Python script
+  std::string exe, args;
+  std::string::size_type pos = command.find_first_of(" ");
+  if(pos != std::string::npos){
+    exe = command.substr(0, pos);
+    args = command.substr(pos, command.size() - pos);
+  }
+  else exe = command;
+  int s = exe.size();
+  if(s > 3 && 
+     (exe[s-3] == '.') &&
+     (exe[s-2] == 'p' || exe[s-2] == 'P') &&
+     (exe[s-1] == 'y' || exe[s-1] == 'Y')){
+    Msg::Info("Shell opening '%s' with arguments '%s'", 
+	      exe.c_str(), args.c_str());
+    ShellExecute(NULL, (char*)"open", (char*)exe.c_str(), 
+		 (char*)args.c_str(), NULL, 0);
+  }
+  else{
     STARTUPINFO suInfo;
     PROCESS_INFORMATION prInfo;
     memset(&suInfo, 0, sizeof(suInfo));
@@ -219,6 +247,7 @@ int SystemCall(const std::string &command, bool blocking)
 		    NORMAL_PRIORITY_CLASS|DETACHED_PROCESS, NULL, NULL,
 		    &suInfo, &prInfo);
     }
+  }
   return 0;
 #else
   if(!system(NULL)) {

Common/OS.h

@@ -9,6 +9,7 @@
 #include <string>
 
 const char *GetEnvironmentVar(const char *var);
+void SetEnvironmentVar(const char *var, const char *val);
 double GetTimeInSeconds();
 void SleepInSeconds(double s);
 void CheckResources();