Added a way to get the exit code from InputPipe

The method is to call wait() on the pipe object
which returns the exit code.

Some tests have been added for this.

src/tl/tl/tlStream.cc

@@ -966,11 +966,17 @@ InputPipe::~InputPipe ()
 void
 InputPipe::close ()
 {
+  wait ();
+}
+
+int InputPipe::wait ()
+{
+  int ret = 0;
   if (m_file != NULL) {
-    pclose (m_file);
-    //  TODO: pclose delivers the exit code - we should indicate it as return value of close.
+    ret = pclose (m_file);
     m_file = NULL;
   }
+  return ret;
 }
 
 size_t 

src/tl/tl/tlStream.h

@@ -326,6 +326,7 @@ public:
 
   /**
    *  @brief Closes the pipe
+   *  This method will wait for the child process to terminate.
    */
   virtual void close ();
 
@@ -352,6 +353,11 @@ public:
     return std::string ();
   }
 
+  /**
+   *  @brief Closes the pipe and returns the exit code of the child process
+   */
+  int wait ();
+
 private:
   //  No copying
   InputPipe (const InputPipe &);

src/tl/unit_tests/tlStreamTests.cc

@@ -0,0 +1,44 @@
+
+/*
+
+  KLayout Layout Viewer
+  Copyright (C) 2006-2018 Matthias Koefferlein
+
+  This program is free software; you can redistribute it and/or modify
+  it under the terms of the GNU General Public License as published by
+  the Free Software Foundation; either version 2 of the License, or
+  (at your option) any later version.
+
+  This program is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with this program; if not, write to the Free Software
+  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+
+*/
+
+#include "tlStream.h"
+#include "tlUnitTest.h"
+
+TEST(InputPipe1)
+{
+  tl::InputPipe pipe ("echo HELLOWORLD");
+  tl::InputStream str (pipe);
+  tl::TextInputStream tstr (str);
+  EXPECT_EQ (tstr.get_line (), "HELLOWORLD");
+  EXPECT_EQ (pipe.wait (), 0);
+}
+
+TEST(InputPipe2)
+{
+  tl::InputPipe pipe ("thiscommanddoesnotexistithink 2>&1");
+  tl::InputStream str (pipe);
+  tl::TextInputStream tstr (str);
+  tstr.get_line ();
+  int ret = pipe.wait ();
+  tl::info << "Process exit code: " << ret;
+  EXPECT_NE (ret, 0);
+}