Merge branch 'fix-systemcall' into 'develop'

replace system() call with vfork/exec combination (issue #185)

Tested systemCall function object, dynamicCode, but should be rechecked with IB+openmpi
@Prashant

See merge request !55

applications/test/cstring/Make/files

@@ -0,0 +1,3 @@
+Test-cstring.C
+
+EXE = $(FOAM_USER_APPBIN)/Test-cstring

applications/test/cstring/Make/options

@@ -0,0 +1,2 @@
+/* EXE_INC = -I$(LIB_SRC)/cfdTools/include */
+/* EXE_LIBS = -lfiniteVolume */

applications/test/cstring/Test-cstring.C

@@ -0,0 +1,99 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | Copyright (C) 2016 OpenCFD Ltd.
+     \\/     M anipulation  |
+-------------------------------------------------------------------------------
+License
+    This file is part of OpenFOAM.
+
+    OpenFOAM 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 3 of the License, or
+    (at your option) any later version.
+
+    OpenFOAM 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 OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
+
+Description
+    Test some string functionality
+
+\*---------------------------------------------------------------------------*/
+
+#include "CStringList.H"
+#include "DynamicList.H"
+#include "IOstreams.H"
+#include "fileNameList.H"
+#include "stringList.H"
+#include "wordList.H"
+
+using namespace Foam;
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+int print(int argc, char *argv[])
+{
+    Info<< "argc=" << argc << endl;
+    for (int i=0; i<argc; ++i)
+    {
+        Info<< "  argv[" << i << "] = \"" << argv[i] << "\"" << endl;
+    }
+    return argc;
+}
+
+int print(const CStringList& cstrLst)
+{
+    return print(cstrLst.size(), cstrLst.strings());
+}
+
+
+// Main program:
+
+int main(int argc, char *argv[])
+{
+    DynamicList<string> dynlst;
+    dynlst.reserve(16);
+
+    dynlst.append("string1 with content");
+    dynlst.append("string2 other content");
+    dynlst.append("string3 done");
+
+    {
+        CStringList inC(dynlst);
+
+        Info<< "input: " << dynlst << endl;
+        print(inC);
+    }
+
+    Info<<"command-line with " << CStringList::count(argv) << " items"<< endl;
+
+    print(argc, argv);
+    {
+        dynlst.clear();
+        for (int i=0; i<argc; ++i)
+        {
+            dynlst.append(argv[i]);
+        }
+
+        Info<< "input: " << dynlst << endl;
+        CStringList inC(dynlst);
+        inC.reset(dynlst);
+
+        print(inC);
+        Info<< "length: " << inC.length() << endl;
+        std::cout.write(inC.data(), inC.length());
+    }
+
+
+    Info<< "\nEnd\n" << endl;
+    return 0;
+}
+
+
+// ************************************************************************* //

applications/utilities/miscellaneous/foamHelp/helpTypes/helpType/helpType.C

@@ -151,7 +151,7 @@ void Foam::helpType::displayDoc
         Info<< "Source file: " << classDirectory.c_str() << classFile << nl
             << endl;
 
-        system(docBrowser);
+        Foam::system(docBrowser);
     }
     else
     {

applications/utilities/postProcessing/dataConversion/foamToVTK/foamToVTK.C

@@ -1309,7 +1309,7 @@ int main(int argc, char *argv[])
                       + "_"
                       + procFile.name()
                     );
-                    if (system(cmd.c_str()) == -1)
+                    if (Foam::system(cmd.c_str()) == -1)
                     {
                         WarningInFunction
                             << "Could not execute command " << cmd << endl;

applications/utilities/preProcessing/viewFactorsGen/viewFactorsGen.C

@@ -3,7 +3,7 @@
   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
    \\    /   O peration     |
     \\  /    A nd           | Copyright (C) 2011-2016 OpenFOAM Foundation
-     \\/     M anipulation  |
+     \\/     M anipulation  | Copyright (C) 2016 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -191,9 +191,15 @@ void writeRays
             str << "l " << vertI-1 << ' ' << vertI << nl;
         }
     }
-    string cmd("objToVTK " + fName + " " + fName.lessExt() + ".vtk");
-    Pout<< "cmd:" << cmd << endl;
-    system(cmd);
+    str.flush();
+
+    DynamicList<string> cmd(3);
+    cmd.append("objToVTK");
+    cmd.append(fName);
+    cmd.append(fName.lessExt() + ".vtk");
+
+    Pout<< "cmd: objToVTK " << fName.c_str() << endl;
+    Foam::system(cmd);
 }
 
 

src/OSspecific/POSIX/POSIX.C

@@ -3,7 +3,7 @@
   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
    \\    /   O peration     |
     \\  /    A nd           | Copyright (C) 2011-2016 OpenFOAM Foundation
-     \\/     M anipulation  |
+     \\/     M anipulation  | Copyright (C) 2016 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -38,6 +38,8 @@ Description
 #include "timer.H"
 #include "IFstream.H"
 #include "DynamicList.H"
+#include "CStringList.H"
+#include "SubList.H"
 
 #include <fstream>
 #include <cstdlib>
@@ -49,6 +51,7 @@ Description
 #include <pwd.h>
 #include <errno.h>
 #include <sys/types.h>
+#include <sys/wait.h>
 #include <sys/stat.h>
 #include <sys/socket.h>
 #include <netdb.h>
@@ -1210,9 +1213,153 @@ bool Foam::ping(const string& hostname, const label timeOut)
 }
 
 
+namespace Foam
+{
+//! \cond fileScope
+static int waitpid(const pid_t pid)
+{
+    // child status, return code from the exec etc.
+    int status = 0;
+
+    // in parent - blocking wait
+    // modest treatment of signals (in child)
+    // treat 'stopped' like exit (suspend/continue)
+    while (true)
+    {
+        pid_t wpid = ::waitpid(pid, &status, WUNTRACED);
+
+        if (wpid == -1)
+        {
+            FatalErrorInFunction
+                << "some error occurred in child"
+                << exit(FatalError);
+            break;
+        }
+
+        if (WIFEXITED(status))
+        {
+            // child exited, get its return status
+            return WEXITSTATUS(status);
+        }
+
+        if (WIFSIGNALED(status))
+        {
+            // child terminated by some signal
+            return WTERMSIG(status);
+        }
+
+        if (WIFSTOPPED(status))
+        {
+            // child stopped by some signal
+            return WSTOPSIG(status);
+        }
+
+        FatalErrorInFunction
+            << "programming error, status from waitpid() not handled: "
+            << status
+            << exit(FatalError);
+    }
+
+    return -1;  // should not happen
+}
+//! \endcond
+}
+
+
 int Foam::system(const std::string& command)
 {
-    return ::system(command.c_str());
+    if (command.empty())
+    {
+        // Treat an empty command as a successful no-op.
+        // From 'man sh' POSIX (man sh):
+        //   "If the command_string operand is an empty string,
+        //    sh shall exit with a zero exit status."
+        return 0;
+    }
+
+    pid_t child_pid = ::vfork();   // NB: vfork, not fork!
+    if (child_pid == -1)
+    {
+        FatalErrorInFunction
+            << "vfork() failed for system command " << command
+            << exit(FatalError);
+    }
+
+    if (child_pid == 0)
+    {
+        // in child
+
+        // execl uses the current environ
+        (void) ::execl
+        (
+            "/bin/sh",          // Path of the shell
+            "sh",               // Command-name (name for the shell)
+            "-c",               // Read commands from the command_string operand.
+            command.c_str(),    // Command string
+            reinterpret_cast<char *>(0)
+        );
+
+        // obviously failed, since exec should not return at all
+        FatalErrorInFunction
+            << "exec failed: " << command
+            << exit(FatalError);
+    }
+
+
+    // in parent - blocking wait
+    return waitpid(child_pid);
+}
+
+
+int Foam::system(const Foam::UList<Foam::string>& command)
+{
+    const int argc = command.size();
+
+    if (!argc)
+    {
+        // Treat an empty command as a successful no-op.
+        // For consistency with POSIX (man sh) behaviour for (sh -c command),
+        // which is what is mostly being replicated here.
+        return 0;
+    }
+
+    // NB: use vfork, not fork!
+    // vfork behaves more like a thread and avoids copy-on-write problems
+    // triggered by fork.
+    // The normal system() command has a fork buried in it that causes
+    // issues with infiniband and openmpi etc.
+    pid_t child_pid = ::vfork();
+    if (child_pid == -1)
+    {
+        FatalErrorInFunction
+            << "vfork() failed for system command " << command[0]
+            << exit(FatalError);
+    }
+
+    if (child_pid == 0)
+    {
+        // in child:
+        // Need command and arguments separately.
+        // args is a NULL-terminated list of c-strings
+
+        CStringList args(SubList<string>(command, 0));
+        if (argc > 1)
+        {
+            args.reset(SubList<string>(command, argc-1, 1));
+        }
+
+        // execvp uses the current environ
+        (void) ::execvp(command[0].c_str(), args.strings());
+
+        // obviously failed, since exec should not return at all
+        FatalErrorInFunction
+            << "exec(" << command[0] << ", ...) failed"
+            << exit(FatalError);
+    }
+
+
+    // in parent - blocking wait
+    return waitpid(child_pid);
 }
 
 

src/OpenFOAM/db/dynamicLibrary/dynamicCode/dynamicCode.C

@@ -3,7 +3,7 @@
   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
    \\    /   O peration     |
     \\  /    A nd           | Copyright (C) 2011-2015 OpenFOAM Foundation
-     \\/     M anipulation  |
+     \\/     M anipulation  | Copyright (C) 2016 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -493,10 +493,17 @@ bool Foam::dynamicCode::copyOrCreateFiles(const bool verbose) const
 
 bool Foam::dynamicCode::wmakeLibso() const
 {
-    const Foam::string wmakeCmd("wmake -s libso " + this->codePath());
-    Info<< "Invoking " << wmakeCmd << endl;
+    DynamicList<string> cmd(4);
+    cmd.append("wmake");
+    cmd.append("-s");
+    cmd.append("libso");
+    cmd.append(this->codePath());
 
-    if (Foam::system(wmakeCmd))
+    // NOTE: could also resolve wmake command explicitly
+    //   cmd[0] = stringOps::expand("$WM_PROJECT_DIR/wmake/wmake");
+
+    Info<< "Invoking wmake libso " << this->codePath().c_str() << endl;
+    if (Foam::system(cmd))
     {
         return false;
     }

src/OpenFOAM/global/argList/argList.C

@@ -1170,7 +1170,7 @@ void Foam::argList::displayDoc(bool source) const
 
         Info<< "Show documentation: " << docBrowser.c_str() << endl;
 
-        system(docBrowser);
+        Foam::system(docBrowser);
     }
     else
     {

src/OpenFOAM/include/OSspecific.H

@@ -37,6 +37,7 @@ SourceFiles
 #define OSspecific_H
 
 #include "fileNameList.H"
+#include "stringList.H"
 
 #include <sys/types.h>
 
@@ -209,9 +210,15 @@ bool ping(const string&, const label port, const label timeOut);
 //- Check if machine is up by pinging port 22 (ssh) and 222 (rsh)
 bool ping(const string&, const label timeOut=10);
 
-//- Execute the specified command
+//- Execute the specified command via the shell.
+//  Uses vfork/execl internally.
+//  Where possible, use the list version instead.
 int system(const std::string& command);
 
+//- Execute the specified command with arguments.
+//  Uses vfork/execvp internally
+int system(const UList<string>& command);
+
 //- Open a shared library. Return handle to library. Print error message
 //  if library cannot be loaded (check = true)
 void* dlOpen(const fileName& lib, const bool check = true);

src/OpenFOAM/primitives/strings/lists/CStringList.H

@@ -0,0 +1,175 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | Copyright (C) 2016 OpenCFD Ltd.
+     \\/     M anipulation  |
+-------------------------------------------------------------------------------
+License
+    This file is part of OpenFOAM.
+
+    OpenFOAM 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 3 of the License, or
+    (at your option) any later version.
+
+    OpenFOAM 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 OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
+
+Class
+    Foam::CStringList
+
+Description
+    An adapter for copying a list of C++ strings into a list of C-style
+    strings for passing to C code that expects argc/argv parameters.
+
+    In addition to providing a C-compatible list of C-strings,
+    the string lists are flattened into a single string of data that can be
+    also be passed en mass.
+
+    Example use:
+    \code
+        wordList myStrings;  ...
+        CStringList cstr(myStrings);
+
+        // pass as argc, argv:
+        someMain(cstr.size(), cstr.strings());
+
+        // access the raw characters:
+        os.write(cstr.data(), cstr.length());
+    \endcode
+
+\*---------------------------------------------------------------------------*/
+
+#ifndef CStringList_H
+#define CStringList_H
+
+#include "fileNameList.H"
+#include "stringList.H"
+#include "wordList.H"
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+namespace Foam
+{
+
+/*---------------------------------------------------------------------------*\
+                         Class CStringList Declaration
+\*---------------------------------------------------------------------------*/
+
+class CStringList
+{
+    // Private data
+
+        //- Number of strings
+        int argc_;
+
+        //- Overall length of the raw content
+        //  Does not include the final nul-character
+        size_t len_;
+
+        //- List of strings, including trailing NULL pointer
+        char** argv_;
+
+        //- Flattened content with interspersed nul-characters
+        char* data_;
+
+
+    // Private Member Functions
+
+        //- Disallow default bitwise copy construct
+        CStringList(const CStringList&) = delete;
+
+        //- Disallow default bitwise assignment
+        void operator=(const CStringList&) = delete;
+
+
+public:
+
+    // Constructors
+
+        //- Construct empty, adding content later (via reset).
+        inline CStringList();
+
+
+        //- Construct from a list of strings
+        //  Copies the input characters.
+        template<class StringType>
+        CStringList(const UList<StringType>& input);
+
+
+    //- Destructor
+    inline ~CStringList();
+
+
+    // Public Members
+
+        //- Count the number of parameters until the first NULL pointer.
+        //  Return 0 if argv is NULL.
+        static inline int count(const char * const argv[]);
+
+
+    // Access
+
+        //- Return the number of C-strings (ie, argc)
+        inline int size() const;
+
+        //- Return the list of C-strings (ie, argv)
+        //  The position at argc is a NULL pointer
+        inline char** strings() const;
+
+
+        //- Overall length of the flattened character (data) content
+        inline size_t length() const;
+
+        //- The flattened character content, with interspersed nul-chars
+        inline char* data() const;
+
+
+    // Edit
+
+        //- Clear contents and free memory
+        inline void clear();
+
+        //- Copy the input list of strings.
+        template<class StringType>
+        void reset(const UList<StringType>& input);
+
+
+    // Other
+
+        //- Create a list from argc/argv parameters.
+        //  A null pointer for argv is permissible when argc is zero.
+        template<class StringType>
+        static List<StringType> asList(int argc, const char * const argv[]);
+
+        //- Create a list from a NULL-terminated list of argv parameters.
+        //  A null pointer for argv is permissible.
+        template<class StringType>
+        static inline List<StringType> asList(const char * const argv[]);
+
+};
+
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+} // End namespace Foam
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+#include "CStringListI.H"
+
+#ifdef NoRepository
+#   include "CStringListTemplates.C"
+#endif
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+#endif
+
+// ************************************************************************* //

src/OpenFOAM/primitives/strings/lists/CStringListI.H

@@ -0,0 +1,106 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | Copyright (C) 2016 OpenCFD Ltd.
+     \\/     M anipulation  |
+-------------------------------------------------------------------------------
+License
+    This file is part of OpenFOAM.
+
+    OpenFOAM 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 3 of the License, or
+    (at your option) any later version.
+
+    OpenFOAM 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 OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
+
+\*---------------------------------------------------------------------------*/
+
+// * * * * * * * * * * * * Static Member Functions * * * * * * * * * * * * * //
+
+inline int Foam::CStringList::count(const char * const argv[])
+{
+    int nElem = 0;
+    if (argv)
+    {
+        while (argv[nElem])
+        {
+            ++nElem;
+        }
+    }
+
+    return nElem;
+}
+
+
+// * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
+
+inline Foam::CStringList::CStringList()
+:
+    argc_(0),
+    len_(0),
+    argv_(0),
+    data_(0)
+{}
+
+
+// * * * * * * * * * * * * * * * * Destructor  * * * * * * * * * * * * * * * //
+
+inline Foam::CStringList::~CStringList()
+{
+    clear();
+}
+
+
+// * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //
+
+inline void Foam::CStringList::clear()
+{
+    argc_ = 0;
+    len_  = 0;
+
+    if (data_)
+    {
+        delete[] data_;
+        data_ = 0;
+    }
+    if (argv_)
+    {
+        delete[] argv_;
+        argv_ = 0;
+    }
+}
+
+
+inline int Foam::CStringList::size() const
+{
+    return argc_;
+}
+
+
+inline size_t Foam::CStringList::length() const
+{
+    return len_;
+}
+
+
+inline char** Foam::CStringList::strings() const
+{
+    return argv_;
+}
+
+
+inline char* Foam::CStringList::data() const
+{
+    return data_;
+}
+
+
+// ************************************************************************* //

src/OpenFOAM/primitives/strings/lists/CStringListTemplates.C

@@ -0,0 +1,115 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | Copyright (C) 2016 OpenCFD Ltd.
+     \\/     M anipulation  |
+-------------------------------------------------------------------------------
+License
+    This file is part of OpenFOAM.
+
+    OpenFOAM 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 3 of the License, or
+    (at your option) any later version.
+
+    OpenFOAM 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 OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
+
+\*---------------------------------------------------------------------------*/
+
+// * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
+
+template<class StringType>
+Foam::CStringList::CStringList
+(
+    const UList<StringType>& input
+)
+:
+    argc_(0),
+    len_(0),
+    argv_(0),
+    data_(0)
+{
+    reset(input);
+}
+
+
+// * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //
+
+template<class StringType>
+void Foam::CStringList::reset
+(
+    const UList<StringType>& input
+)
+{
+    clear();
+
+    argc_ = input.size();
+    forAll(input, argI)
+    {
+        len_ += input[argI].size();
+        ++len_;  // nul terminator for C-strings
+    }
+
+    argv_ = new char*[argc_+1];
+    argv_[argc_] = NULL; // extra terminator
+
+    if (argc_ > 0)
+    {
+        // allocation includes final nul terminator,
+        // but overall count does not
+        data_ = new char[len_--];
+
+        char* ptr = data_;
+        forAll(input, argI)
+        {
+            argv_[argI] = ptr;
+
+            const std::string& str =
+                static_cast<const std::string&>(input[argI]);
+
+            for
+            (
+                std::string::const_iterator iter = str.begin();
+                iter != str.end();
+                ++iter
+            )
+            {
+                *(ptr++) = *iter;
+            }
+            *(ptr++) = '\0';
+        }
+    }
+}
+
+
+template<class StringType>
+Foam::List<StringType>
+Foam::CStringList::asList(int argc, const char * const argv[])
+{
+    List<StringType> lst(argc);
+
+    for (int i=0; i < argc; ++i)
+    {
+        lst[i] = argv[i];
+    }
+
+    return lst;
+}
+
+
+template<class StringType>
+Foam::List<StringType>
+Foam::CStringList::asList(const char * const argv[])
+{
+    return asList<StringType>(count(argv), argv);
+}
+
+
+// ************************************************************************* //

src/postProcessing/functionObjects/systemCall/controlDict

@@ -62,14 +62,15 @@ functions
         // called at the end of the run
         endCalls
         (
-            "echo \*\*\* writing .bashrc \*\*\*"
-            "cat ~/.bashrc"
-            "echo \*\*\* done \*\*\*"
+            // Note: single quotes to avoid shell expansion
+            "echo '*** listing ~/.bashrc ***'"
+            "cat ~/.bashrc; echo '*** done ***'"
         );
 
-        // called every ouput time
+        // called every output time
         writeCalls
         (
+            // Note: can also backslash to escape shell meta-characters
             "echo \*\*\* writing data \*\*\*"
         );
     }

src/thermophysicalModels/radiation/radiationModels/solarLoad/faceShading/faceShading.C

@@ -3,7 +3,7 @@
   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
    \\    /   O peration     |
     \\  /    A nd           | Copyright (C) 2015 OpenFOAM Foundation
-     \\/     M anipulation  |
+     \\/     M anipulation  | Copyright (C) 2016 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -62,9 +62,15 @@ void Foam::faceShading::writeRays
         vertI++;
         str << "l " << vertI-1 << ' ' << vertI << nl;
     }
-    string cmd("objToVTK " + fName + " " + fName.lessExt() + ".vtk");
-    Pout<< "cmd:" << cmd << endl;
-    system(cmd);
+    str.flush();
+
+    DynamicList<string> cmd(3);
+    cmd.append("objToVTK");
+    cmd.append(fName);
+    cmd.append(fName.lessExt() + ".vtk");
+
+    Pout<< "cmd: objToVTK " << fName.c_str() << endl;
+    Foam::system(cmd);
 }