+/*
+ * This file is part of the GROMACS molecular simulation package.
+ *
+ * Copyright (c) 2015, by the GROMACS development team, led by
+ * Mark Abraham, David van der Spoel, Berk Hess, and Erik Lindahl,
+ * and including many others, as listed in the AUTHORS file in the
+ * top-level source directory and at http://www.gromacs.org.
+ *
+ * GROMACS is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public License
+ * as published by the Free Software Foundation; either version 2.1
+ * of the License, or (at your option) any later version.
+ *
+ * GROMACS 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with GROMACS; if not, see
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+ */
+/*! \libinternal \file
+ * \brief
+ * Declares gmx::FileOutputRedirectorInterface.
+ *
+ * \author Teemu Murtola <teemu.murtola@gmail.com>
+ * \inlibraryapi
+ * \ingroup module_utility
+ */
+#ifndef GMX_UTILITY_FILEREDIRECTOR_H
+#define GMX_UTILITY_FILEREDIRECTOR_H
+
+#include <string>
+
+#include "gromacs/utility/file.h"
+
+namespace gmx
+{
+
+/*! \libinternal \brief
+ * Allows capturing `stdout` and file output from code that supports it.
+ *
+ * The calling code should take in this interface and use the File objects
+ * it returns for all output that needs to support this redirection.
+ * By default, the code can then use defaultFileOutputRedirector() in case no
+ * redirection is needed.
+ *
+ * This allows tests to capture the file output without duplicating the
+ * knowledge of which files are actually produced. With some further
+ * refactoring of the File class, this could support capturing the output into
+ * in-memory buffers as well, but for now the current capabilities are
+ * sufficient.
+ *
+ * \inlibraryapi
+ * \ingroup module_utility
+ */
+class FileOutputRedirectorInterface
+{
+ public:
+ virtual ~FileOutputRedirectorInterface();
+
+ /*! \brief
+ * Returns a File object to use for `stdout` output.
+ */
+ virtual File &standardOutput() = 0;
+ /*! \brief
+ * Returns a File object to use for output to a given file.
+ *
+ * \param[in] filename Requested file name.
+ */
+ virtual FileInitializer openFileForWriting(const char *filename) = 0;
+
+ //! Convenience method to open a file using an std::string path.
+ FileInitializer openFileForWriting(const std::string &filename)
+ {
+ return openFileForWriting(filename.c_str());
+ }
+};
+
+//! \cond libapi
+/*! \brief
+ * Returns default implementation for FileOutputRedirectorInterface.
+ *
+ * The returned implementation does not redirect anything, but just opens the
+ * files at requested locations.
+ *
+ * \ingroup module_utility
+ */
+FileOutputRedirectorInterface &defaultFileOutputRedirector();
+//! \endcond
+
+} // namespace gmx
+
+#endif