use common main function that allows handling of common command line flags.

unittest/c-library/test_main.h

@@ -0,0 +1,33 @@
+/* -*- c++ -*- ----------------------------------------------------------
+   LAMMPS - Large-scale Atomic/Molecular Massively Parallel Simulator
+   http://lammps.sandia.gov, Sandia National Laboratories
+   Steve Plimpton, sjplimp@sandia.gov
+
+   Copyright (2003) Sandia Corporation.  Under the terms of Contract
+   DE-AC04-94AL85000 with Sandia Corporation, the U.S. Government retains
+   certain rights in this software.  This software is distributed under
+   the GNU General Public License.
+
+   See the README file in the top-level LAMMPS directory.
+------------------------------------------------------------------------- */
+
+#ifndef TEST_MAIN_H
+#define TEST_MAIN_H
+
+extern bool verbose;
+
+#define EXPECT_FP_LE_WITH_EPS(val1, val2, eps)                \
+    do {                                                      \
+        const double diff = fabs(val1 - val2);                \
+        const double div  = std::min(fabs(val1), fabs(val2)); \
+        const double err  = (div == 0.0) ? diff : diff / div; \
+        EXPECT_PRED_FORMAT2(::testing::DoubleLE, err, eps);   \
+    } while (0);
+
+#endif
+
+#if defined _WIN32
+static const char PATH_SEP = '\\';
+#else
+static const char PATH_SEP = '/';
+#endif