diff --git a/cxx4/tst_filter.sh b/cxx4/tst_filter.sh
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diff --git a/test_common.in b/test_common.in
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+# Copyright 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002,
+# 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013, 2014,
+# 2015, 2016, 2017, 2018
+# University Corporation for Atmospheric Research/Unidata.
+
+# See netcdf-c/COPYRIGHT file for more info.
+
+TOPSRCDIR='@abs_top_srcdir@'
+TOPBUILDDIR='@abs_top_builddir@'
+
+set -e
+
+# Figure out various locations in the src/build tree.
+# This is relatively fragile code and is essentially
+# specific to netcdf-c. It does, however, have the virtue
+# of isolating all this nonsense into one place.
+# This will get somewhat simplified (I hope) when
+# we move to a separate test_utilities directory
+
+# This code is intended to provide constants
+# for accessing various objects in the src/build
+# tree(s) across multiple ways of building netcdf-c.
+# Currently, the following build situations are supported.
+# 1. Autoconf with make check: the src and build trees are the same
+# 2. Autoconf with make distcheck: the src and build trees are distinct
+# 3. Cmake on a *nix platform using e.g. gcc:
+#    the src and build trees are distinct.
+# 4. Cmake on windows using cygwin or msys.
+#    The src and build trees are distinct.
+#
+# For now, an explicit build using the Visual C(++) compiler
+# is not supported. The big issue is the handling of executables
+# and the notion of a VS configuration/build type like Debug or Release.
+# When using VS, executables are placed in a subdirectory of the
+# build directory. That subdirectory is named by the configuration type.
+# Thus one finds ncdump.exe in $top_builddir/ncdump/Debug instead of
+# $top_builddir/ncdump. An additional issue is the extension of an
+# executable: .exe vs nothing. This code attempts to figure out which is used.
+#
+# For possible future fixes, a placeholder is left in place in the
+# following code named VS. If it were set to the build type, then,
+# in theory, this code would work with Visual C. It is disabled for now.
+#
+# The goal, then, of this common code is to set up some useful
+#constants for use in test shell scripts.
+# 1. srcdir - absolute path to the source dir (e.g. ${top_srcdir}/ncgen)
+# 2. top_srcdir - absolute path to the root of the source
+# 3. top_builddir - absolute path to the root of the build directory;
+#                   may be same as top_srcdir (e.g. #1).
+# 4. builddir - absolute path of th the directory into which generated
+#               stuff (.nc, .cdl, etc) is stored.
+# 5. execdir - absolute path of the directory into which executables are
+#              placed. For all but the VS case, execdir == builddir.
+#
+# The following are defined to support inter-directory references.
+# 6. NCDUMP - absolute path to the ncdump.exe executable
+# 7. NCCOPY - absolute path to the nccopy.exe executable
+# 8. NCGEN - absolute path to ncgen.exe
+# 9. NCGEN3 - absolute path to ncgen3.exe
+
+# Allow global set -x mechanism for debugging.
+if test "x$SETX" = x1 ; then set -x ; fi
+
+# We assume that TOPSRCDIR and TOPBUILDDIR are defined
+# At the top of this shell script
+top_srcdir="$TOPSRCDIR"
+top_builddir="$TOPBUILDDIR"
+
+# Currently not used, but left as a Visual Studio placeholder.
+# VS=Debug
+
+# srcdir may or may not be defined, but if not, then create it
+if test "x$srcdir" = x ; then
+  # we need to figure out our directory
+  # pick off the last component as the relative name of this directory
+  srcdir=`pwd`
+  current=`basename $srcdir`
+  srcdir="${top_srcdir}/$current"
+fi
+
+# We also assume we are executing in builddir
+builddir=`pwd`
+
+# execdir is an alias for builddir
+execdir="${builddir}"
+
+# pick off the last component as the relative name of this directory
+thisdir=`basename $srcdir`
+
+WD=`pwd`
+# Absolutize paths of interest
+cd $srcdir; srcdir=`pwd` ; cd $WD
+cd $top_srcdir; top_srcdir=`pwd` ; cd $WD
+cd $builddir; builddir=`pwd` ; cd $WD
+cd $top_builddir; top_builddir=`pwd` ; cd $WD
+cd $execdir; execdir=`pwd` ; cd $WD
+
+# If we have cygpath (which only exists under CYGWIN),
+# then try to normalize selected file paths.
+
+# For sun os
+export srcdir top_srcdir builddir top_builddir execdir
+
+# Figure out executable extension (probably a better way)
+if test -e "${top_builddir}/ncdump${VS}/ncdump.exe" ; then
+  ext=".exe"
+else
+  ext=""
+fi
+
+# We need to locate certain executables (and other things),
+# capture absolute paths, and make visible
+export NCDUMP="${top_builddir}/ncdump${VS}/ncdump${ext}"
+export NCCOPY="${top_builddir}/ncdump${VS}/nccopy${ext}"
+export NCGEN="${top_builddir}/ncgen${VS}/ncgen${ext}"
+export NCGEN3="${top_builddir}/ncgen3${VS}/ncgen3${ext}"
+
+# Temporary hacks (until we have a test_utils directory)
+# to locate certain specific test files
+ncgen3c0="${top_srcdir}/ncgen3/c0.cdl"
+ncgenc0="${top_srcdir}/ncgen/c0.cdl"
+ncgenc04="${top_srcdir}/ncgen/c0_4.cdl"
+
+# Make sure we are in builddir (not execdir)
+cd $builddir