Merge pull request #1984 in HDFFV/hdf5 from ~DYOUNG/netbsd:develop to develop

* commit '0b721858e46a317c370a24115032d5be41688f67':
  Make these scripts relocatable again: derive a relative path for the original installation prefix from the examples prefix.  Use that relative path to locate the current installation prefix, always.  Fall back to an absolute installation prefix if the relative path cannot be derived.
  Get the path to prefix right: needs a ../ to back out of subdirectory c/.
  Make this script relocatable again: derive a relative path for the original installation prefix from the examples prefix.  Use that relative path to locate the current installation prefix, always.  Fall back to an absolute installation prefix if the relative path cannot be derived.
  Let us override the examples directory using --with-examplesdir=DIR. This is handy for NetBSD where HDF5 examples are installed by convention in $prefix/share/examples/hdf5/ rather than in ${prefix}/share/hdf5_examples/, which is the HDF5 default.
  Follow longstanding execv convention for compatibility with NetBSD.
  Under the examples directories, always find the installed HDF5 executables and scripts using @prefix@ instead of a relative path, because the number of ../ in the relative path will be different on NetBSD than on other systems.
  Make the HDF5 configure script grok NetBSD.
  For portability, insulate the HDF5 library from some system macros.
  Not every system has perl installed in /usr/bin/, so change the shebang (#!) line to `/usr/bin/env perl` to locate perl on the PATH.
  For portability, use the POSIX sh(1) string-comparison operator `=` instead of `==`.

2 files changed, 27 insertions, 4 deletions

diff --git a/c++/examples/Makefile.am b/c++/examples/Makefile.am
index 51ab8e3..0648504 100644
--- a/c++/examples/Makefile.am
+++ b/c++/examples/Makefile.am
@@ -49,8 +49,8 @@ CXX_API=yes
 
 # Where to install examples
 # Note: no '/' after DESTDIR.  Explanation in commence.am
-EXAMPLEDIR=${DESTDIR}$(exec_prefix)/share/hdf5_examples/c++
-EXAMPLETOPDIR=${DESTDIR}$(exec_prefix)/share/hdf5_examples
+EXAMPLEDIR=$(examplesdir)/c++
+EXAMPLETOPDIR=$(examplesdir)
 
 # How to build programs using h5c++
 $(EXTRA_PROG): $(H5CPP)
diff --git a/c++/examples/run-c++-ex.sh.in b/c++/examples/run-c++-ex.sh.in
index d975924..08e9633 100644
--- a/c++/examples/run-c++-ex.sh.in
+++ b/c++/examples/run-c++-ex.sh.in
@@ -18,7 +18,7 @@
 # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # #
 #                                                                               #
 # This script will compile and run the c++ examples from source files           #
-# installed in .../share/hdf5_examples/c++ using h5c++.  The                    #
+# installed in @examplesdir@/c++ using h5c++.  The                              #
 # order for running programs with RunTest in the MAIN section below is taken    #
 # from the Makefile.  The order is important since some of the test programs    #
 # use data files created by earlier test programs.  Any future additions should #
@@ -30,9 +30,32 @@
 EXIT_SUCCESS=0
 EXIT_FAILURE=1
 
+#
+# Try to derive the path to the installation $prefix established
+# by ./configure relative to the examples directory established by
+# ./configure.  If successful, set `prefix_relto_examplesdir` to the
+# relative path.  Otherwise, set `prefix_relto_examplesdir` to the
+# absolute installation $prefix.
+#
+# This script uses the value of `prefix` in the user's environment, if
+# it is set, below.  The content of $() is evaluated in a sub-shell, so
+# if `prefix` is set in the user's environment, the shell statements in
+# $() won't clobbered it.
+#
+prefix_relto_examplesdir=$(
+prefix=@prefix@
+examplesdir=@examplesdir@
+if [ ${examplesdir##${prefix}/} != ${examplesdir} ]; then
+	echo $(echo ${examplesdir##${prefix}/} | \
+	    sed -E 's,[^/]+,..,g')
+else
+	echo $prefix
+fi
+)
+
 # Where the tool is installed.
 # default is relative path to installed location of the tools
-prefix="${prefix:-../../..}"
+prefix="${prefix:-../${prefix_relto_examplesdir}}"
 AR="@AR@"
 RANLIB="@RANLIB@"
 H5TOOL="h5c++"                  # The tool name