Installation of GPS Correlate
=============================
To build, you will need these prerequisites:

* The Exiv2 library (C++ EXIF tag handling): https://www.exiv2.org/
  (ver. 0.27.4 or newer is required for time zone tag support)
* libxml2 (XML parsing): http://www.xmlsoft.org/
* pkgconfig: https://pkg-config.freedesktop.org/
* make, such as GNU makes: https://www.gnu.org/software/make/make.html
* GTK+ 2 or 3 (only if compiling the GUI)s: https://www.gtk.org
* xsltproc (only for building the man page): http://xmlsoft.org/XSLT/
  with manpages/docbook.xsl properly installed from
  https://docbook.sourceforge.net/ or an OS package (often named something like
  docbook-xsl or docbook-style-xsl)
* intltool (only for rebuilding the AppStream metadata file)
* exiv2 CLI (only for running the test suite)

You can build the command line version and the GUI together simply with:
  make
and install it with:
  sudo make install
Run the regression test suite with:
  make check

The default build process will try to link against GTK3.
To force building against GTK2 run:

  make GTK=2

If the compiler can't find the necessary libraries, then set the
PKG_CONFIG_PATH environment variable to the location of the .pc files first.

To build only the command-line tool without the GTK dependencies, do:
  make gpscorrelate
In both cases, pkg-config must be available to determine the compilation
arguments for libxml2 and exiv2.

gpscorrelate uses only standard features available in C99, C++11 and POSIX.
Some C environments may not provide all the necessary features, and some
environments may require compiling with the make command-line argument
CFLAGS='-D_POSIX_C_SOURCE=200809L' to enable them.  Alternately, you can
compile gpscorrelate entirely with a C++ toolchain by compiling with make
CC='$(CXX)'

gpscorrelate comes translated into a number of languages, but support is not
enabled by default as the gettext function is not universally available.
To enable foreign language support, compile with
"make CFLAGS=-DENABLE_NLS" (and LIBS=-lintl if required) and use the
additional command "sudo make install-po" to install the message catalogs.
Note that GNU make is required for this step.
