get the version number from the cmake project

CMakeLists.txt

@@ -12,6 +12,9 @@ set(CMAKE_CXX_STANDARD_REQUIRED ON)
 include(FindPkgConfig)
 pkg_check_modules(OGG REQUIRED ogg)
 
+configure_file(config.h.in config.h @ONLY)
+include_directories(${CMAKE_CURRENT_BINARY_DIR})
+
 add_executable(opustags opustags.cc)
 target_compile_options(opustags PUBLIC ${OGG_CFLAGS})
 target_link_libraries(opustags PUBLIC ${OGG_LIBRARIES})

config.h.in

@@ -0,0 +1,2 @@
+#cmakedefine PROJECT_NAME "@PROJECT_NAME@"
+#cmakedefine PROJECT_VERSION "@PROJECT_VERSION@"

opustags.cc

@@ -1,3 +1,5 @@
+#include <config.h>
+
 #include <errno.h>
 #include <getopt.h>
 #include <limits.h>
@@ -165,7 +167,7 @@ int write_page(ogg_page *og, FILE *stream){
     return 0;
 }
 
-const char *version = "opustags version 1.1.1\n";
+const char *version = PROJECT_NAME " version " PROJECT_VERSION "\n";
 
 const char *usage =
     "Usage: opustags --help\n"

t/meta.t

@@ -4,22 +4,23 @@
 use strict;
 use warnings;
 
-use Test::More tests => 6;
+use Test::More tests => 7;
 
 my $opustags = './opustags';
-chomp(my $version = `git describe --tags --abbrev=0`);
-
 BAIL_OUT("$opustags does not exist or is not executable") if (! -x $opustags);
 
+chomp(my $version = `$opustags --help | head -n 1`);
+like($version, qr/^opustags version \d+\.\d+\.\d+$/, 'get the version string');
+
 is(`$opustags`, <<"EOF", 'no options show the usage');
-opustags version $version
+$version
 Usage: opustags --help
        opustags [OPTIONS] FILE
        opustags OPTIONS FILE -o FILE
 EOF
 
 my $help = <<"EOF";
-opustags version $version
+$version
 
 Usage: opustags --help
        opustags [OPTIONS] FILE