[PATCH nftables v2 2/2] main: add more information to `nft -v`.

[Jeremy Sowden <jeremy@azazel.net>]

In addition to the package-version and release-name, output the CLI
implementation (if any) and whether mini-gmp was used, e.g.:

    $ ./src/nft -v
    nftables v0.9.2 (Scram)
      cli:          linenoise
      minigmp:      no

Signed-off-by: Jeremy Sowden <jeremy@azazel.net>
---
 src/Makefile.am |  3 +++
 src/main.c      | 28 ++++++++++++++++++++++++++--
 2 files changed, 29 insertions(+), 2 deletions(-)

diff --git a/src/Makefile.am b/src/Makefile.am
index 740c21f2cac8..54aed5efb7bb 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -13,6 +13,9 @@ endif
 if BUILD_XTABLES
 AM_CPPFLAGS += ${XTABLES_CFLAGS}
 endif
+if BUILD_MINIGMP
+AM_CPPFLAGS += -DHAVE_MINIGMP
+endif
 
 AM_CFLAGS = -Wall								\
 	    -Wstrict-prototypes -Wmissing-prototypes -Wmissing-declarations	\
diff --git a/src/main.c b/src/main.c
index f77d8a820a02..3334141eab35 100644
--- a/src/main.c
+++ b/src/main.c
@@ -154,6 +154,31 @@ static void show_help(const char *name)
 	name, DEFAULT_INCLUDE_PATH);
 }
 
+static void show_version(void)
+{
+	const char *cli, *minigmp;
+
+#if defined(HAVE_LIBREADLINE)
+	cli = "readline";
+#elif defined(HAVE_LIBLINENOISE)
+	cli = "linenoise";
+#else
+	cli = "no";
+#endif
+
+#if defined(HAVE_MINIGMP)
+	minigmp = "yes";
+#else
+	minigmp = "no";
+#endif
+
+	printf("%s v%s (%s)\n"
+	       "  cli:		%s\n"
+	       "  minigmp:	%s\n",
+	       PACKAGE_NAME, PACKAGE_VERSION, RELEASE_NAME,
+	       cli, minigmp);
+}
+
 static const struct {
 	const char		*name;
 	enum nft_debug_level	level;
@@ -213,8 +238,7 @@ int main(int argc, char * const *argv)
 			show_help(argv[0]);
 			exit(EXIT_SUCCESS);
 		case OPT_VERSION:
-			printf("%s v%s (%s)\n",
-			       PACKAGE_NAME, PACKAGE_VERSION, RELEASE_NAME);
+			show_version();
 			exit(EXIT_SUCCESS);
 		case OPT_CHECK:
 			nft_ctx_set_dry_run(nft, true);
-- 
2.23.0