fixes #254 nngcat should have a --version option

We only add a basic --version (also -V). I'm still trying to figure
out how to convince cmake to emit its compilation flags into a file
where we can use them for output.

4 files changed, 25 insertions, 3 deletions

diff --git a/docs/man/nngcat.adoc b/docs/man/nngcat.adoc
index 49e4b05a..e5528536 100644
--- a/docs/man/nngcat.adoc
+++ b/docs/man/nngcat.adoc
@@ -17,6 +17,8 @@ nngcat - command line access to Scalabity Protocols
 
 *nngcat* --help
 
+*nngcat* --version
+
 *nngcat* [_OPTION_]... 
 
 == DESCRIPTION
@@ -41,6 +43,8 @@ equa
 === Generic
 *-h, --help*::
   Get usage help.
+*-V, --version*::
+  Print the version and exit.
 *-v, --verbose*::
   Select verbose operation.
 *-q, --silent*::
diff --git a/src/nng.c b/src/nng.c
index b7255904..19b33220 100644
--- a/src/nng.c
+++ b/src/nng.c
@@ -8,6 +8,7 @@
 // found online at https://opensource.org/licenses/MIT.
 //
 
+#include "nng.h"
 #include "core/nng_impl.h"
 
 // This file provides the "public" API.  This is a thin wrapper around
@@ -1212,3 +1213,13 @@ nng_url_clone(nng_url **dstp, const nng_url *src)
 {
 	return (nni_url_clone(dstp, src));
 }
+
+#define xstr(a) str(a)
+#define str(a) #a
+
+const char *
+nng_version(void)
+{
+	return (xstr(NNG_MAJOR_VERSION) "." xstr(NNG_MINOR_VERSION) "." xstr(
+	    NNG_PATCH_VERSION));
+}
diff --git a/src/nng.h b/src/nng.h
index e2cdb8fa..7615785d 100644
--- a/src/nng.h
+++ b/src/nng.h
@@ -47,9 +47,9 @@ extern "C" {
 // may not necessarily match the ABI versions. Right now at
 // version 0, you should not be making any forward compatibility
 // assumptions.
-#define	NNG_MAJOR_VERSION	0
-#define	NNG_MINOR_VERSION	5
-#define	NNG_PATCH_VERSION	0
+#define NNG_MAJOR_VERSION 0
+#define NNG_MINOR_VERSION 5
+#define NNG_PATCH_VERSION 0
 
 // Types common to nng.
 typedef uint32_t            nng_socket;
@@ -698,6 +698,8 @@ NNG_DECL void nng_url_free(nng_url *);
 // nng_url_clone clones a URL structure.
 NNG_DECL int nng_url_clone(nng_url **, const nng_url *);
 
+// nng_version returns the library version as a human readable string.
+NNG_DECL const char *nng_version(void);
 #ifdef __cplusplus
 }
 #endif
diff --git a/tools/nngcat/nngcat.c b/tools/nngcat/nngcat.c
index 2f5ef563..064e4635 100644
--- a/tools/nngcat/nngcat.c
+++ b/tools/nngcat/nngcat.c
@@ -96,6 +96,7 @@ enum options {
 	OPT_CACERT,
 	OPT_KEYFILE,
 	OPT_CERTFILE,
+	OPT_VERSION,
 };
 
 static nng_optspec opts[] = {
@@ -179,6 +180,7 @@ static nng_optspec opts[] = {
 	    .o_val   = OPT_CERTFILE,
 	    .o_arg   = true,
 	},
+	{ .o_name = "version", .o_short = 'V', .o_val = OPT_VERSION },
 
 	// Sentinel.
 	{ .o_name = NULL, .o_val = 0 },
@@ -784,6 +786,9 @@ main(int ac, const char **av)
 		case OPT_INSECURE:
 			insecure = 1;
 			break;
+		case OPT_VERSION:
+			printf("%s\n", nng_version());
+			exit(0);
 		}
 	}
 	switch (rv) {