From: Jeroen van Vianen <jeroenv@design.nl>

Attached patch will add a version() function to Postges, e.g.

template1=> select version();
version
------------------------------------------------------------
PostgreSQL 6.3.2 on i586-pc-linux-gnu, compiled by gcc 2.8.1
(1 row)

src/backend/utils/adt/version.c

@@ -0,0 +1,28 @@
+/*-------------------------------------------------------------------------
+ *
+ * version.c--
+ *   Returns the version string
+ *
+ * IDENTIFICATION
+ *
+ * $Header: /cvsroot/pgsql/src/backend/utils/adt/version.c,v 1.1 1998/04/29 12:38:05 scrappy Exp $
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#include "postgres.h"
+#include "version.h"
+
+
+text*  version(void);
+
+text*  version(void)
+{
+	int  n = strlen(PG_VERSION_STR) + VARHDRSZ;
+	text  *ret = (text *) palloc(n);
+
+	VARSIZE(ret) = n;
+	strcpy(VARDATA(ret), PG_VERSION_STR);
+
+	return ret;
+}