Changed code so that it will be compatible with c++.

1. Added #ifdef extern "C" to public header files.
2. Changed variables that are key words in c++, to different names (like ns instead of namespace).
3. Changed char* to const char* for constant strings.

test/test_c++.sh

@@ -0,0 +1,114 @@
+#!/usr/bin/env bash
+# Tests cpp compatibility with clixon
+
+# Magic line must be first in script (see README.md)
+s="$_" ; . ./lib.sh || if [ "$s" = $0 ]; then exit 0; else return 0; fi
+
+cfile=$dir/c++.cpp
+
+CXX=g++
+
+cat<<EOF > $cfile
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <syslog.h>
+#include <unistd.h>
+#include <sys/stat.h>
+#include <sys/param.h>
+
+#include <cligen/cligen.h>
+#include <clixon/clixon.h>
+#include <clixon/clixon_netconf.h>
+
+/*! Plugin start
+ * Called once everything has been initialized, right before
+ * the main event loop is entered.
+ */
+int
+plugin_start(clicon_handle h)
+{
+    return 0;
+}
+
+int
+plugin_exit(clicon_handle h)
+{
+    return 0;
+}
+
+/*! Local example netconf rpc callback
+ */
+int
+netconf_client_rpc(clicon_handle h,
+		   cxobj        *xe,
+		   cbuf         *cbret,
+		   void         *arg,
+		   void         *regarg)
+{
+    int    retval = -1;
+    cxobj *x = NULL;
+    char  *ns;
+
+    /* get namespace from rpc name, return back in each output parameter */
+    if ((ns = xml_find_type_value(xe, NULL, (char*)"xmlns", CX_ATTR)) == NULL){
+	clicon_err(OE_XML, ENOENT, "No namespace given in rpc %s", xml_name(xe));
+	goto done;
+    }
+    cprintf(cbret, "<rpc-reply>");
+    if (!xml_child_nr_type(xe, CX_ELMNT))
+	cprintf(cbret, "<ok/>");
+    else while ((x = xml_child_each(xe, x, CX_ELMNT)) != NULL) {
+	    if (xmlns_set(x, NULL, ns) < 0)
+		goto done;
+	    if (clicon_xml2cbuf(cbret, x, 0, 0, -1) < 0)
+		goto done;
+	}
+    cprintf(cbret, "</rpc-reply>");
+    retval = 0;
+ done:
+    return retval;
+
+    return 0;
+}
+
+clixon_plugin_api * clixon_plugin_init(clicon_handle h);
+
+static struct clixon_plugin_api api;
+
+void api_initialization(void)
+{
+    strcpy(api.ca_name, "c++ netconf test");     /* name */
+    api.ca_init = clixon_plugin_init;            /* init */
+    api.ca_start = plugin_start;                 /* start */
+    api.ca_exit = plugin_exit;                   /* exit */
+};
+
+/*! Netconf plugin initialization
+ * @param[in]  h    Clixon handle
+ * @retval     NULL Error with clicon_err set
+ * @retval     api  Pointer to API struct
+ */
+clixon_plugin_api *
+clixon_plugin_init(clicon_handle h)
+{
+
+	api_initialization();
+
+    clicon_debug(1, (char*)"%s netconf", __FUNCTION__);
+    /* Register local netconf rpc client (note not backend rpc client) */
+    if (rpc_callback_register(h, netconf_client_rpc, NULL,
+			      (char*)"urn:example:clixon", (char*)"client-rpc") < 0)
+	return NULL;
+    return &api;
+}
+
+EOF
+
+new "C++ compile"
+expectpart "$($CXX -g -Wall -rdynamic -fPIC -shared $cfile -o c++.o)" 0 ""
+
+rm -f c++.o
+rm -rf $dir
+