adding SNMP example

C/sockets/UDP/SNMP/snmp.c

@@ -0,0 +1,48 @@
+// gcc `net-snmp-config --cflags` `net-snmp-config --libs` `net-snmp-config --external-libs` snmp.c -o snmp
+
+#include <net-snmp/net-snmp-config.h>
+#include <net-snmp/net-snmp-includes.h>
+#include <string.h>
+
+int main(int argc, char ** argv)
+{
+	struct snmp_session session; 
+	struct snmp_session *sess_handle;
+	struct snmp_pdu *pdu;
+	struct snmp_pdu *response;
+	struct variable_list *vars;
+
+	oid id_oid[MAX_OID_LEN];
+
+	size_t id_len = MAX_OID_LEN;
+
+	if(argv[1] == NULL){
+		printf("Please supply a hostname\n");
+		exit(1);
+	}
+
+	init_snmp("APC Check");
+
+	snmp_sess_init( &session );
+	session.version = SNMP_VERSION_2c;
+	session.community = "public";
+	session.community_len = strlen(session.community);
+	session.peername = argv[1];
+	sess_handle = snmp_open(&session);
+
+	pdu = snmp_pdu_create(SNMP_MSG_GET);
+
+	read_objid("SNMPv2-MIB::sysDescr.0", id_oid, &id_len);
+	snmp_add_null_var(pdu, id_oid, id_len);
+
+	if ((snmp_synch_response(sess_handle, pdu, &response)) == 0)
+		for(vars = response->variables; vars; vars = vars->next_variable)
+			print_value(vars->name, vars->name_length, vars);
+	else
+		printf("NO SNMP\n");
+
+	snmp_free_pdu(response);
+	snmp_close(sess_handle);
+
+	return (0);
+}