cli: implement TAB completion for connection and interface names

For commands like
nmcli -a dev disconnect
nmcli -a con up
...

cli/src/connections.c

@@ -71,6 +71,7 @@
 #define PROMPT_BOND_MASTER _("Bond master: ")
 #define PROMPT_TEAM_MASTER _("Team master: ")
 #define PROMPT_BRIDGE_MASTER _("Bridge master: ")
+#define PROMPT_CONNECTION _("Connection (name, UUID, or path): ")
 
 static const char *nmc_known_vpns[] =
 	{ "openvpn", "vpnc", "pptp", "openconnect", "openswan", "libreswan",
@@ -1963,10 +1964,8 @@ do_connection_up (NmCli *nmc, int argc, char **argv)
 
 	if (argc == 0) {
 		if (nmc->ask) {
-			line = nmc_readline (_("Connection (name, UUID, or path): "));
+			line = nmc_readline (PROMPT_CONNECTION);
 			name = line ? line : "";
-			// TODO: enhancement:  when just Enter is pressed (line is NULL), list
-			// available connections so that the user can select one
 		}
 	} else if (strcmp (*argv, "ifname") != 0) {
 		if (   strcmp (*argv, "id") == 0
@@ -2075,7 +2074,7 @@ do_connection_down (NmCli *nmc, int argc, char **argv)
 
 	if (argc == 0) {
 		if (nmc->ask) {
-			line = nmc_readline (_("Connection (name, UUID, or path): "));
+			line = nmc_readline (PROMPT_CONNECTION);
 			nmc_string_to_arg_array (line, "", &arg_arr, &arg_num);
 			arg_ptr = arg_arr;
 		}
@@ -8199,7 +8198,7 @@ do_connection_delete (NmCli *nmc, int argc, char **argv)
 
 	if (argc == 0) {
 		if (nmc->ask) {
-			line = nmc_readline (_("Connection (name, UUID, or path): "));
+			line = nmc_readline (PROMPT_CONNECTION);
 			nmc_string_to_arg_array (line, "", &arg_arr, &arg_num);
 			arg_ptr = arg_arr;
 		}
@@ -8375,12 +8374,53 @@ connection_editor_thread_func (gpointer data)
 	return NULL;
 }
 
+static char *
+gen_func_connection_names (char *text, int state)
+{
+	int i = 0;
+	GSList *iter;
+	const char **connections;
+	char *ret;
+
+	if (!nm_cli.system_connections)
+		return NULL;
+
+	connections = g_new (const char *, g_slist_length (nm_cli.system_connections) + 1);
+	for (iter = nm_cli.system_connections; iter; iter = g_slist_next (iter)) {
+		NMConnection *con = NM_CONNECTION (iter->data);
+		const char *id = nm_connection_get_id (con);
+		connections[i++] = id;
+	}
+	connections[i] = NULL;
+
+	ret = nmc_rl_gen_func_basic (text, state, connections);
+
+	g_free (connections);
+	return ret;
+}
+
 static char **
 nmcli_con_tab_completion (char *text, int start, int end)
 {
+	char **match_array = NULL;
+	CPFunction *generator_func = NULL;
+
 	/* Disable readline's default filename completion */
 	rl_attempted_completion_over = 1;
-	return NULL;
+
+	/* Disable appending space after completion */
+	rl_completion_append_character = '\0';
+
+	if (!is_single_word (rl_line_buffer))
+		return NULL;
+
+	if (g_strcmp0 (rl_prompt, PROMPT_CONNECTION) == 0)
+		generator_func = gen_func_connection_names;
+
+	if (generator_func)
+		match_array = rl_completion_matches (text, generator_func);
+
+	return match_array;
 }
 
 static NMCResultCode

cli/src/devices.c

@@ -66,6 +66,8 @@
 #include "common.h"
 #include "devices.h"
 
+/* define some prompts */
+#define PROMPT_INTERFACE _("Interface: ")
 
 /* Available fields for 'device status' */
 static NmcOutputField nmc_fields_dev_status[] = {
@@ -1383,7 +1385,7 @@ do_device_connect (NmCli *nmc, int argc, char **argv)
 
 	if (argc == 0) {
 		if (nmc->ask)
-			ifname = ifname_ask = nmc_readline (_("Interface: "));
+			ifname = ifname_ask = nmc_readline (PROMPT_INTERFACE);
 
 		if (!ifname_ask) {
 			g_string_printf (nmc->return_text, _("Error: No interface specified."));
@@ -1517,7 +1519,7 @@ do_device_disconnect (NmCli *nmc, int argc, char **argv)
 
 	if (argc == 0) {
 		if (nmc->ask)
-			ifname = ifname_ask = nmc_readline (_("Interface: "));
+			ifname = ifname_ask = nmc_readline (PROMPT_INTERFACE);
 
 		if (!ifname_ask) {
 			g_string_printf (nmc->return_text, _("Error: No interface specified."));
@@ -2559,12 +2561,73 @@ do_device_wimax (NmCli *nmc, int argc, char **argv)
 }
 #endif
 
+static gboolean
+is_single_word (const char* line)
+{
+	size_t n1, n2, n3;
+
+	n1 = strspn  (line,    " \t");
+	n2 = strcspn (line+n1, " \t\0") + n1;
+	n3 = strspn  (line+n2, " \t");
+
+	if (n3 == 0)
+		return TRUE;
+	else
+		return FALSE;
+}
+
+/* Global variable defined in nmcli.c */
+extern NmCli nm_cli;
+
+static char *
+gen_func_ifnames (char *text, int state)
+{
+	int i, j = 0;
+	const GPtrArray *devices;
+	const char **ifnames;
+	char *ret;
+
+	nm_cli.get_client (&nm_cli);
+	devices = nm_client_get_devices (nm_cli.client);
+	if (!devices || devices->len < 1)
+		return NULL;
+
+	ifnames = g_new (const char *, devices->len + 1);
+	for (i = 0; i < devices->len; i++) {
+		NMDevice *dev = g_ptr_array_index (devices, i);
+		const char *ifname = nm_device_get_iface (dev);
+		ifnames[j++] = ifname;
+	}
+	ifnames[j] = NULL;
+
+	ret = nmc_rl_gen_func_basic (text, state, ifnames);
+
+	g_free (ifnames);
+	return ret;
+}
+
 static char **
 nmcli_device_tab_completion (char *text, int start, int end)
 {
+	char **match_array = NULL;
+	CPFunction *generator_func = NULL;
+
 	/* Disable readline's default filename completion */
 	rl_attempted_completion_over = 1;
-	return NULL;
+
+	/* Disable appending space after completion */
+	rl_completion_append_character = '\0';
+
+	if (!is_single_word (rl_line_buffer))
+		return NULL;
+
+	if (g_strcmp0 (rl_prompt, PROMPT_INTERFACE) == 0)
+		generator_func = gen_func_ifnames;
+
+	if (generator_func)
+		match_array = rl_completion_matches (text, generator_func);
+
+	return match_array;
 }
 
 NMCResultCode