src/mech: add some basic 'show' commands

- Example of optional args (show log [FILE])
 - Example of dynamic expansion
 - Example of how to re-enable signals for external commands
 - Example of hidden commands
 - Add basic 'help' command for the current level

Signed-off-by: Joachim Wiberg <troglobit@gmail.com>

src/mech/src/core/core-cli.c

@@ -1,3 +1,4 @@
+#include <glob.h>
 #include <stdio.h>
 
 #include <cligen/cligen.h>
@@ -5,9 +6,85 @@
 #include <clixon/clixon_cli.h>
 #include <clixon/cli_generate.h>
 
-int cli_sysinfo(clicon_handle h, cvec *cvv, cvec *argv)
+#define _PATH_LOG "/var/log/"
+
+/* Not exported in the common Clixon API, needed to run external commands */
+void cli_signal_block(clicon_handle h);
+void cli_signal_unblock(clicon_handle h);
+
+static int exec(clicon_handle h, char *cmd)
 {
-	printf("System Information: Infix\n");
+	int rc;
+
+	cli_signal_unblock(h);
+	rc = system(cmd);
+	cli_signal_block(h);
+
+	return rc;
+}
+
+int cli_exec_shell(clicon_handle h, cvec *cvv, cvec *argv)
+{
+	return exec(h, "$SHELL -l");
+}
+
+int cli_exec_show(clicon_handle h, cvec *cvv, cvec *argv)
+{
+	char cmd[256];
+	int pos = 0;
+	int i;
+
+	for (i = 0; i < cvec_len(cvv); i++)
+		pos += snprintf(&cmd[pos], sizeof(cmd) - pos, "%s ",
+				cv_string_get(cvec_i(cvv, i)));
+
+	return exec(h, cmd);
+}
+
+int cli_exec_log(clicon_handle h, cvec *cvv, cvec *argv)
+{
+	char cmd[128], arg[32];
+	cg_var *cv;
+
+	/* cvv[0] is the whole command, e.g. 'show log btmp' */
+	if (!strncmp("follow", cv_string_get(cvec_i(cvv, 0)), 6))
+		snprintf(cmd, sizeof(cmd), "tail -F ");
+	else
+		snprintf(cmd, sizeof(cmd), "cat ");
+
+	cv = cvec_find(cvv, "fn");
+	if (cv) {
+		snprintf(arg, sizeof(arg), _PATH_LOG "%s", cv_string_get(cv));
+		strcat(cmd, arg);
+	} else
+		strcat(cmd, _PATH_LOG "syslog");
+
+	return exec(h, cmd);
+}
+
+int logfiles(cligen_handle h, char *fn_str, cvec *cvv, cg_var *argv,
+	     cvec *commands, cvec *helptexts)
+{
+	glob_t gl;
+	size_t i;
+	int rc;
+
+	rc = glob(_PATH_LOG "*", 0, NULL, &gl);
+	if (rc && rc != GLOB_NOMATCH)
+		return 0;
+
+	for (i = 0; i < gl.gl_pathc; i++) {
+		char *fn;
+
+		fn = rindex(gl.gl_pathv[i], '/');
+		if (fn)
+			fn++;
+		else
+			fn = gl.gl_pathv[i];
+		cvec_add_string(commands, NULL, fn);
+	}
+	globfree(&gl);
+
 	return 0;
 }
 

src/mech/src/core/core-cli.cli

@@ -32,8 +32,23 @@ copy("Copy and create a new object") {
     }
 }
 
+follow("Continuously monitor a log file, default syslog"),   cli_exec_log(); {
+    <fn:string logfiles()>(""),                              cli_exec_log();
+}
+
+help("Show help"), cli_help();
+
 show("Show various system state and configuration") {
-	system-information("System information"), cli_sysinfo();
+	system-information("System information"),            cli_exec_show();
+	fdb("Show forwarding database (unicast)"),           cli_exec_show();
+	mdb("Show multicast forwarding database (unicast)"), cli_exec_show();
+	ports("Show ports available for bridging"),          cli_exec_show();
+	vlans("Show port groups in bridge"),                 cli_exec_show();
+	ifaces("Show interfaces and their addresses"),       cli_exec_show();
+	log("Show latest syslog entries"),                   cli_exec_log(); {
+		<fn:string logfiles()>(""),                  cli_exec_log();
+	}
+	version("Show operating system version"),            cli_exec_show();
 
 	auto("Show expand x") {
 		xml @datamodelshow, cli_show_auto("candidate", "xml", true, false, "report-all");
@@ -72,3 +87,6 @@ show("Show various system state and configuration") {
 		}
 	}
 }
+
+# Hidden shell command, after 'show' command to avoid any possible completion problems
+shell("Start domain shell"), hide, cli_exec_shell();