admin: Add an example demonstrating how to use the logging APIs

Provide a simple C example demonstrating the use of both query APIs as
well as setter APIs.
Signed-off-by: NErik Skultety <eskultet@redhat.com>

.gitignore

@@ -79,6 +79,7 @@
 /examples/admin/client_limits
 /examples/admin/list_clients
 /examples/admin/list_servers
+/examples/admin/logging
 /examples/admin/threadpool_params
 /examples/object-events/event-test
 /examples/dominfo/info1

examples/Makefile.am

@@ -43,7 +43,7 @@ noinst_PROGRAMS=dominfo/info1 dommigrate/dommigrate domsuspend/suspend \
 	domtop/domtop hellolibvirt/hellolibvirt object-events/event-test \
 	openauth/openauth rename/rename admin/list_servers admin/list_clients \
 	admin/threadpool_params admin/client_limits admin/client_info \
-	admin/client_close
+	admin/client_close admin/logging
 
 dominfo_info1_SOURCES = dominfo/info1.c
 dommigrate_dommigrate_SOURCES = dommigrate/dommigrate.c
@@ -65,6 +65,7 @@ admin_threadpool_params_SOURCES = admin/threadpool_params.c
 admin_client_limits_SOURCES = admin/client_limits.c
 admin_client_info_SOURCES = admin/client_info.c
 admin_client_close_SOURCES = admin/client_close.c
+admin_logging_SOURCES = admin/logging.c
 
 if WITH_APPARMOR_PROFILES
 apparmordir = $(sysconfdir)/apparmor.d/

examples/admin/logging.c

+#include<stdio.h>
+#include<stdlib.h>
+#include<stdbool.h>
+
+#include "config.h"
+#include<unistd.h>
+#include<libvirt/libvirt-admin.h>
+#include<libvirt/virterror.h>
+
+static void printHelp(const char *argv0)
+{
+    fprintf(stderr,
+            ("Usage:\n"
+              "  %s [options]\n"
+              "\n"
+              "Options:\n"
+              "  -h          Print this message.\n"
+              "  -o [string] Specify new log outputs.\n"
+              "  -f [string] Specify new log filters.\n"
+              "\n"),
+            argv0);
+}
+
+int main(int argc, char **argv)
+{
+    int ret, c;
+    virAdmConnectPtr conn = NULL;
+    char *get_outputs = NULL;
+    char *get_filters = NULL;
+    const char *set_outputs = NULL;
+    const char *set_filters = NULL;
+
+    ret = c = -1;
+    opterr = 0;
+
+    while ((c = getopt(argc, argv, ":hpo:f:")) > 0) {
+        switch (c) {
+        case 'h':
+            printHelp(argv[0]);
+            exit(EXIT_SUCCESS);
+        case 'o':
+            set_outputs = optarg;
+            break;
+        case 'f':
+            set_filters = optarg;
+            break;
+        case ':':
+            fprintf(stderr, "Missing argument for option -%c\n", optopt);
+            exit(EXIT_FAILURE);
+        case '?':
+            fprintf(stderr, "Unrecognized option '-%c'\n", optopt);
+            exit(EXIT_FAILURE);
+        }
+    }
+
+    /* first, open a connection to the daemon */
+    if (!(conn = virAdmConnectOpen(NULL, 0)))
+        goto cleanup;
+
+    /* get the currently defined log outputs and filters */
+    if (virAdmConnectGetLoggingOutputs(conn, &get_outputs, 0) < 0 ||
+        virAdmConnectGetLoggingFilters(conn, &get_filters, 0) < 0)
+        goto cleanup;
+
+    fprintf(stdout,
+            "Current settings:\n"
+            " outputs: %s\n"
+            " filters: %s\n"
+            "\n",
+            get_outputs, get_filters ? get_filters : "None");
+
+    free(get_outputs);
+    free(get_filters);
+
+    /* no arguments were provided */
+    if (argc == 1) {
+        ret = 0;
+        goto cleanup;
+    }
+
+    /* now, try to change the redefine the current log output and filters */
+    if (virAdmConnectSetLoggingOutputs(conn, set_outputs, 0) < 0)
+        goto cleanup;
+
+    if (virAdmConnectSetLoggingFilters(conn, set_filters, 0) < 0)
+        goto cleanup;
+
+    /* get the currently defined log outputs and filters */
+    if (virAdmConnectGetLoggingOutputs(conn, &get_outputs, 0) < 0 ||
+        virAdmConnectGetLoggingFilters(conn, &get_filters, 0) < 0)
+        goto cleanup;
+
+    fprintf(stdout,
+            "New settings:\n"
+            " outputs: %s\n"
+            " filters: %s\n"
+            "\n",
+            get_outputs ? get_outputs : "Default",
+            get_filters ? get_filters : "None");
+
+    free(get_outputs);
+    free(get_filters);
+
+    ret = 0;
+ cleanup:
+    virAdmConnectClose(conn);
+    return ret;
+}