New example program

* Makefile.am configure.in examples/hellolibvirt/Makefile.am
  examples/hellolibvirt/hellolibvirt.c: new trivial example program
  by David Allan
Daniel

ChangeLog

+Thu Feb 26 17:13:09 CET 2009 Daniel Veillard <veillard@redhat.com>
+
+	* Makefile.am configure.in examples/hellolibvirt/Makefile.am
+	  examples/hellolibvirt/hellolibvirt.c: new trivial example program
+	  by David Allan
+
 Thu Feb 26 16:05:04 CET 2009 Daniel Veillard <veillard@redhat.com>
 
 	* src/remote_internal.c: fix autostart of session daemon, patch

Makefile.am

@@ -4,7 +4,7 @@ LCOV = lcov
 GENHTML = genhtml
 
 SUBDIRS = gnulib/lib include src qemud proxy docs gnulib/tests \
-  python tests po examples/domain-events/events-c
+  python tests po examples/domain-events/events-c examples/hellolibvirt
 
 ACLOCAL_AMFLAGS = -I m4 -I gnulib/m4
 

configure.in

@@ -1285,7 +1285,8 @@ AC_OUTPUT(Makefile src/Makefile include/Makefile docs/Makefile \
           tests/xmconfigdata/Makefile \
           tests/xencapsdata/Makefile \
           tests/confdata/Makefile \
-          examples/domain-events/events-c/Makefile)
+          examples/domain-events/events-c/Makefile \
+          examples/hellolibvirt/Makefile)
 
 AC_MSG_NOTICE([])
 AC_MSG_NOTICE([Configuration summary])

examples/hellolibvirt/Makefile.am

+INCLUDES = -I@top_srcdir@/include
+noinst_PROGRAMS = hellolibvirt
+hellolibvirt_CFLAGS = $(WARN_CFLAGS)
+hellolibvirt_SOURCES = hellolibvirt.c
+hellolibvirt_LDADD = @top_builddir@/src/libvirt.la

examples/hellolibvirt/hellolibvirt.c

+/* This file contains trivial example code to connect to the running
+ * hypervisor and gather a few bits of information.  */
+
+#include <config.h>
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <libvirt/libvirt.h>
+#include <libvirt/virterror.h>
+
+static void
+showError(virConnectPtr conn)
+{
+    int ret;
+    virErrorPtr err;
+
+    err = malloc(sizeof(*err));
+    if (NULL == err) {
+        printf("Could not allocate memory for error data\n");
+        goto out;
+    }
+
+    ret = virConnCopyLastError(conn, err);
+
+    switch (ret) {
+    case 0:
+        printf("No error found\n");
+        break;
+
+    case -1:
+        printf("Parameter error when attempting to get last error\n");
+        break;
+
+    default:
+        printf("libvirt reported: \"%s\"\n", err->message);
+        break;
+    }
+
+    virResetError(err);
+    free(err);
+
+out:
+    return;
+}
+
+
+static int
+showHypervisorInfo(virConnectPtr conn)
+{
+    int ret = 0;
+    unsigned long hvVer, major, minor, release;
+    const char *hvType;
+
+    /* virConnectGetType returns a pointer to a static string, so no
+     * allocation or freeing is necessary; it is possible for the call
+     * to fail if, for example, there is no connection to a
+     * hypervisor, so check what it returns. */
+    hvType = virConnectGetType(conn);
+    if (NULL == hvType) {
+        ret = 1;
+        printf("Failed to get hypervisor type\n");
+        showError(conn);
+        goto out;
+    }
+
+    if (0 != virConnectGetVersion(conn, &hvVer)) {
+        ret = 1;
+        printf("Failed to get hypervisor version\n");
+        showError(conn);
+        goto out;
+    }
+
+    major = hvVer / 1000000;
+    hvVer %= 1000000;
+    minor = hvVer / 1000;
+    release = hvVer % 1000;
+
+    printf("Hypervisor: \"%s\" version: %lu.%lu.%lu\n",
+           hvType,
+           major,
+           minor,
+           release);
+
+out:
+    return ret;
+}
+
+
+static int
+showDomains(virConnectPtr conn)
+{
+    int ret = 0, i, numNames, numInactiveDomains, numActiveDomains;
+    char **nameList = NULL;
+
+    numActiveDomains = virConnectNumOfDomains(conn);
+    if (-1 == numActiveDomains) {
+        ret = 1;
+        printf("Failed to get number of active domains\n");
+        showError(conn);
+        goto out;
+    }
+
+    numInactiveDomains = virConnectNumOfDefinedDomains(conn);
+    if (-1 == numInactiveDomains) {
+        ret = 1;
+        printf("Failed to get number of inactive domains\n");
+        showError(conn);
+        goto out;
+    }
+
+    printf("There are %d active and %d inactive domains\n",
+           numActiveDomains, numInactiveDomains);
+
+    nameList = malloc(sizeof(*nameList) * numInactiveDomains);
+
+    if (NULL == nameList) {
+        ret = 1;
+        printf("Could not allocate memory for list of inactive domains\n");
+        goto out;
+    }
+
+    numNames = virConnectListDefinedDomains(conn,
+                                            nameList,
+                                            numInactiveDomains);
+
+    if (-1 == numNames) {
+        ret = 1;
+        printf("Could not get list of defined domains from hypervisor\n");
+        showError(conn);
+        goto out;
+    }
+
+    if (numNames > 0) {
+        printf("Inactive domains:\n");
+    }
+
+    for (i = 0 ; i < numNames ; i++) {
+        printf("  %s\n", *(nameList + i));
+        /* The API documentation doesn't say so, but the names
+         * returned by virConnectListDefinedDomains are strdup'd and
+         * must be freed here.  */
+        free(*(nameList + i));
+    }
+
+out:
+    free(nameList);
+    return ret;
+}
+
+
+int
+main(int argc, char *argv[])
+{
+    int ret = 0;
+    virConnectPtr conn;
+    char *uri;
+
+    printf("Attempting to connect to hypervisor\n");
+
+    uri = (argc > 0 ? argv[1] : NULL);
+
+    /* virConnectOpenAuth is called here with all default parameters,
+     * except, possibly, the URI of the hypervisor. */
+    conn = virConnectOpenAuth(uri, virConnectAuthPtrDefault, 0);
+
+    if (NULL == conn) {
+        ret = 1;
+        printf("No connection to hypervisor\n");
+        showError(conn);
+        goto out;
+    }
+
+    uri = virConnectGetURI(conn);
+    if (NULL == uri) {
+        ret = 1;
+        printf("Failed to get URI for hypervisor connection\n");
+        showError(conn);
+        goto disconnect;
+    }
+
+    printf("Connected to hypervisor at \"%s\"\n", uri);
+    free(uri);
+
+    if (0 != showHypervisorInfo(conn)) {
+        ret = 1;
+        goto disconnect;
+    }
+
+    if (0 != showDomains(conn)) {
+        ret = 1;
+        goto disconnect;
+    }
+
+disconnect:
+    if (0 != virConnectClose(conn)) {
+        printf("Failed to disconnect from hypervisor\n");
+        showError(conn);
+        ret = 1;
+    } else {
+        printf("Disconnected from hypervisor\n");
+    }
+
+out:
+    return ret;
+}