基于C语言libvirt API简单小程序

libvirt API简单小程序

1、程序代码如下

#include<stdio.h>
#include<libvirt/libvirt.h>

int getDomainInfo(int id) {
	virConnectPtr conn = NULL;
	virDomainPtr dom = NULL;
	virDomainInfo info;

	conn = virConnectOpenReadOnly(NULL);
	if (conn == NULL) {
		fprintf(stderr, "Failed to connect to hypervisor\n");
		return 1;
	}
	dom = virDomainLookupByID(conn, id);
	if (dom == NULL) {
		fprintf(stderr, "Failed to find Domain %d\n", id);
		virConnectClose(conn);
		return 1;
	}
	if (virDomainGetInfo(dom, &info) < 0) {
		fprintf(stderr, "Failed to get information for Domain %d\n", id);
		virDomainFree(dom);
		virConnectClose(conn);
		return 1;
	}
	printf("Domain ID: %d\n", id);
	printf("    vCPUs: %d\n", info.nrVirtCpu);
	printf("    maxMem: %d KB\n", info.maxMem);
	printf("    memory: %d KB\n", info.memory);

	if (dom != NULL){
		virDomainFree(dom);
	}
	if (conn != NULL){
		virConnectClose(conn);
	}
	return 0;
}
int main(int argc, char **argv)
{
	int dom_id = 3;
	printf("-----Get domain info by ID via libvirt C API -----\n");
	getDomainInfo(dom_id);
	return 0;
}

2、程序编译并运行，运行结果如图1所示

gcc dominfo.c -o dominfo -lvirt
./dominfo

　　-lvirt指定程序链接时的共享库，在本文实验环境中依赖的共享库文件路径为/usr/lib/libvirt.so

图 1

将运行结果和virsh的运行的结果相比较，virsh的结果如图2所示

图 2