linux 系统操作

1.取一个进程的内存，cpu等信息

ps -p 进程ID -o pid,pcpu,vsz,thcount,sz|grep -v CPU

2.获取CPU的个数：

cat /proc/cpuinfo |grep processor|wc -l

3.获取某一个进程的句柄

int getPrFdNum(const string& sPid, int& fdNum)
{
	fdNum = 0;            
	if (sPid.empty())
	{
		ErrorOut("getPrFdNum: failed ,pid is null!");
		return -1;
	}
	string sPath = string("/proc/") + sPid + string("/fd");

	ACE_Dirent_Selector sds;
	int iStatus = sds.open(sPath.c_str(),NULL, NULL);
	if (iStatus <= 0)
	{
		ErrorOut("getPrFdNum: failed to get %s 's handls!",sPath.c_str());
		return -1;
	}

	if(sds.length() >= 2) // Subtract . and ..
	{
		fdNum = sds.length()-2;
	}
	else
	{
		ErrorOut("getPrFdNum: %s 's handls count is less than 2!", sPath.c_str());
	}

	sds.close(); // Notice: If sds.close() is missed, memory leak will occur!

	return 0;
}

4.用c++取程序的虚拟内存

long getVMemoryForNX()
{
    long vsz = 0;
#ifndef WIN32
    pid_t mypid = getpid();

    std::stringstream ss;
    ss << mypid;

    std::string pid = ss.str();
    printf("pid=%s\n", pid.c_str());

    //long useMemKB = 0;
    std::string strcmd;
    strcmd += "ps -o vsz -p ";
    strcmd +=  pid;
    strcmd += "|/usr/bin/grep -v VSZ";
    FILE *pfile = popen(strcmd.c_str(), "r");
    if (NULL == pfile)
    {
        printf("LinuxPrStat::getProcInfo run %s failure!", strcmd.c_str());
    }
    else
    {
        while( !feof(pfile) )
        {
            char strresult[1024] = {0};
            fread(strresult, 1, 1024, pfile);
            //printf("strsult=%s", strresult);
            if (strlen(strresult))
            {
                vsz = atol(strresult);
            }                               
        }
        pclose(pfile);
    }
#endif

    return vsz;
}