linux下如何获得系统信息,比如cpu占用率

[xindao_wang]

RT
谢谢

[afeicome]

cat 查看/proc 下的信息吧
你自己找找
有很多的教程的

[YanDong_8212]

TOP命令可以

[fierygnu]

在本论坛搜CPU。

[lilywon]

du,disk use

[fytzzh]

1，可以查看/proc文件
2，通过命令: top sar vmstat

[Mybox]

#define SET_IF_DESIRED(x,y) if(x) *(x) = (y)
#define _ULL unsigned long long

int FiveCpuNumbers(_ULL *uret,_ULL *nret,_ULL *sret,_ULL *iret,_ULL *iowait)
{
static _ULL u = 0, m = 0, s = 0, i = 0, iw = 0;
_ULL user_j, nice_j, sys_j, idle_j, iowait_j = 0;
FILE *fp;
size_t byte_read;
char buffer[100];

fp = fopen("/proc/stat", "r");
byte_read = fread(buffer, 1, sizeof(buffer)-1, fp);
fclose(fp);

if (byte_read==0 || byte_read==sizeof(buffer))
return -1;
buffer[byte_read] = '\0';

sscanf(buffer, "cpu %Lu %Lu %Lu %Lu %Lu", &user_j, &nice_j, &sys_j, &idle_j, &iowait_j);
SET_IF_DESIRED(uret, user_j - u);
SET_IF_DESIRED(nret, nice_j - m);
SET_IF_DESIRED(sret, sys_j - s);
/* Idle can go backwards one tick due to kernel calculation issues */
SET_IF_DESIRED(iret, (idle_j > i) ? (idle_j - i) : 0);
SET_IF_DESIRED(iowait, iowait_j - iw);
u = user_j;
m = nice_j;
s = sys_j;
i = idle_j;
iw = iowait_j;
//printf("cpu %Lu %Lu %Lu %Lu %Lu \n",user_j,nice_j,sys_j,idle_j,iowait_j);

return 0;
}

/*
* get the cpu usage
*/
int ReadCpuInfo(float &fCpuUsage)
{
float cpu_usage;
_ULL user_j, nice_j, sys_j, idle_j, iowait_j = 0;

if(FiveCpuNumbers(&user_j, &nice_j, &sys_j, &idle_j, &iowait_j)!=0)
return -1;
usleep(500000);
if(FiveCpuNumbers(&user_j, &nice_j, &sys_j, &idle_j, &iowait_j)!=0)
return -1;
//usleep(500000);
//if(FiveCpuNumbers(&user_j, &nice_j, &sys_j, &idle_j, &iowait_j)!=0)
//return -1;

cpu_usage = (idle_j * 100.0) / (user_j + nice_j + sys_j + idle_j + iowait_j);

if (cpu_usage>100)
cpu_usage = 100.0;

/* change to useage */
cpu_usage = 100.0 - (cpu_usage);
fCpuUsage = cpu_usage;
printf("### CPU Usage : %0.3f %%\n", cpu_usage);
return 0;
}
#undef _ULL

[genphen]

什么叫抢占率阿？

[jjduan185]

top源代码里面machine目录下的m_linux.c里面有一个get_system_info的方法，可以获得内存，CPU，经过适当的的加工后，可以获得网络流量和磁盘空间，另外top还可一个获得进程列表

[jjduan185]

typedef struct ProcInfo
{
char name[MAX_PROC_NAME];/*process name*/
int PID; /*process id*/
int PPID; /*parent process id*/
int status; /* sleeping or running*/
struct ProcInfo * Next; /*pointer to next process struct*/
}* ProcList;
typedef struct netCards
{
char name[MAX_NET_CARD_NAME];/*net card name*/
int ByteRcv; /*bytes received*/
int ByteSnd; /*bytes sent*/
}* netCardList;
struct eCop_SM_Object
{
char OsName[MAX_OS_NAME];/*do not alarm*/
int CPU_Percent[MAX_CPUS];/*for example 34 means 0.34%*/
int DiskAvail; /*available disk*/
int MemUsed; /*memory used*/
/*including sending bytes and receiving bytes*/
struct netCards netCard[MAX_NET_CARDS];
struct ProcInfo * PrList;
/*
evaluate the time to it when sampling, if
it is -1,we consider it an invalid object
*/
long TimeStamp;
};
/*get os information and store it in a struct*/
int sample(struct eCop_SM_Object * obj);

[xindao_wang]

解决了，谢谢各位了

[hong106525654]

高手解释一下if(x) *(x) = (y)这是什么意思啊

[fierygnu]

if (x)
*(x) = (y)
x是指针，y是值。