Linux C++中獲取指定pid、tid的CPU與內存佔用信息

 使用的是ps命令+popen函數，直接上代碼

 

#include<iostream>
using namespace std;
#define _LINE_LENGTH 300


bool GetCpuMem(float &cpu,size_t &mem, int pid,int tid = -1)
{
    bool ret = false;
    char cmdline[100];
    sprintf(cmdline, "ps -o %%cpu,rss,%%mem,pid,tid -mp %d", pid);
    FILE *file;
    file = popen(cmdline, "r");
    if (file == NULL)
    {
        printf("file == NULL\n");
        return false;
    }

    char line[_LINE_LENGTH];
    float l_cpuPrec=0;
    int l_mem=0;
    float l_memPrec=0;
    int l_pid=0;
    int l_tid=0;
    if (fgets(line, _LINE_LENGTH, file) != NULL)
    {
    //  printf("1st line:%s",line);
        if (fgets(line, _LINE_LENGTH, file) != NULL)
        {
    //      printf("2nd line:%s",line);
            sscanf( line, "%f %d %f %d -", &l_cpuPrec, &l_mem, &l_memPrec, &l_pid );
            cpu = l_cpuPrec;
            mem = l_mem/1024;
            if( tid == -1 )
                ret = true;
            else
            {
                while( fgets(line, _LINE_LENGTH, file) != NULL )
                {
                    sscanf( line, "%f - - - %d", &l_cpuPrec, &l_tid );
    //              printf("other line:%s",line);
    //              cout<<l_cpuPrec<<'\t'<<l_tid<<endl;
                    if( l_tid == tid )
                    {
                        printf("cpuVal is tid:%d\n",tid);
                        cpu = l_cpuPrec;
                        ret = true;
                        break;
                    }
                }
                if( l_tid != tid )
                    printf("TID not exist\n");
            }
        }
        else
            printf("PID not exist\n");
    }
    else
        printf("Command or Parameter wrong\n");
    pclose(file);
    return ret;
}

int main(int argc, char** argv)
{
    float cpu=0;
    size_t mem=0;
    int pid=0;
    int tid=-1;
    if( argc > 1 )
        pid = atoi(argv[1]);
    else
        pid = getpid();
    if( argc > 2 )
        tid = atoi(argv[2]);
    while(1)
    {
        if( GetCpuMem( cpu, mem, pid, tid ) )
        {
            printf("%%CPU:%.1f\tMEM:%dMB\n", cpu, mem);
        }
        else
            printf("return false\n");
        break;
        sleep(5);
    }

    return 0;
}

編譯：g++ GetInfo.cpp -o GetInfo -g

測試命令：

./GetInfo pid

顯示pid進程cpu及內存信息

./GetInfo pid tid

顯示pid進程的內存佔用和其中tid線程的cpu佔用信息

./GetInfo 什麼參數都不輸入顯示本進程cpu及內存信息（有點雞肋）