linux c 获取进程 cpu占用率内存占用情况-蒲公英云

linux c 获取进程 cpu占用率内存占用情况

实例如下：

#include <stdio.h>
#include <unistd.h>
#include <sys/time.h>
#include <string.h>
#include <stdlib.h>
#define VMRSS_LINE 17
#define VMSIZE_LINE 13
#define PROCESS_ITEM 14
typedef struct {
    unsigned long user;
    unsigned long nice;
    unsigned long system;
    unsigned long idle;
}Total_Cpu_Occupy_t;
typedef struct {
    unsigned int pid;
    unsigned long utime;  //user time
    unsigned long stime;  //kernel time
    unsigned long cutime; //all user time
        unsigned long cstime; //all dead time
}Proc_Cpu_Occupy_t;
//获取第N项开始的指针
const char* get_items(const char*buffer ,unsigned int item){
    const char *p =buffer;
    int len = strlen(buffer);
    int count = 0;
    for (int i=0; i<len;i++){
        if (' ' == *p){
            count ++;
            if(count == item -1){
                p++;
                break;
            }
        }
        p++;
    }
    return p;
}
//获取总的CPU时间
unsigned long get_cpu_total_occupy(){
    FILE *fd;
    char buff[1024]={0};
    Total_Cpu_Occupy_t t;
    fd =fopen("/proc/stat","r");
    if (nullptr == fd){
        return 0;
    }
    fgets(buff,sizeof(buff),fd);
    char name[64]={0};
    sscanf(buff,"%s %ld %ld %ld %ld",name,&t.user,&t.nice,&t.system,&t.idle);
    fclose(fd);
    return (t.user + t.nice + t.system + t.idle);
}
//获取进程的CPU时间
unsigned long get_cpu_proc_occupy(unsigned int pid){
    char file_name[64]={0};
    Proc_Cpu_Occupy_t t;
    FILE *fd;
    char line_buff[1024]={0};
    sprintf(file_name,"/proc/%d/stat",pid);
    fd = fopen(file_name,"r");
    if(nullptr == fd){
        return 0;
    }
    fgets(line_buff,sizeof(line_buff),fd);
    sscanf(line_buff,"%u",&t.pid);
    const char *q =get_items(line_buff,PROCESS_ITEM);
    sscanf(q,"%ld %ld %ld %ld",&t.utime,&t.stime,&t.cutime,&t.cstime);
    fclose(fd);
    return (t.utime + t.stime + t.cutime + t.cstime);
}
//获取CPU占用率
float get_proc_cpu(unsigned int pid){
    unsigned long totalcputime1,totalcputime2;
    unsigned long procputime1,procputime2;
    totalcputime1=get_cpu_total_occupy();
    procputime1=get_cpu_proc_occupy(pid);
    usleep(200000);
    totalcputime2=get_cpu_total_occupy();
    procputime2=get_cpu_proc_occupy(pid);
    float pcpu = 0.0;
    if(0 != totalcputime2-totalcputime1){ 
        pcpu=100.0 * (procputime2-procputime1)/(totalcputime2-totalcputime1);
    }
    return pcpu;
}
//获取进程占用内存
unsigned int get_proc_mem(unsigned int pid){
    char file_name[64]={0};
    FILE *fd;
    char line_buff[512]={0};
    sprintf(file_name,"/proc/%d/status",pid);
    fd =fopen(file_name,"r");
    if(nullptr == fd){
        return 0;
    }
    char name[64];
    int vmrss;
    for (int i=0; i<VMRSS_LINE-1;i++){
        fgets(line_buff,sizeof(line_buff),fd);
    }
    fgets(line_buff,sizeof(line_buff),fd);
    sscanf(line_buff,"%s %d",name,&vmrss);
    fclose(fd);
    return vmrss;
}
//获取进程占用虚拟内存
unsigned int get_proc_virtualmem(unsigned int pid){
    char file_name[64]={0};
    FILE *fd;
    char line_buff[512]={0};
    sprintf(file_name,"/proc/%d/status",pid);
    fd =fopen(file_name,"r");
    if(nullptr == fd){
        return 0;
    }
    char name[64];
    int vmsize;
    for (int i=0; i<VMSIZE_LINE-1;i++){
        fgets(line_buff,sizeof(line_buff),fd);
    }
    fgets(line_buff,sizeof(line_buff),fd);
    sscanf(line_buff,"%s %d",name,&vmsize);
    fclose(fd);
    return vmsize;
}
//进程本身
int get_pid(const char* process_name, const char* user = nullptr)
{
    if(user == nullptr){
        user = getlogin();    
    }
    char cmd[512];
    if (user){
        sprintf(cmd, "pgrep %s -u %s", process_name, user);    
    }
    FILE *pstr = popen(cmd,"r");    
    if(pstr == nullptr){
        return 0;    
    }
    char buff[512];
    ::memset(buff, 0, sizeof(buff));
    if(NULL == fgets(buff, 512, pstr)){
        return 0;
    }
    return atoi(buff);
}
int main(int argc, char *argv[])
{
    if(argc < 2){
        printf("Usage:test <process_name> [user]\n");
        return 1;
    }
    unsigned int pid=0;
    if(argc > 2){
        pid = get_pid(argv[1],argv[2]);
    }
    else{
        pid = get_pid(argv[1]);
    }
    printf("pid=%d\n",pid);
    printf("pcpu=%f\n",get_proc_cpu(pid));
    printf("procmem=%d\n",get_proc_mem(pid));
    printf("virtualmem=%d\n",get_proc_virtualmem(pid));    
    return 0;
}