linux c 获取进程 cpu占用率内存占用情况

╰+攻爆jí腚メ 2021-09-03 07:58 813阅读 0赞

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;
    }