Linux C++ 获取某一进程的CPU占用率以及内存占用情况

#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 14typedef 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 timeunsigned long stime;  //kernel timeunsigned 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;}