c++检查程序是否已经启动

方式一：

实例代码：

#include 
#include 
#include 
#include 
#include 
#include 
#include 
using namespace std;

long getrunpid(const char* pidfile)
{
	long pid;
	FILE *fp = fopen(pidfile, "r+");
	if(fp == NULL)
	{
		perror("open file error");
		return -1L;
	}
	if(fp && fscanf(fp,"%lu", &pid)==1 && pid >0)
	{
		if(kill((pid_t)pid,0)>=0 || errno != ESRCH)
		{
			fclose(fp);
			return pid;			
		}
	}
	fclose(fp);
	return -1L;
}

void setrunpid(const char *pidfile)
{
	long pid = getrunpid(pidfile);
	if(pid > 0)
	{
		cout << "the program is already running\n";
		return;
	}
	pid = (long)getpid();
	FILE *fp = fopen(pidfile, "w");
	if(fp)
	{
		fprintf(fp, "%lu", pid);
		fclose(fp);
	}
}

int main(int argc, char *argv[])
{
    const char* pidfile = "./test.pid";
	setrunpid(pidfile);
	while(1);
    return 0;
}

实例二：

extern int checkeprogram(const char* shellstr, const char* str)
{
	int live = 0;
	char line[120];
	FILE* fp = popen(shellstr, "r");
	if(fp == NULL)
	{
		cout << "popen error\n";
		return -1;
	}
	while(!feof(fp)){
		memset(line, 0, sizeof(line));
		fgets(line, sizeof(line), fp);
		if(strstr(line, str) != NULL){
			live++;
			if(live == 2){
				break;
			}
		}
	}
	pclose(fp);
	if(live == 2){
		return 1;
	}
	return 0;
}

调用方法如下：

 int ret = checkeprogram("ps -ef| grep test_server", "./test_server");
	if(ret == 1)
	{
		cout << "the program already exist\n";
		return -1;
	}