检测进程是否存在

//检查指定进程是否存在
int detect_process(const char * process_name)
{
int n = -1;

FILE *strm;
char buf[128];

sprintf(buf,"ps -e | grep -c %s", process_name);

if((strm=popen(buf, "r")) != NULL)
{
if(fgets(buf, sizeof(buf), strm) != NULL)
{
n = atoi(buf);
if(n > 2)
{
return n;
}
}
}
else
{
return -1;
}

pclose(strm);

return 0;
}