Linux环境资源限制例程

 1 #include <sys/types.h>
 2 #include <sys/resource.h>
 3 #include <sys/time.h>
 4 #include <unistd.h>
 5 #include <stdio.h>
 6 #include <math.h>
 7 
 8 void work()
 9 {
10     FILE *f;
11     int i;
12     double x=4.5;
13     f=tmpfile();
14     for(i=0;i<10000;i++);
15     {
16         fprintf(f,"Do some output\n");//将一个字符串写入临时文件10000
17         if(ferror(f))
18         {
19             fprintf(stderr,"Error writing to temporary file\n");
20             exit(1);
21         }
22     }//完成
23     for (i=0;i<1000000;i++)
24         x=log(x*x+3.21);//做一些算术运算
25 }
26 
27 int main()
28 {
29     struct rusage r_usage;
30     struct rlimit r_limit;
31     int priority;
32     
33     work();
34     getrusage(RUSAGE_SELF, &r_usage);//第一个参数代表仅返回当前程序的使用信息，保存在第二个参数中
35     
36     printf("CPU usage: User=%ld.%06ld,System=%ld.%06ld\n",
37     r_usage.ru_utime.tv_sec,r_usage.ru_utime.tv_usec,
38     r_usage.ru_stime.tv_sec,r_usage.ru_stime.tv_usec);//打印出cpu消耗
39     
40     priority=getpriority(PRIO_PROCESS, getpid());
41     printf("Current priority = %d\n", priority);//获取当前优先级
42     
43     getrlimit(RLIMIT_FSIZE,&r_limit);//获取当前文件限制
44     printf("Current FSIZE limit: soft=%ld, hard=%ld\n",r_limit.rlim_cur,r_limit.rlim_max);
45     
46     r_limit.rlim_cur=2048;
47     r_limit.rlim_max=4096;
48     printf("Setting a 2k file size limit\n");
49     setrlimit(RLIMIT_FSIZE,&r_limit);
50     
51     work();
52     exit(0);
53 }

 1 jason@t61:~/c_program$ ./limits 
 2 CPU usage: User=0.056000,System=0.000000
 3 Current priority = 0
 4 Current FSIZE limit: soft=-1, hard=-1
 5 Setting a 2k file size limit
 6 jason@t61:~/c_program$ ulimit 
 7 unlimited
 8 jason@t61:~/c_program$ nice ./limits 
 9 CPU usage: User=0.060000,System=0.000000
10 Current priority = 10
11 Current FSIZE limit: soft=-1, hard=-1
12 Setting a 2k file size limit