Linux环境资源限制例程

#include <sys/types.h>
#include <sys/resource.h>
#include <sys/time.h>
#include <unistd.h>
#include <stdio.h>
#include <math.h>

void work()
{
    FILE *f;
    int i;
    double x=4.5;
    f=tmpfile();
    for(i=0;i<10000;i++);
    {
        fprintf(f,"Do some output
");//将一个字符串写入临时文件10000
        if(ferror(f))
        {
            fprintf(stderr,"Error writing to temporary file
");
            exit(1);
        }
    }//完成
    for (i=0;i<1000000;i++)
        x=log(x*x+3.21);//做一些算术运算
}

int main()
{
    struct rusage r_usage;
    struct rlimit r_limit;
    int priority;
    
    work();
    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
    
    printf("CPU usage: User=%ld.%06ld,System=%ld.%06ld
",
    r_usage.ru_utime.tv_sec,r_usage.ru_utime.tv_usec,
    r_usage.ru_stime.tv_sec,r_usage.ru_stime.tv_usec);//打印出cpu消耗
    
    priority=getpriority(PRIO_PROCESS, getpid());
    printf("Current priority = %d
", priority);//获取当前优先级
    
    getrlimit(RLIMIT_FSIZE,&r_limit);//获取当前文件限制
    printf("Current FSIZE limit: soft=%ld, hard=%ld
",r_limit.rlim_cur,r_limit.rlim_max);
    
    r_limit.rlim_cur=2048;
    r_limit.rlim_max=4096;
    printf("Setting a 2k file size limit
");
    setrlimit(RLIMIT_FSIZE,&r_limit);
    
    work();
    exit(0);
}

运行效果

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