测试kernel.pid_max值

# sysctl kernel.pid_max
kernel.pid_max = 32768
# sysctl -w kernel.pid_max=500
kernel.pid_max = 500  

#include <unistd.h>
#include <stdio.h>
int main ()
{
    pid_t fpid; //fpid表示fork函数返回的值
    int count=0;
    while(1) {
        fpid=fork();
        if (fpid < 0) {
            printf("error in fork!\n");
            break;
        }
        else if (fpid == 0) {
            count++;
        } else {
        sleep(100);
        return 0;
        }
    }
    printf("count is %d\n", count);
    return 0;
}

# gcc test.c; ./a.out
error in fork!
count is 172