#include 
     
      #include 
      
       int main(){    system("ping 112.24.234.47 -c 4 |grep 'Unreachable' > 1.txt");    FILE* fp = fopen("1.txt","r");    char ch = fgetc(fp);    if(EOF == ch)    {        printf("可以联网\n");    }    else    {        printf("不能上网\n");    }    system("rm -rf 1.txt");    fclose(fp);    return 0;}