count_nic.c

在Linux操作系统下实现的软件交换技术

#include<stdio.h>
#include<stdlib.h>

#define P printf

//------------------------------------------------------------------------------
//Count the number of NICs on this Switch
//------------------------------------------------------------------------------

int count_nics()
{

	FILE * f_c;
	int count;

//Count the number of device in the system

if(system("/sbin/ifconfig -a | grep \"^eth\" |wc -l  > count_NIC_file")==-1)
{
	P("Error when check those files!!\n");
	P("Can not continue, please report this bug to [e-mail].\n");
	P("Can not continue, please report this bug to [e-mail].\n");
exit(1);
}
//P("Done.\n");
f_c=fopen("count_NIC_file", "r");
if(!f_c)
{
	P("Can't generate temp file in local disk.\n");
	P("Please report this bug to [e-mail].\n");
	P("Can not continue.\n");
	exit(1);
}
count=-1;
fscanf(f_c, "%d", &count);

if(count<2)
{
	P("The switch must have at least 2 NICs.\n");
	P("Can not continue..STOP!\n");
	exit(0);
}

fclose(f_c);

if(system("rm -f count_NIC_file")==-1)
{
P("Error!\n");
P("Cannot continue, please report to [e-mail]\n");
exit(1);
}
return count;
}