IPV4 转 整型数，与 整形数 转 IPV4

#include <stdio.h>
#include <string.h>

char g_buf[100] = {0};

//IPV4 转 整型
in_addr_t ip2i(const char* strptr)  //in_addr_i 可以看作是int
{
	char * p = NULL;
	char * q = NULL;
	int a[4] = {0};
	int i = 0;
	in_addr_t addr = 0;
	char buf[100] = {0};
	strcpy(buf,strptr);
	p = strtok(buf,".");
	a[i++] = atoi(p);
        while((q = strtok(NULL, ".")))
	{
		a[i++] = atoi(q);
	}
/*
	for(i = 0; i < 4; i++)
	{
		printf("%d ",a[i]);
	}
*/
    addr = a[3] |(a[2]<<8)|(a[1]<<16)|(a[0]<<24);
	return addr;
}
//整型 转 IPV4
char* i2ip(in_addr_t i) //int i
{
	
	sprintf(g_buf+strlen(g_buf),"%d.",(i>>24)&0xff);
	sprintf(g_buf+strlen(g_buf),"%d.",(i>>16)&0xff);
	sprintf(g_buf+strlen(g_buf),"%d.",(i>>8)&0xff);
	sprintf(g_buf+strlen(g_buf),"%d", i&0xff);
	return g_buf;
}

int main()
{
	printf("0x%08X\n",ip2i("192.168.0.55"));
	printf("%s\n",i2ip(0xc0a80037));
	
    return 0;
}