Bitcoin price trend in June 2014
according to the data of coindesk digital currency trading platform, the price of bitcoin once fell below US $6000 in 18 years, which has dropped by 70% compared with the highest value of US $20000 in 2017
"the price movements we are seeing now may seem drastic, but they are quite normal for this market." Etiro's senior market analyst, MATI Greenspan, wrote in an email to CNBC
with the decline of bitcoin, most digital currencies are affected, and other digital currencies are not much better. Most digital currencies are down by more than 10%. But in the long run, the future of digital currency is worth looking forward to.
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <netdb.h>
#include <sys/ioctl.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/ip.h>
#include <netinet/in.h>
#include <netinet/if_ether.h>
#include <netpacket/packet.h>
#include <net/ethernet.h>
#include <net/if.h>
#include <arpa/inet.h>
#include <errno.h>
/* 接收缓冲区大小 */
#define RCV_BUF_SIZE 1024 * 5
/* 接收缓冲区 */
static int g_iRecvBufSize = RCV_BUF_SIZE;
static char g_acRecvBuf[RCV_BUF_SIZE] = {0};
/* 物理网卡接口,需要根据具体情况修改 */
static const char *g_szIfName = "eth1";
/* 以太网帧封装的协议类型 */
static const int g_iEthProId[] = { ETHERTYPE_PUP,
ETHERTYPE_SPRITE,
ETHERTYPE_IP,
ETHERTYPE_ARP,
ETHERTYPE_REVARP,
ETHERTYPE_AT,
ETHERTYPE_AARP,
ETHERTYPE_VLAN,
ETHERTYPE_IPX,
ETHERTYPE_IPV6,
ETHERTYPE_LOOPBACK
};
static const char g_szProName[][24] = {
"none", "xerox pup", "sprite", "ip", "arp",
"rarp", "apple-protocol", "apple-arp",
"802.1q", "ipx", "ipv6", "loopback"
};
/* 输出MAC地址 */
static void ethmp_showMac(const int iType, const char acHWAddr[])
{ int i = 0;
if (0 == iType)
{
printf("SMAC=[");
}
else
{
printf("DMAC=[");
}
for(i = 0; i < ETHER_ADDR_LEN - 1; i++)
{
printf("%02x:", *((unsigned char *)&(acHWAddr[i])));
}
printf("%02x] ", *((unsigned char *)&(acHWAddr[i])));
}
/* 物理网卡混杂模式属性操作 */
static int ethmp_setPromisc(const char *pcIfName, int fd, int iFlags)
{ int iRet = -1;
struct ifreq stIfr;
/* 获取接口属性标志位 */
strcpy(stIfr.ifr_name, pcIfName);
iRet = ioctl(fd, SIOCGIFFLAGS, &stIfr);
if (0 > iRet)
{ perror("[Error]Get Interface Flags");
return -1;
}
if (0 == iFlags)
{ /* 取消混杂模式 */
stIfr.ifr_flags &= ~IFF_PROMISC;
}
else
{ /* 设置为混杂模式 */
stIfr.ifr_flags |= IFF_PROMISC;
}
iRet = ioctl(fd, SIOCSIFFLAGS, &stIfr);
if (0 > iRet)
{ perror("[Error]Set Interface Flags");
return -1;
}
return 0;
}
/* 获取L2帧封装的协议类型 */
static char *ethmp_getProName(const int iProNum)
{ int iIndex = 0;
for(iIndex = 0; iIndex < sizeof(g_iEthProId) / sizeof(g_iEthProId[0]); iIndex++)
{ if (iProNum == g_iEthProId[iIndex])
{
break;
}
}
return (char *)(g_szProName[iIndex + 1]);
}
/* Init L2 Socket */
static int ethmp_initSocket()
{ int iRet = -1;
int fd = -1;
struct ifreq stIf;
struct sockaddr_ll stLocal = {0};
/* 创建SOCKET */
fd = socket(PF_PACKET, SOCK_RAW, htons(ETH_P_ALL));
if (0 > fd)
{ perror("[Error]Initinate L2 raw socket");
return -1;
}
/* 网卡混杂模式设置 */
ethmp_setPromisc(g_szIfName, fd, 1);
/* 设置SOCKET选项 */
iRet = setsockopt(fd, SOL_SOCKET, SO_RCVBUF, &g_iRecvBufSize,sizeof(int));
if (0 > iRet)
{ perror("[Error]Set socket option");
close(fd);
return -1;
}
/* 获取物理网卡接口索引 */
strcpy(stIf.ifr_name, g_szIfName);
iRet = ioctl(fd, SIOCGIFINDEX, &stIf);
if (0 > iRet)
{ perror("[Error]Ioctl operation");
close(fd);
return -1;
}
/* 绑定物理网卡 */
stLocal.sll_family = PF_PACKET;
stLocal.sll_ifindex = stIf.ifr_ifindex;
stLocal.sll_protocol = htons(ETH_P_ALL);
iRet = bind(fd, (struct sockaddr *)&stLocal, sizeof(stLocal));
if (0 > iRet)
{ perror("[Error]Bind the interface");
close(fd);
return -1;
}
return fd;
}
/* 解析Ethernet帧首部 */
static int ethmp_parseEthHead(const struct ether_header *pstEthHead)
{ unsigned short usEthPktType;
if (NULL == pstEthHead)
{ return -1;}
/* 协议类型、源MAC、目的MAC */
usEthPktType = ntohs(pstEthHead->ether_type);
printf(">>>\nEth-Pkt-Type:0x%04x(%s) ", usEthPktType, ethmp_getProName(usEthPktType));
ethmp_showMac(0, pstEthHead->ether_shost);
ethmp_showMac(1, pstEthHead->ether_dhost);
return 0;
}
/* 解析IP数据包头 */
static int ethmp_parseIpHead(const struct ip *pstIpHead)
{ struct protoent *pstIpProto = NULL;
if (NULL == pstIpHead)
{ return -1;}
/* 协议类型、源IP地址、目的IP地址 */
pstIpProto = getprotobynumber(pstIpHead->ip_p);
if(NULL != pstIpProto)
{ printf("\nIP-Pkt-Type:%d(%s) ", pstIpHead->ip_p, pstIpProto->p_name); }
else
{ printf("\nIP-Pkt-Type:%d(%s) ", pstIpHead->ip_p, "None");}
printf("SAddr=[%s] ", inet_ntoa(pstIpHead->ip_src));
printf("DAddr=[%s]\n", inet_ntoa(pstIpHead->ip_dst));
return 0;
}
/* 数据帧解析函数 */
static int ethmp_parseFrame(const char *pcFrameData)
{ int iRet = -1;
struct ether_header *pstEthHead = NULL;
struct ip *pstIpHead = NULL;
/* Ethnet帧头解析 */
pstEthHead = (struct ether_header*)g_acRecvBuf;
iRet = ethmp_parseEthHead(pstEthHead);
if (0 > iRet)
{ return iRet;}
/* IP数据包类型 */
pstIpHead = (struct ip *)(pstEthHead + 1);
iRet = ethmp_parseIpHead(pstIpHead);
return iRet;
}
/* 捕获网卡数据帧 */
static void ethmp_startCapture(const int fd)
{ int iRet = -1;
socklen_t stFromLen = 0;
/* 循环监听 */
while(1)
{ /* 清空接收缓冲区 */
memset(g_acRecvBuf, 0, RCV_BUF_SIZE);
/* 接收数据帧 */
iRet = recvfrom(fd, g_acRecvBuf, g_iRecvBufSize, 0, NULL, &stFromLen);
if (0 > iRet)
{ continue;}
/* 解析数据帧 */
ethmp_parseFrame(g_acRecvBuf);
}
}
/* Main */
int main(int argc, char *argv[])
{ int iRet = -1;
int fd = -1;
/* 初始化SOCKET */
fd = ethmp_initSocket();
if(0 > fd) {
return -1;
}
/* 捕获数据包 */
ethmp_startCapture(fd);
/* 关闭SOCKET */
close(fd);
return 0;
}
编译命令
gcc -o a a.c
./a
实现效果图
...
>>>Eth-Pkt-Type:0x0800(ip) SMAC=[00:1a:92:ef:b6:dd] DMAC=[00:24:7e:dc:99:18] IP-Pkt-Type:6(tcp) SAddr=[192.168.0.111] DAddr=[192.168.0.100]
>>> Eth-Pkt-Type:0x0800(ip) SMAC=[00:24:7e:dc:99:18] DMAC=[00:1a:92:ef:b6:dd] IP-Pkt-Type:6(tcp) SAddr=[192.168.0.100] DAddr=[192.168.0.111]
>>> Eth-Pkt-Type:0x0800(ip) SMAC=[00:24:7e:dc:99:18] DMAC=[00:1a:92:ef:b6:dd] IP-Pkt-Type:1(icmp) SAddr=[192.168.0.100] DAddr=[192.168.0.111]
>>> Eth-Pkt-Type:0x0800(ip) SMAC=[00:1a:92:ef:b6:dd] DMAC=[00:24:7e:dc:99:18] IP-Pkt-Type:1(icmp) SAddr=[192.168.0.111] DAddr=[192.168.0.100]
>>> Eth-Pkt-Type:0x0800(ip) SMAC=[00:1a:92:ef:b6:dd] DMAC=[00:24:7e:dc:99:18] IP-Pkt-Type:6(tcp) SAddr=[192.168.0.111] DAddr=[192.168.0.100]
...
When dealing with a new thing, there are only two results, acceptance or rejection. There are only two endings for this new thing, to be accepted or rejected. The whole process is repeated and tortuous. Now bitcoin is like this. Some people accept it, some refuse it, and some countries support it, some refuse it. But in the end, its outcome depends on this repeated process of convergence, all aspects of the seesaw, all aspects of the struggle, if it survives, then it is real gold, if it is eliminated, then it is false proposition. I can't see the end of it at the moment

pi network aims to realize a low access and low-cost cryptocurrency network that everyone can participate in. Anyone can start mining as long as they download the app of the official website with their mobile phone, and all the users can enjoy the benefits π All are g out by users themselves.
Bitcoin was born in January 2009, on November 29, 2017, the price of bitcoin exceeded US $10000 for the first time , with a market value of nearly US $170 billion, and climbed to an all-time high of US $20000 on December 19. Since then, bitcoin prices have fluctuated sharply. In March 2018, the price of bitcoin fell below US $10000 and dropped below US $4000 at the end of the year
in April 2019, the price of bitcoin went up all the way , climbed to above $12000 in July, recovered to below $10000 at the end of August, fell below $8000 in late September, and then fluctuated between $7000 and $9000
since 2020, the price of bitcoin has broken through the 10000 yuan mark in February, then dropped below US $4000 in the next month, and has been above US $10000 since August< in the morning of November 6, the price of bitcoin was close to US $16000 , and the unit price had exceeded RMB 100000, up 12% in 24 hours. Compared with the lowest price in March 2020, the price of bitcoin has increased by nearly 300%
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extended data
bitcoin has a strong scarcity:
unlike all currencies, bitcoin does not rely on a specific monetary institution to issue, it is based on a specific algorithm, through a large number of calculations, Bitcoin economy uses the distributed database composed of many nodes in the whole P2P network to confirm and record all transactions, and uses the design of cryptography to ensure the security of all aspects of money circulation
the decentralized feature and algorithm of P2P can ensure that it is impossible to artificially control the value of bitcoin by mass manufacturing. The design based on cryptography can make bitcoin only be transferred or paid by the real owner. This also ensures the anonymity of money ownership and circulation transactions. The biggest difference between bitcoin and other virtual currencies is that the total amount of bitcoin is very limited and it has a strong scarcity
