C语言实现简单的SMTP发送邮件
#include <windows.h>
#include <stdio.h>
#include <WinSock.h>
#include <iostream>
using namespace std
#pragma comment(lib, "ws2_32.lib")
struct Base64Date6
{
unsigned int d4:6
unsigned int d3:6
unsigned int d2:6
unsigned int d1:6
}
// 协议中加密部分使用的是base64方法
char ConvertToBase64 (char c6)
void EncodeBase64 (char *dbuf, char *buf128, int len)
void SendMail (char *email,char *body)
int OpenSocket (struct sockaddr *addr)
int main()
{
char EmailTo[] = "[email protected]"
char EmailContents[] = "From: \"lucy\"[email protected]>\r\n"
"To: \"dasiy\"[email protected]>\r\n"
"Subject: Hello\r\n\r\n"
"Hello World, Hello Email!"
SendMail(EmailTo, EmailContents)
return 0
}
char ConvertToBase64(char uc)
{
if(uc <26)
{
return 'A' + uc
}
if(uc <52)
{
return 'a' + (uc - 26)
}
if(uc <62)
{
return '0' + (uc - 52)
}
if(uc == 62)
{
return '+'
}
return '/'
}
// base64的实现
void EncodeBase64(char *dbuf, char *buf128, int len)
{
struct Base64Date6 *ddd = NULL
int i= 0
char buf[256] = {0}
char *tmp = NULL
char cc = '\0'
memset(buf, 0, 256)
strcpy_s(buf, 256, buf128)
for(i = 1i <= len/3i++)
{
tmp = buf + (i-1)*3
cc = tmp[2]
tmp[2] = tmp[0]
tmp[0] = cc
ddd = (struct Base64Date6 *)tmp
dbuf[(i-1)*4+0] = ConvertToBase64((unsigned int)ddd->d1)
dbuf[(i-1)*4+1] = ConvertToBase64((unsigned int)ddd->d2)
dbuf[(i-1)*4+2] = ConvertToBase64((unsigned int)ddd->d3)
dbuf[(i-1)*4+3] = ConvertToBase64((unsigned int)ddd->d4)
}
if(len % 3 == 1)
{
tmp = buf + (i-1)*3
cc = tmp[2]
tmp[2] = tmp[0]
tmp[0] = cc
ddd = (struct Base64Date6 *)tmp
dbuf[(i-1)*4+0] = ConvertToBase64((unsigned int)ddd->d1)
dbuf[(i-1)*4+1] = ConvertToBase64((unsigned int)ddd->d2)
dbuf[(i-1)*4+2] = '='
dbuf[(i-1)*4+3] = '='
}
if(len%3 == 2)
{
tmp = buf+(i-1)*3
cc = tmp[2]
tmp[2] = tmp[0]
tmp[0] = cc
ddd = (struct Base64Date6 *)tmp
dbuf[(i-1)*4+0] = ConvertToBase64((unsigned int)ddd->d1)
dbuf[(i-1)*4+1] = ConvertToBase64((unsigned int)ddd->d2)
dbuf[(i-1)*4+2] = ConvertToBase64((unsigned int)ddd->d3)
dbuf[(i-1)*4+3] = '='
}
return
}
// 发送邮件
void SendMail(char *email, char *body)
{
int sockfd = {0}
charbuf[1500] = {0}
charrbuf[1500] = {0}
charlogin[128] = {0}
charpass[128] = {0}
WSADATA WSAData
struct sockaddr_in their_addr = {0}
WSAStartup(MAKEWORD(2, 2), &WSAData)
memset(&their_addr, 0, sizeof(their_addr))
their_addr.sin_family = AF_INET
their_addr.sin_port = htons(25)
hostent* hptr = gethostbyname("smtp.126.com")
memcpy(&their_addr.sin_addr.S_un.S_addr, hptr->h_addr_list[0], hptr->h_length)
printf("IP of smpt.126.com is : %d:%d:%d:%d\n",
their_addr.sin_addr.S_un.S_un_b.s_b1,
their_addr.sin_addr.S_un.S_un_b.s_b2,
their_addr.sin_addr.S_un.S_un_b.s_b3,
their_addr.sin_addr.S_un.S_un_b.s_b4)
// 连接邮件服务器，如果连接后没有响应，则2 秒后重新连接
sockfd = OpenSocket((struct sockaddr *)&their_addr)
memset(rbuf, 0, 1500)
while(recv(sockfd, rbuf, 1500, 0) == 0)
{
cout<<"reconnect..."<<endl
Sleep(2)
sockfd = OpenSocket((struct sockaddr *)&their_addr)
memset(rbuf, 0, 1500)
}
cout<<rbuf<<endl
// EHLO
memset(buf, 0, 1500)
sprintf_s(buf, 1500, "EHLO HYL-PC\r\n")
send(sockfd, buf, strlen(buf), 0)
memset(rbuf, 0, 1500)
recv(sockfd, rbuf, 1500, 0)
cout<<"EHLO REceive: "<<rbuf<<endl
// AUTH LOGIN
memset(buf, 0, 1500)
sprintf_s(buf, 1500, "AUTH LOGIN\r\n")
send(sockfd, buf, strlen(buf), 0)
memset(rbuf, 0, 1500)
recv(sockfd, rbuf, 1500, 0)
cout<<"Auth Login Receive: "<<rbuf<<endl
// USER
memset(buf, 0, 1500)
sprintf_s(buf, 1500, "[email protected]")//你的邮箱账号
memset(login, 0, 128)
EncodeBase64(login, buf, strlen(buf))
sprintf_s(buf, 1500, "%s\r\n", login)
send(sockfd, buf, strlen(buf), 0)
cout<<"Base64 UserName: "<<buf<<endl
memset(rbuf, 0, 1500)
recv(sockfd, rbuf, 1500, 0)
cout<<"User Login Receive: "<<rbuf<<endl
// PASSWORD
sprintf_s(buf, 1500, "XXXXXXXXXXXX")//你的邮箱密码
memset(pass, 0, 128)
EncodeBase64(pass, buf, strlen(buf))
sprintf_s(buf, 1500, "%s\r\n", pass)
send(sockfd, buf, strlen(buf), 0)
cout<<"Base64 Password: "<<buf<<endl
memset(rbuf, 0, 1500)
recv(sockfd, rbuf, 1500, 0)
cout<<"Send Password Receive: "<<rbuf<<endl
// MAIL FROM
memset(buf, 0, 1500)
sprintf_s(buf, 1500, "MAIL FROM: [email protected]>\r\n")
send(sockfd, buf, strlen(buf), 0)
memset(rbuf, 0, 1500)
recv(sockfd, rbuf, 1500, 0)
cout<<"set Mail From Receive: "<<rbuf<<endl
// RCPT TO 第一个收件人
sprintf_s(buf, 1500, "RCPT TO:<%s>\r\n", email)
send(sockfd, buf, strlen(buf), 0)
memset(rbuf, 0, 1500)
recv(sockfd, rbuf, 1500, 0)
cout<<"Tell Sendto Receive: "<<rbuf<<endl
// DATA 准备开始发送邮件内容
sprintf_s(buf, 1500, "DATA\r\n")
send(sockfd, buf, strlen(buf), 0)
memset(rbuf, 0, 1500)
recv(sockfd, rbuf, 1500, 0)
cout<<"Send Mail Prepare Receive: "<<rbuf<<endl
// 发送邮件内容，\r\n.\r\n内容结束标记
sprintf_s(buf, 1500, "%s\r\n.\r\n", body)
send(sockfd, buf, strlen(buf), 0)
memset(rbuf, 0, 1500)
recv(sockfd, rbuf, 1500, 0)
cout<<"Send Mail Receive: "<<rbuf<<endl
// QUIT
sprintf_s(buf, 1500, "QUIT\r\n")
send(sockfd, buf, strlen(buf), 0)
memset(rbuf, 0, 1500)
recv(sockfd, rbuf, 1500, 0)
cout<<"Quit Receive: "<<rbuf<<endl
//清理工作
closesocket(sockfd)
WSACleanup()
return
}
// 打开TCP Socket连接
int OpenSocket(struct sockaddr *addr)
{
int sockfd = 0
sockfd=socket(PF_INET, SOCK_STREAM, 0)
if(sockfd <0)
{
cout<<"Open sockfd(TCP) error!"<<endl
exit(-1)
}
if(connect(sockfd, addr, sizeof(struct sockaddr)) <0)
{
cout<<"Connect sockfd(TCP) error!"<<endl
exit(-1)
}
return sockfd
}
#include "stdio.h"void main()
{
float a,b
printf("请输入包裹的重量(公斤)：\n")
scanf("%f",&a)
if(a<=1)
b=1.5
else
{
b=1.5+(a-1)*0.8
}
printf("此包裹的邮费为：%.2f元",b)
}
#include<iostream>using namespace std
int main()
{
float a
cin>>a
if(a<=1)cout<<1.5*a<<endl
if(a>1)cout<<1.5+2.3*a<<endl
return 0
}
第二题：#include<iostream>
using namespace std
int main()
{
int a,b1,b2,b3,c
cin>>a
b1=a/100
b2=a%100/10
b3=a%10
if(b2<b3)
{c=b3b3=b2b2=c}
if(b1<b2)
{c=b2b2=b1b1=c}
if(b2<b3)
{c=b3b3=b2b2=c}
cout<<b1*100+b2*10+b3<<endl
return 0
}
