c语言发送邮件（收藏）转

时间：2011-01-03 来源：jerryking

领导交代一个任务，需要将服务器上的df -hl的执行结果定时发给他。

尝试使用sendmail来发邮件，但是后来放弃了，并不是所有的服务器上都安装了sendmail。

于是，就用c写一个吧，还能够指定邮件服务器地址和端口，会更灵活些。

目标是创建程序qmail，然后通过命令qmail [email protected] your.txt将your.txt的内容发送给[email protected]。

在网上找了半天，没有一个例子能够完全跑起来，有些是提问题的，最总问题解决了却不告诉别人，这人真可恨。

虽然这些代码都是复制粘贴来的，但是本着公益的宗旨，就不追究版权了。

1
  2 #include <stdio.h>
  3 #include <sys/socket.h>
  4 #include <sys/types.h>
  5 #include <netinet/in.h>
  6 #include <stdlib.h>
  7 #include <string.h>
  8
  9 int main(int argc,char *argv[])
10 {
11     int sockfd = -1;
12     int iconn = -2;
13     ssize_t retConnect = -2;
14     struct sockaddr_in servaddr;
15     char ip[20] = "192.168.0.251";//设置SMTP地址
16     char sentmsg[2048] = "";
17     char buf[255] = "";
18     char fileContent[1024] = "";
19     FILE* file;
20     char cin[255] = "";
21
22     int len = 0;
23     while(!(argv[len]==NULL))
24     {
25         len++;
26     }
27
28     if(len!=3)
29     {
30         printf("Usage:qmail [email protected] df.log\n");
31         exit(0);
32     }
33     memset(fileContent,'\0',sizeof(fileContent));
34     if((file = fopen(argv[2], "r")) == NULL)
35         printf("Not find file");
36     else
37     {
38         while(fgets(cin, sizeof(cin), file) != NULL)
39         {
40             strcat(fileContent,cin);
41             memset(cin,'\0',sizeof(cin));
42         }
43     }
44     fclose(file);
45     printf("%s",fileContent);
46     setvbuf(stdout,NULL,_IONBF,0);
47     sockfd = socket(AF_INET,SOCK_STREAM,0);//以scoket方式和邮件服务器通讯
48     if(sockfd>0)
49     {
50         printf("socket is open");
51         bzero(&servaddr,sizeof(servaddr));
52         servaddr.sin_family=AF_INET;
53         servaddr.sin_port=htons(25);
54         inet_pton(AF_INET,ip,&servaddr.sin_addr);
55         iconn = connect(sockfd,(struct sockaddr *)&servaddr,sizeof(servaddr));
56         if(iconn==0)
57         {
58             printf("connect to 192.168.0.251 25 success!");
59             retConnect = recv(sockfd,buf,sizeof(buf),0);
60             if(retConnect==-1)
61             {
62                 printf("Failed to receive msg from smtp port");
63             }
64             else
65                 printf("\nServer:%s\n",buf);
66             memset(sentmsg,'\0',sizeof(sentmsg));
67             strcpy(sentmsg,"HELO SERVER\r\n");
68             retConnect = send(sockfd,sentmsg,strlen(sentmsg),0);
69             if(retConnect==-1)
70             {
71                 printf("\nFailed to send meg to smtp port in step 2.\n");
72                 exit(1);
73             }
74             else
75             {
76                 printf("%s",sentmsg);
77             }
78             memset(buf,'\0',sizeof(buf));
79             retConnect=recv(sockfd,buf,sizeof(buf),0);
80             if(retConnect == -1)
81             {
82                 printf("\nFailed to recive meg from smtp port in step 3.\n");
83                 exit(1);
84             }
85             else
86             {
87                 printf("%s\n",buf);
88             }
89
90                         memset(sentmsg,'\0',sizeof(sentmsg));
91                         strcpy(sentmsg,"MAIL FROM: [email protected]\r\n");
92                         strcat(sentmsg,"RCPT TO: ");
93                         strcat(sentmsg,argv[1]);
94                         strcat(sentmsg,"\r\n");
95                         retConnect = send(sockfd,sentmsg,strlen(sentmsg),0);
96                         if(retConnect>0)
97                             printf("%s",sentmsg);
98                         memset(buf,'\0',sizeof(buf));
99                         retConnect=recv(sockfd,buf,sizeof(buf),0);
100                         if(retConnect>0)
101                             printf("%s\n",buf);
102
103                         memset(sentmsg,'\0',sizeof(sentmsg));
104                         strcpy(sentmsg,"DATA\r\n");
105                         retConnect = send(sockfd,sentmsg,strlen(sentmsg),0);
106                         if(retConnect>0)
107                             printf("%s",sentmsg);
108                         memset(buf,'\0',sizeof(buf));
109                         retConnect=recv(sockfd,buf,sizeof(buf),0);
110                         if(retConnect>0)
111                             printf("%s\n",buf);
112
113                         memset(sentmsg,'\0',sizeof(sentmsg));
114                         strcpy(sentmsg,"From:[email protected]\r\n");
115                         strcat(sentmsg,"To:");
116                         strcat(sentmsg,argv[1]);
117                         strcat(sentmsg,"\r\n");
118                         strcat(sentmsg,"Subject:QDCM Host Check Data\r\n\r\n");
119                         strcat(sentmsg,fileContent);
120                         strcat(sentmsg,"\r\n");
121                         strcat(sentmsg,"\r\n.\r\n");
122                         retConnect = send(sockfd,sentmsg,strlen(sentmsg),0);
123                         memset(sentmsg,'\0',sizeof(sentmsg));
124
125                         strcpy(sentmsg,"QUIT\r\n");
126                         retConnect = send(sockfd,sentmsg,strlen(sentmsg),0);
127                         if(retConnect>0)
128                             printf("%s",sentmsg);
129                         memset(buf,'\0',sizeof(buf));
130                         retConnect=recv(sockfd,buf,sizeof(buf),0);
131                         if(retConnect>0)
132                             printf("%s\n",buf);
133
134         }
135         else
136         {
137             printf("connect 192.168.0.251 25 failed!");
138             sleep(1);
139         }
140         close(sockfd);
141     }
142     else
143     {
144         printf("open socket failed!");
145     }
146     return 0;
147 }
148

使用gcc编译

如果你是在高版本的linux下编译的，在低版本上的linux使用时会报错

此时需要在编译时追加参数：

gcc -Wl,--hash-style=sysv qmail.c -o qmail