閱讀目錄

• 　　HTTP請求和IP/TCP
• 　　實現GET請求
• 　　實現POST請求：
• 　　參考：

回到頂部

　　HTTP請求和IP/TCP

　　所謂的HTTP協議是基于IP/TCP協議的， 所以要獲取遠端的html數據只要創建socket對象就足夠了；

　　HTTP是基于IP/TCP加上了網絡請求的固定格式， 比如：?

運行下面代碼

method URL Content-host Content-Type Content-Length

回到頂部

　　實現GET請求

　　把組合成的數據按照固定的格式發送給服務器， 服務器解析相應的格式， 然后返回服務器數據：

運行下面代碼

#include <stdio.h> #include <sys/socket.h> #include <sys/types.h> #include <time.h> #include <errno.h> #include <signal.h> #include <stdlib.h> #include <string.h> #include <unistd.h> #include <sys/wait.h> #include <sys/time.h> #include <netinet/in.h> #include <arpa/inet.h>#define IPSTR "42.121.252.58" //服務器IP地址; #define PORT 80 #define BUFSIZE 1024int main(int argc, char **argv) {int sockfd, ret, i, h;struct sockaddr_in servaddr;char str1[4096], str2[4096], buf[BUFSIZE], *str;socklen_t len;fd_set t_set1;struct timeval tv;//創建套接字if ((sockfd = socket(AF_INET, SOCK_STREAM, 0)) < 0 ) {printf("創建網絡連接失敗,本線程即將終止---socket error!\n");exit(0);};bzero(&servaddr, sizeof(servaddr));servaddr.sin_family = AF_INET;servaddr.sin_port = htons(PORT);if (inet_pton(AF_INET, IPSTR, &servaddr.sin_addr) <= 0 ){printf("創建網絡連接失敗,本線程即將終止--inet_pton error!\n");exit(0);};if (connect(sockfd, (struct sockaddr *)&servaddr, sizeof(servaddr)) < 0){printf("連接到服務器失敗,connect error!\n");exit(0);}printf("與遠端建立了連接\n");memset(str2, 0, 4096);strcat(str2, "theDataToPost");str=(char *)malloc(128);len = strlen(str2);sprintf(str, "%d", len);memset(str1, 0, 4096);strcat(str1, "GET /ymnets/p/6255674.html HTTP/1.1\n");strcat(str1, "Host: www.cnblogs.com\n");strcat(str1, "Content-Type: text/html\n");strcat(str1, "Content-Length: ");strcat(str1, str);strcat(str1, "\n\n");strcat(str1, str2);strcat(str1, "\r\n\r\n");printf("%s\n",str1);ret = write(sockfd,str1,strlen(str1));if (ret < 0) {printf("發送失敗！錯誤代碼是%d，錯誤信息是'%s'\n",errno, strerror(errno));exit(0);}else{printf("消息發送成功，共發送了%d個字節！\n\n", ret);}FD_ZERO(&t_set1);FD_SET(sockfd, &t_set1);while(1){sleep(2);tv.tv_sec= 0;tv.tv_usec= 0;h= 0;printf("--------------->1");h= select(sockfd +1, &t_set1, NULL, NULL, &tv);printf("--------------->2");//if (h == 0) continue;if (h < 0) {close(sockfd);printf("在讀取數據報文時SELECT檢測到異常，該異常導致線程終止！\n");return -1;};if (h > 0){memset(buf, 0, 4096);i= read(sockfd, buf, 4095);if (i==0){close(sockfd);printf("讀取數據報文時發現遠端關閉，該線程終止！\n");return -1;}printf("%s\n", buf);}}close(sockfd);return 0; }

回到頂部

　　實現POST請求：

　　C實現POST請求參考代碼， 只要把請求類型從GET改為POST， 然后把請求的數據代入到請求頭中即可：

運行下面代碼

#include <stdio.h> #include <sys/socket.h> #include <sys/types.h> #include <time.h> #include <errno.h> #include <signal.h> #include <stdlib.h> #include <string.h> #include <unistd.h> #include <sys/wait.h> #include <sys/time.h> #include <netinet/in.h> #include <arpa/inet.h>#define IPSTR "61.147.124.120" #define PORT 80 #define BUFSIZE 1024int main(int argc, char **argv) {int sockfd, ret, i, h;struct sockaddr_in servaddr;char str1[4096], str2[4096], buf[BUFSIZE], *str;socklen_t len;fd_set t_set1;struct timeval tv;if ((sockfd = socket(AF_INET, SOCK_STREAM, 0)) < 0 ) {printf("創建網絡連接失敗,本線程即將終止---socket error!\n");exit(0);};bzero(&servaddr, sizeof(servaddr));servaddr.sin_family = AF_INET;servaddr.sin_port = htons(PORT);if (inet_pton(AF_INET, IPSTR, &servaddr.sin_addr) <= 0 ){printf("創建網絡連接失敗,本線程即將終止--inet_pton error!\n");exit(0);};if (connect(sockfd, (struct sockaddr *)&servaddr, sizeof(servaddr)) < 0){printf("連接到服務器失敗,connect error!\n");exit(0);}printf("與遠端建立了連接\n");memset(str2, 0, 4096);strcat(str2, "qqCode=287101329");str=(char *)malloc(128);len = strlen(str2);sprintf(str, "%d", len);memset(str1, 0, 4096);strcat(str1, "POST /webservices/qqOnlineWebService.asmx/qqCheckOnline HTTP/1.1\n");strcat(str1, "Host: www.webxml.com.cn\n");strcat(str1, "Content-Type: application/x-www-form-urlencoded\n");strcat(str1, "Content-Length: ");strcat(str1, str);strcat(str1, "\n\n");//str2的值為post的數據strcat(str1, str2);strcat(str1, "\r\n\r\n");printf("%s\n",str1);ret = write(sockfd,str1,strlen(str1));if (ret < 0) {printf("發送失敗！錯誤代碼是%d，錯誤信息是'%s'\n",errno, strerror(errno));exit(0);}else{printf("消息發送成功，共發送了%d個字節！\n\n", ret);}FD_ZERO(&t_set1);FD_SET(sockfd, &t_set1);while(1){sleep(2);tv.tv_sec= 0;tv.tv_usec= 0;h= 0;printf("--------------->1");h= select(sockfd +1, &t_set1, NULL, NULL, &tv);printf("--------------->2");//if (h == 0) continue;if (h < 0) {close(sockfd);printf("在讀取數據報文時SELECT檢測到異常，該異常導致線程終止！\n");return -1;};if (h > 0){memset(buf, 0, 4096);i= read(sockfd, buf, 4095);if (i==0){close(sockfd);printf("讀取數據報文時發現遠端關閉，該線程終止！\n");return -1;}printf("%s\n", buf);}}close(sockfd);return 0; }

　　POST請求的方式可以再改改：

運行下面代碼

#include <stdio.h> #include <sys/socket.h> #include <sys/types.h> #include <time.h> #include <errno.h> #include <signal.h> #include <stdlib.h> #include <string.h> #include <unistd.h> #include <sys/wait.h> #include <sys/time.h> #include <netinet/in.h> #include <arpa/inet.h>#define IPSTR "61.147.124.120" #define PORT 80 #define BUFSIZE 1024int main(int argc, char **argv) {int sockfd, ret, i, h;struct sockaddr_in servaddr;char str1[4096], str2[4096], buf[BUFSIZE], *str;socklen_t len;fd_set t_set1;struct timeval tv;if ((sockfd = socket(AF_INET, SOCK_STREAM, 0)) < 0 ) {printf("創建網絡連接失敗,本線程即將終止---socket error!\n");exit(0);};bzero(&servaddr, sizeof(servaddr));servaddr.sin_family = AF_INET;servaddr.sin_port = htons(PORT);if (inet_pton(AF_INET, IPSTR, &servaddr.sin_addr) <= 0 ){printf("創建網絡連接失敗,本線程即將終止--inet_pton error!\n");exit(0);};if (connect(sockfd, (struct sockaddr *)&servaddr, sizeof(servaddr)) < 0){printf("連接到服務器失敗,connect error!\n");exit(0);}printf("與遠端建立了連接\n");memset(str2, 0, 4096);strcat(str2, "qqCode=287101329");str=(char *)malloc(128);len = strlen(str2);sprintf(str, "%d", len);memset(str1, 0, 4096);strcat(str1, "POST /webservices/qqOnlineWebService.asmx/qqCheckOnline HTTP/1.1\n");strcat(str1, "Host: www.webxml.com.cn\n");strcat(str1, "Content-Type: application/x-www-form-urlencoded\n");strcat(str1, "Content-Length: ");strcat(str1, str);strcat(str1, "\n\n");//str2的值為post的數據strcat(str1, str2);strcat(str1, "\r\n\r\n");printf("%s\n",str1);ret = write(sockfd,str1,strlen(str1));if (ret < 0) {printf("發送失敗！錯誤代碼是%d，錯誤信息是'%s'\n",errno, strerror(errno));exit(0);}else{printf("消息發送成功，共發送了%d個字節！\n\n", ret);}FD_ZERO(&t_set1);FD_SET(sockfd, &t_set1);tv.tv_sec= 0;tv.tv_usec= 0;h= 0;while(1){sleep(2);printf("--------------->1");h = select(sockfd +1, &t_set1, NULL, NULL, &tv);printf("--------------->2");//if (h == 0) continue;if (h == -1) {close(sockfd);printf("在讀取數據報文時SELECT檢測到異常，該異常導致線程終止！\n");return -1;};if ( FD_ISSET(sockfd, &t_set1) ){memset(buf, 0, 4096);i= read(sockfd, buf, 4095);if (i==0){close(sockfd);printf("讀取數據報文時發現遠端關閉，該線程終止！\n");return -1;}printf("%s\n", buf);}}close(sockfd);return 0; }

　　請求一個HTTP服務器的數據， 接收一個參數為請求的服務器IP：

運行下面代碼

#include <stdio.h> #include <stdlib.h> #include <string.h> #include <sys/types.h> #include <sys/socket.h> #include <arpa/inet.h> #include <netinet/in.h> #include <unistd.h>int main(int argc, char *argv[]){ if(argc!=2){printf("error usage %s ip\n",argv[0]); return 1;} int sockfd;int len; struct sockaddr_in address; int result; char httpstring[100]; sprintf(httpstring,"GET / HTTP/1.1\r\n""Host: %s\r\n""Connection: Close\r\n\r\n",argv[1]); char ch; sockfd = socket(AF_INET, SOCK_STREAM, 0); address.sin_family = AF_INET; address.sin_addr.s_addr = inet_addr(argv[1]); address.sin_port = htons(80); len = sizeof(address);result = connect(sockfd,(struct sockaddr *)&address,len); if(result == -1){ perror("oops: client"); return 1; }write(sockfd,httpstring,strlen(httpstring)); while(read(sockfd,&ch,1)){ printf("%c", ch); } close(sockfd); printf("\n"); return 0; }

　　使用gcc編譯以后執行：?sudo ./req 42.121.252.58

回到頂部

　　參考：

　　Linux下用c語言實現發送http請求 方式可以Get或者Post：http://www.oschina.net/code/snippet_176076_5908/

總結

以上是生活随笔為你收集整理的C++/C语言实现HTTP的GET和POST请求的全部內容，希望文章能夠幫你解決所遇到的問題。

如果覺得生活随笔網站內容還不錯，歡迎將生活随笔推薦給好友。