linux c socket 实现http get/post请求

文件 getHtml.c

#include <stdio.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <stdlib.h>
#include <netdb.h>
#include <string.h>
#include <fcntl.h>

int create_tcp_socket();
char *get_ip(char *host);
char *build_get_query(char *host,char *page);
void usage();

#define HOST "www.baidu.com"
#define PAGE "/"
#define PORT 80
#define USERAGENT "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/30.0.1599.114 Safari/537.36"
#define ACCEPTLANGUAGE "zh-CN,zh;q=0.8,en;q=0.6,en-US;q=0.4,en-GB;q=0.2"
#define ACCEPTENCODING "gzip,deflate,sdch"

int main(int argc,char **argv){
struct sockaddr_in *remote;
int sock;
int tmpres;
char *ip;
char *get;
char buf[BUFSIZ+1];
char *host;
char *page;

if(argc==1){
usage();
exit(2);
}
host=argv[1];
if(argc>2){
page=argv[2];
}else{
page=PAGE;
}
fprintf(stdout,"page:%s,hostName:%s\n",page,host);
sock=create_tcp_socket();
ip=get_ip(host);
fprintf(stderr,"IP is %s\n",ip);
remote=(struct sockaddr_in *)malloc(sizeof(struct sockaddr_in*));
remote->sin_family=AF_INET;
tmpres=inet_pton(AF_INET,ip,(void *)(&(remote->sin_addr.s_addr)));
if(tmpres<0){
perror("Can't set remote->sin_addr.s_addr");
exit(1);
}else if(tmpres==0){
fprintf(stderr,"%s is not a valid IP address\n",ip);
exit(1);
}
remote->sin_port=htons(PORT);
if(connect(sock,(struct sockaddr *)remote,sizeof(struct sockaddr))<0){
perror("Could not connect!\n");
exit(1);
}
get =build_get_query(host,page);
fprintf(stdout,"<start>\n%s\n<end>\n",get);
int sent=0;
while(sent<strlen(get)){
tmpres=send(sock,get+sent,strlen(get)-sent,0);
if(tmpres==-1){
perror("Can't send query!");
exit(1);
}
sent+=tmpres;
}
memset(buf,0,sizeof(buf));
int htmlstart=0;
char *htmlcontent;
while((tmpres=recv(sock,buf,BUFSIZ,0))>0){
if(htmlstart==0){
htmlcontent=strstr(buf,"\r\n\r\n");
if(htmlcontent!=NULL){
htmlstart=1;
htmlcontent+=4;
}
}else{
htmlcontent=buf;
}
if(htmlstart){
fprintf(stdout,htmlcontent);
}
memset(buf,0,tmpres);
// fprintf(stdout,"\n\n\ntmpres Value:%d\n",tmpres);
}
fprintf(stdout,"receive data over!\n");
if(tmpres<0){
perror("Error receiving data!\n");
}
free(get);
free(remote);
free(ip);
close(sock);
return 0;
}
void usage(){
fprintf(stderr,"USAGE:htmlget host [page]\n\thost:the website hostname. ex:www.baidu.com\n\tpage:the page to retrieve. ex:index.html,default:/\n");
}
int create_tcp_socket(){
int sock;
if((sock=socket(AF_INET,SOCK_STREAM,IPPROTO_TCP))<0){
perror("Can't create TCP socket!\n");
exit(1);
}
return sock;
}
char *get_ip(char *host){
struct hostent *hent;
int iplen=15;
char *ip=(char *)malloc(iplen+1);
memset(ip,0,iplen+1);
if((hent=gethostbyname(host))==NULL){
perror("Can't get ip");
exit(1);
}
if(inet_ntop(AF_INET,(void *)hent->h_addr_list[0],ip,iplen)==NULL){
perror("Can't resolve host!\n");
exit(1);
}
return ip;
}
char *build_get_query(char *host,char *page){
char *query;
char *getpage=page;
char *tpl="GET %s HTTP/1.1\r\nHost:%s\r\nAccept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8\r\nUser-Agent:%s\r\nAccept-Language:%s\r\n\r\n";//Accept-Encoding:%s\r\n
query=(char *)malloc(strlen(host)+strlen(getpage)+strlen(USERAGENT)+strlen(tpl)+strlen(ACCEPTLANGUAGE)-5);//+strlen(ACCEPTENCODING)
sprintf(query,tpl,getpage,host,USERAGENT,ACCEPTLANGUAGE);//ACCEPTENCODING
return query;
}