可能大家经常要去互联网上搜索特定的内容，比如收集大量邮件地址，如果用google之类的搜索引擎是没法实现这种特定功能的，所以用C语言来写一个吧。它的功能就是不断去取得网络上的页面，然后分析出网页上出现的邮件地址保存下来。象个蜘蛛一样，从网络上一个网页爬向另一个网页，不停止地搜索邮件地址。当然这只是一个原理展示程序，并没有进行优化。这个程序的main函数流程图如下：即：分析程序运行时的参数，把各网页地址作为根节点加入到链表，然后从链表头开始处理各节点对整个链表的处理是先处理兄弟节点，流程图如下：然后再处理各节点的子节点，流程图如下：当然，这里采用了递归调用方法，处理子节点的数据时和处理整个链表一样循环处理就是了。/************关于本文档********************************************
*filename:用C语言编写一个网络蜘蛛来搜索网上出现的电子邮件地址*purpose:一个邮址搜索程序的雏形*wrote by: zhoulifa(zhoulifa@)周立发Linux知识传播者SOHO族开发者 最擅长C语言*date time:-08-31 21:00:00
*Note:任何人可以任意复制代码并运用这些文档，当然包括你的商业用途*但请遵循GPL
*Hope:希望越来越多的人贡献自己的力量，为科学技术发展出力*********************************************************************/程序在运行的过程中要建立一个树形链表结构，结构图如下：程序启动时分析所带参数，把各参数加入到根网页节点，如果有多个参数则这个根网页有兄弟节点。然后从根节点开始处理这一级上各节点，把各节点网页上出现的网页链接加到该节点的子节点上，处理完当前这一级后处理子节点这一级。源代码如下：[code]
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#define USERAGENT "Wget/1.10.2"
#define ACCEPT "*/*"
#define ACCEPTLANGUAGE "zh-cn,zh;q=0.5"
#define ACCEPTENCODING "gzip,deflate"
#define ACCEPTCHARSET "gb2312,utf-8;q=0.7,*;q=0.7"
#define KEEPALIVE "300"
#define CONNECTION "keep-alive"
#define CONTENTTYPE "application/x-www-form-urlencoded"
#define MAXFILENAME 14
#define DEBUG 1
typedef struct webnode {
char * host; /*网页所在的主机*/
int port; /*网络服务器所使用的端口*/
char * dir; /*网页所在的目录*/
char * page; /*网页文件名*/
char * file; /*本地保存的文件名*/
char IsHandled; /*是否处理过*/
struct webnode * brother; /*兄弟节点链表指针*/
struct webnode * child; /*子节点链表指针*/
} WEBNODE;
struct sockaddr_in server_addr;
int sockfd = 0, dsend = 0, totalsend = 0, nbytes = 0, reqn = 0, i = 0, j = 0, ret = 0;
struct hostent *host;
char request[409600] = "", buffer[1024] = "", httpheader[1024] = "";
int FileNumber = 0;
char e[2] = "@/";
WEBNODE * NodeHeader, * NodeTail, * NodeCurr;
char * mapped_mem;
int GetHost(char * , char ** , char ** , int * , char ** ); /**/
void AnalyzePage(WEBNODE *); /**/
void AddInitNode(char *, char *, int, char * ); /**/
void HandleInitNode(WEBNODE *); /**/
void DisplayNode(WEBNODE *); /**/
void HandOneNode(WEBNODE *); /**/
void DoneWithList(int); /**/
void DoOnce(); /**/
void ConnectWeb(void); /**/
void SendRequest(void); /**/
void ReceiveResponse(void); /**/
void GetEmail(char * ); /**/
void GetLink(char * ); /**/
void GetBeforePos(char * , char ** ); /**/
void GetAfterPos(char * , char ** ); /**/
void AddChildNode(WEBNODE * , char * ); /**/
void GetAfterPosWithSlash(char * , char ** ); /**/
void GetMemory(char ** , int ); /**/
int IsExistWeb(WEBNODE * , char * , char * , int , char * ); /**/
void Rstrchr(char * , int , char ** ); /**/
int GetLocalAgent(char * UserAgent, char * Accept, char * AcceptLanguage, char * AcceptEncoding, char * AcceptCharset, char * KeepAlive, char * Connection, char * ContentType); /**/
/**************************************************************功能：设置HTTP协议头内容的一些固定值***************************************************************/
int GetLocalAgent(char * UserAgent, char * Accept, char * AcceptLanguage, char * AcceptEncoding, char * AcceptCharset, char * KeepAlive, char * Connection, char * ContentType)
{
memcpy(UserAgent, USERAGENT, strlen(USERAGENT));
memcpy(Accept, ACCEPT, strlen(ACCEPT));
memcpy(AcceptLanguage, ACCEPTLANGUAGE, strlen(ACCEPTLANGUAGE));
memcpy(AcceptEncoding, ACCEPTENCODING, strlen(ACCEPTENCODING));
memcpy(AcceptCharset, ACCEPTCHARSET, strlen(ACCEPTCHARSET));
memcpy(KeepAlive, KEEPALIVE, strlen(KEEPALIVE));
memcpy(Connection, CONNECTION, strlen(CONNECTION));
memcpy(ContentType, CONTENTTYPE, strlen(CONTENTTYPE));
return 0;
}
/**************************************************************功能：在字符串s里搜索x字符，并设置指针d指向该位置***************************************************************/
void Rstrchr(char * s, int x, char ** d)
{
int len = strlen(s) - 1;
while(len >= 0) {
if(x == s[len]) {(*d) = s + len; return;}
len--;
}
(*d) = 0;
}
/**************************************************************功能：连接一个网站服务器***************************************************************/
void ConnectWeb(void) { /* connect to web server */
/* create a socket descriptor */
if((sockfd=socket(PF_INET,SOCK_STREAM,0))==-1)
{
fprintf(stderr,"\tSocket Error:%s\a\n",strerror(errno));
exit(1);
}
/* bind address */
bzero(&server_addr, sizeof(server_addr));
server_addr.sin_family = AF_INET;
server_addr.sin_port = htons(NodeCurr->port);
server_addr.sin_addr = *((struct in_addr *)host->h_addr);
/* connect to the server */
if(connect(sockfd, (struct sockaddr *)(&server_addr), sizeof(struct sockaddr)) == -1)
{
fprintf(stderr, "\tConnect Error:%s\a\n", strerror(errno));
exit(1);
}
}
/**************************************************************功能：向网站发送HTTP请求***************************************************************/
void SendRequest(void) { /* send my http-request to web server */
dsend = 0;totalsend = 0;
nbytes=strlen(request);
while(totalsend < nbytes) {
dsend = write(sockfd, request + totalsend, nbytes - totalsend);
if(dsend==-1) {fprintf(stderr, "\tsend error!%s\n", strerror(errno));exit(0);}
totalsend+=dsend;
fprintf(stdout, "\n\tRequest.%d %d bytes send OK!\n", reqn, totalsend);
}
}
/**************************************************************功能：接收网站的HTTP返回***************************************************************/
void ReceiveResponse(void) { /* get response from web server */
fd_set writefds;
struct timeval tival;
int retry = 0;
FILE * localfp = NULL;
i=0; j = 0;
__ReCeive:
FD_ZERO(&writefds);
tival.tv_sec = 10;
tival.tv_usec = 0;
if(sockfd > 0) FD_SET(sockfd, &writefds);
else {fprintf(stderr, "\n\tError, socket is negative!\n"); exit(0);}
ret = select(sockfd + 1, &writefds, NULL, NULL, &tival);
if(ret ==0 ) {
if(retry++ < 10) goto __ReCeive;
}
if(ret <= 0) {fprintf(stderr, "\n\tError while receiving!\n"); exit(0);}
if(FD_ISSET(sockfd, &writefds)) {
memset(buffer, 0, 1024);
memset(httpheader, 0, 1024);
if((localfp = fopen(NodeCurr->file, "w")) == NULL) {if(DEBUG) fprintf(stderr, "create file '%s' error\n", NodeCurr->file); return;}
/* receive data from web server */
while((nbytes=read(sockfd,buffer,1))==1)
{
if(i < 4) { /*获取HTTP消息头*/
if(buffer[0] == '\r' || buffer[0] == '\n') i++;
else i = 0;
memcpy(httpheader + j, buffer, 1); j++;
}
else { /*获取HTTP消息体*/
fprintf(localfp, "%c", buffer[0]); /* print content on the screen */
//fprintf(stdout, "%c", buffer[0]); /* print content on the screen */
i++;
}
}
fclose(localfp);
}
}
/**************************************************************功能：执行一次HTTP请求***************************************************************/
void DoOnce() { /* send and receive */
ConnectWeb(); /* connect to the web server */
/* send a request */
SendRequest();
/* receive a response message from web server */
ReceiveResponse();
close(sockfd); /* because HTTP protocol do something one connection, so I can close it after receiving */
}
/**************************************************************功能：执行HTTP请求***************************************************************/
void DoneWithList(int flag) {
if(flag) fprintf(stdout, "\tRequest.%d is:\n%s", ++reqn, request);
DoOnce();
if(flag) fprintf(stdout, "\n\tThe following is the response header:\n%s", httpheader);
}
/**************************************************************功能：从字符串src中分析出网站地址和端口，并得到文件和目录***************************************************************/
int GetHost(char * src, char ** web, char ** file, int * port, char ** dir) {
char * pA, * pB, * pC;
int len;
*port = 0;
if(!(*src)) return -1;
pA = src;
if(!strncmp(pA, "http://", strlen("http://"))) pA = src+strlen("http://");
/* else if(!strncmp(pA, "https://", strlen("https://"))) pA = src+strlen("https://"); */
else return 1;
pB = strchr(pA, '/');
if(pB) {
len = strlen(pA) - strlen(pB);
GetMemory(web, len);
memcpy((*web), pA, len);
if(*(pB+1)) {
Rstrchr(pB + 1, '/', &pC);
if(pC) len = strlen(pB + 1) - strlen(pC);
else len = 0;
if(len > 0) {
GetMemory(dir, len);
memcpy((*dir), pB + 1, len);
if(pC + 1) {
len = strlen(pC + 1);
GetMemory(file, len);
memcpy((*file), pC + 1, len);
}
else {
len = 1;
GetMemory(file, len);
memcpy((*file), e, len);
}
}
else {
len = 1;
GetMemory(dir, len);
memcpy((*dir), e + 1, len);
len = strlen(pB + 1);
GetMemory(file, len);
memcpy((*file), pB + 1, len);
}
}
else {
len = 1;
GetMemory(dir, len);
memcpy((*dir), e + 1, len);
len = 1;
GetMemory(file, len);
memcpy((*file), e, len);
}
}
else {
len = strlen(pA);
GetMemory(web, len);
memcpy((*web), pA, strlen(pA));
len = 1;
GetMemory(dir, len);
memcpy((*dir), e + 1, len);
len = 1;
GetMemory(file, len);
memcpy((*file), e, len);
}
pA = strchr((*web), ':');
if(pA) *port = atoi(pA + 1);
else *port = 80;
return 0;
}
/*********************************************************************
*filename: mailaddrsearch.c
*purpose:用C语言编写一个网络蜘蛛来搜索网上出现的电子邮件地址*tidied by: zhoulifa(zhoulifa@)周立发Linux知识传播者SOHO族开发者 最擅长C语言*date time:-08-31 21:00:00
*Note:任何人可以任意复制代码并运用这些文档，当然包括你的商业用途*但请遵循Linux公共服务技术支持中心*********************************************************************/
int main(int argc, char ** argv)
{
int WebPort;
char * WebHost = 0, * PageAddress = 0, * WebDir = 0;
if(argc < 2) {if(DEBUG) fprintf(stdout, "Command error, you should input like this:\n\t%s WebPageAddress1 WebPageAddress2 WebPageAddress3 ...", argv[0]); exit(0);}
NodeHeader = NodeTail = NodeCurr = 0;
//setlocale(LC_ALL, "zh_CN.gb2312");
for(i = 1; i < argc; i++) {
ret = GetHost(argv, &WebHost, &PageAddress, &WebPort, &WebDir); /* Get web page info */
if(ret) {if(DEBUG) fprintf(stdout, "GetHost error from '%s'\n", argv); exit(0);}
AddInitNode(WebHost, PageAddress, WebPort, WebDir); /* add this page to chain */
}
free(WebHost); free(PageAddress);free(WebDir);
if(DEBUG) {
fprintf(stdout, "\nDisplay.%5d:", FileNumber);
DisplayNode(NodeHeader); /* display every node */
}
HandleInitNode(NodeHeader); /* handle every page */
return 0;
}
/**************************************************************功能：分析网页***************************************************************/
void AnalyzePage(WEBNODE * node)
{
int fd;
int flength = 0;
fd = open(node->file, O_RDONLY);
if(fd == -1) goto __AnalyzeDone;
flength = lseek(fd, 1, SEEK_END);
write(fd, "\0", 1);
lseek(fd, 0, SEEK_SET);
mapped_mem = mmap(0, flength, PROT_READ, MAP_PRIVATE, fd, 0);
GetEmail(mapped_mem);
GetLink(mapped_mem);
close(fd);
munmap(mapped_mem, flength);
__AnalyzeDone:
close(fd);
node->IsHandled = 1;
remove(node->file);
}
/**************************************************************功能：为根节点设置兄弟节点***************************************************************/
void AddInitNode(char * Host, char * Page, int Port, char * Dir)
{
WEBNODE * NewNode;
char filename[MAXFILENAME + 1] = "";
if(NodeHeader == NULL) NewNode = NodeHeader = (WEBNODE *)malloc(sizeof(WEBNODE));
else NodeTail->brother = NewNode = (WEBNODE *)malloc(sizeof(WEBNODE));
memset(NewNode, 0, sizeof(WEBNODE));
NewNode->host = (char *)malloc(strlen(Host) + 1);
memset(NewNode->host, 0, strlen(Host) + 1);
NewNode->page = (char *)malloc(strlen(Page) + 1);
memset(NewNode->page, 0, strlen(Page) + 1);
NewNode->dir = (char *)malloc(strlen(Dir) + 1);
memset(NewNode->dir, 0, strlen(Dir) + 1);
NewNode->file = (char *)malloc(MAXFILENAME + 1);
memset(NewNode->file, 0, MAXFILENAME + 1);
strcpy(NewNode->host, Host);
strcpy(NewNode->page, Page);
strcpy(NewNode->dir, Dir);
sprintf(filename, "file%05d.html", FileNumber++);
strcpy(NewNode->file, filename);
NewNode->port = Port;
NewNode->IsHandled = 0;
NewNode->brother = 0;
NewNode->child = 0;
NodeTail = NewNode;
}
/**************************************************************功能：处理根节点信息***************************************************************/
void HandleInitNode(WEBNODE * node)
{
WEBNODE * CurrentNode = 0;
CurrentNode = node;
if(CurrentNode) {
while(CurrentNode) {
if(CurrentNode->IsHandled == 0) {
HandOneNode(CurrentNode);
if(DEBUG) {
fprintf(stdout, "\nDisplay.%5d:", FileNumber);
DisplayNode(NodeHeader); /* display every node */
}
}
CurrentNode = CurrentNode->brother;
}
CurrentNode = node;
while(CurrentNode) {
if(CurrentNode->child && CurrentNode->child->IsHandled == 0) {
HandleInitNode(CurrentNode->child);
}
CurrentNode = CurrentNode->brother;
}
}
}
/**************************************************************功能：显示年有节点信息***************************************************************/
void DisplayNode(WEBNODE * NodeHeader)
{
WEBNODE * TempNode;
TempNode = NodeHeader;
fprintf(stdout, "\n");
while(TempNode) {
if(!strcmp(TempNode->dir, "/")) fprintf(stdout, "\t%s:%d%s%s => %s %d\n", TempNode->host, TempNode->port, TempNode->dir, strcmp(TempNode->page, "@")?TempNode->page:"", TempNode->file, TempNode->IsHandled);
else fprintf(stdout, "\t%s:%d/%s/%s => %s %d\n", TempNode->host, TempNode->port, TempNode->dir, strcmp(TempNode->page, "@")?TempNode->page:"", TempNode->file, TempNode->IsHandled);
TempNode = TempNode->brother;
}
TempNode = NodeHeader;
while(TempNode) {
if(TempNode->child) DisplayNode(TempNode->child);
TempNode = TempNode->brother;
}
}
/**************************************************************功能：处理单个节点信息***************************************************************/
void HandOneNode(WEBNODE * node)
{
char UserAgent[1024] = "", Accept[1024] = "", AcceptLanguage[1024] = "", AcceptEncoding[1024] = "", AcceptCharset[1024] = "", KeepAlive[1024] = "", Connection[1024] = "", ContentType[1024] = "";
NodeCurr = node;
if((host=gethostbyname(NodeCurr->host))==NULL) /* get ip address by domain */
{
if(DEBUG) fprintf(stderr,"\tGethostname '%s' error, %s\n", NodeCurr->host, strerror(errno));
exit(1);
}
GetLocalAgent(UserAgent, Accept, AcceptLanguage, AcceptEncoding, AcceptCharset, KeepAlive, Connection, ContentType); /* Get client browser information */
if(strcmp(NodeCurr->dir, "/")) sprintf(request, "GET /%s/%s HTTP/1.0\r\nHost: %s\r\nUser-Agent: %s\r\nAccept: %s\r\nConnection: %s\r\n\r\n", NodeCurr->dir, strcmp(NodeCurr->page, "@")?NodeCurr->page:"", NodeCurr->host, UserAgent, Accept, Connection);
else sprintf(request, "GET %s%s HTTP/1.0\r\nHost: %s\r\nUser-Agent: %s\r\nAccept: %s\r\nConnection: %s\r\n\r\n", NodeCurr->dir, strcmp(NodeCurr->page, "@")?NodeCurr->page:"", NodeCurr->host, UserAgent, Accept, Connection);
DoneWithList(1);
AnalyzePage(NodeCurr);
}
/**************************************************************功能：从字符串src中分析出邮件地址保存到文件***************************************************************/
void GetEmail(char * src)
{
char * pa, * pb, * pc, *pd;
char myemail[1024] = "";
FILE * mailfp = NULL;
if((mailfp = fopen("email.txt", "a+")) == NULL) return;
pa = src;
while((pb = strchr(pa, '@'))) {
GetBeforePos(pb, &pc);
GetAfterPos(pb, &pd);
if(pc && pd && (strlen(pc) > (strlen(pd) + 3))) {
memset(myemail, 0, 1024);
memcpy(myemail, pc, strlen(pc) - strlen(pd));
if(strcmp(NodeCurr->dir, "/")) fprintf(mailfp, "%s\thttp://%s/%s/%s\n", myemail, NodeCurr->host, NodeCurr->dir, strcmp(NodeCurr->page, "@")?NodeCurr->page:"");
else fprintf(mailfp, "%s\thttp://%s%s%s\n", myemail, NodeCurr->host, NodeCurr->dir, strcmp(NodeCurr->page, "@")?NodeCurr->page:"");
if(*(pd + 1)) pa = pd + 1;
else break;
}
else if(*(pb + 1)) pa = pb + 1;
else break;
}
fclose(mailfp);
}
/**************************************************************功能：从src中找出前面的字母、数字等内含，即email地址中@的前面部分***************************************************************/
void GetBeforePos(char * src, char ** d)
{
char * x;
if(src - 1) x = src - 1;
else {*d = 0; return ;}
while(x) {
if(*x >= 'a' && *x <= 'z') {x--; continue;}
else if(*x >= 'A' && *x <= 'Z') {x--; continue;}
else if(*x >= '0' && *x <= '9') {x--; continue;}
else if(*x == '.' || *x == '-' || *x == '_') {x--; continue;}
else {break;}
}
x++;
if(x) *d = x;
else *d = 0;
}
/**************************************************************功能：从src中找出后面的字母、数字等内含，即email地址中@的后面部分***************************************************************/
void GetAfterPos(char * src, char ** d)
{
char * x;
if(src + 1) x = src + 1;
else {*d = 0; return ;}
while(x) {
if(*x >= 'a' && *x <= 'z') {x++; continue;}
else if(*x >= 'A' && *x <= 'Z') {x++; continue;}
else if(*x >= '0' && *x <= '9') {x++; continue;}
else if(*x == '.' || *x == '-' || *x == '_') {x++; continue;}
else {break;}
}
if(x) *d = x;
else *d = 0;
}
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