一个web服务器的实现

一个web服务器的实现

客户端（浏览器）与web服务器之间的交互主要包含客户的请求和服务器的应答。
请求和应答的格式在超文本传输协议（HTTP）中有定义。HTTP协议使用纯文本。

例如：
$telnet  www.ouc.edu.cn  80
Trying 211.64.150.68...
Connected to www.ouc.edu.cn(211.64.150.68)
Escape character is '^]'.
GET /index.html HTTP/1.0

HTTP/1.1  200  OK
Date: Wed, 21 Jun 2006  08:26:04 GMT
Server: Apache/2.0.54(Unix) DAV/2
..................................

原理是telnet创建了一个socket并调用了connect来连接到web服务器。服务器
接受连接请求，并创建了一个基于socket的从客户端的键盘到web服务进程的数据通道。接下来，客户端输入请求：
GET /index.html HTTP/1.0

一个HTTP请求包含有3个字符串。第一个字符串是命令，第二个是参数，第三个是所用协议的版本号。  *注意还有一空行

web服务器读取请求，检查请求，然后返回一个请求。应答有两部分：头部和内容。头部以状态行起始，如下所示：

HTTP/1.1  200  ok

状态行含有两个或更多的字符串。第一个串是协议的版本，第二个串是返回码，这里是200，其文本解释是OK。头部的其余部分是关于应答的附加信息。
应答的其余部分是返回的具体内容。

下面这个webserv.c就是一个web服务器的具体实现。

编译程序，在某个端口运行它：
$gcc webserv.c  -o  webserv
$./webserv  12345
就可以访问web服务器，网址为http://yourhostname:12345/
将html文件放到该目录中并且用http://yourhostname:12345//filename.html就可以访问。

/* webserv.c - a web server
*    build: gcc webserv.c -o webserv
*/
#include <stdio.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netdb.h>
#include <sys/stat.h>
#include <time.h>
#include <string.h>

#define HOSTLEN  256
#define    BACKLOG  1

main(int ac, char *av[])
{
int sock, fd;
FILE *fpin;
char request[BUFSIZ];

if ( ac == 1 ){
fprintf(stderr,"usage: ws portnum\n");
exit(1);
}
sock = make_server_socket( atoi(av[1]) );
if ( sock == -1 ) exit(2);

/* main loop here */

while(1){
/* take a call and buffer it */
fd = accept( sock, NULL, NULL );
fpin = fdopen(fd, "r" );

/* read request */
fgets(request,BUFSIZ,fpin);
printf("got a call: request = %s", request);
read_til_crnl(fpin);

/* do what client asks */
process_rq(request, fd);

fclose(fpin);
}
}

/* ------------------------------------------------------ *
make_server_socket(int portnum)
创建一个服务器套接字,并调用listen监听
------------------------------------------------------ */

int make_server_socket(int portnum)
{
return make_server_socket_q(portnum, BACKLOG);
}
int make_server_socket_q(int portnum, int backlog)
{
struct  sockaddr_in saddr; /* build our address here */
struct hostent *hp; /* this is part of our */
char hostname[HOSTLEN];    /* address          */
int sock_id;          /* the socket          */

sock_id = socket(PF_INET, SOCK_STREAM, 0);  /* get a socket */
if ( sock_id == -1 )
return -1;

/** build address and bind it to socket **/

bzero((void *)&saddr, sizeof(saddr)); /* clear out struct    */
gethostname(hostname, HOSTLEN);       /* where am I ?       */
hp = gethostbyname(hostname);          /* get info about host  */
                                          /* fill in host part */
bcopy( (void *)hp->h_addr, (void *)&saddr.sin_addr, hp->h_length);
saddr.sin_port = htons(portnum);       /* fill in socket port  */
saddr.sin_family = AF_INET ;          /* fill in addr family  */
if ( bind(sock_id, (struct sockaddr *)&saddr, sizeof(saddr)) != 0 )
         return -1;

/** arrange for incoming calls **/

if ( listen(sock_id, backlog) != 0 )
return -1;
return sock_id;
}

/* ------------------------------------------------------ *
read_til_crnl(FILE *)
skip over all request info until a CRNL is seen
------------------------------------------------------ */

read_til_crnl(FILE *fp)
{
char buf[BUFSIZ];
while( fgets(buf,BUFSIZ,fp) != NULL && strcmp(buf,"\r\n") != 0 )
;
}

/* ------------------------------------------------------ *
process_rq( char *rq, int fd )
分析客户端的请求，分析然后做出相应的应答
rq is HTTP command:  GET /foo/bar.html HTTP/1.0
------------------------------------------------------ */

process_rq( char *rq, int fd )
{
char cmd[BUFSIZ], arg[BUFSIZ];

/* create a new process and return if not the child */
if ( fork() != 0 )
return;

strcpy(arg, "./"); /* precede args with ./ */
if ( sscanf(rq, "%s%s", cmd, arg+2) != 2 )
return;

if ( strcmp(cmd,"GET") != 0 )
cannot_do(fd);
else if ( not_exist( arg ) )
do_404(arg, fd );
else if ( isadir( arg ) )
do_ls( arg, fd );
else if ( ends_in_cgi( arg ) )
do_exec( arg, fd );
else
do_cat( arg, fd );
}

/* ------------------------------------------------------ *
the reply header thing: all functions need one
if content_type is NULL then don't send content type
------------------------------------------------------ */

header( FILE *fp, char *content_type )
{
fprintf(fp, "HTTP/1.0 200 OK\r\n");
if ( content_type )
fprintf(fp, "Content-type: %s\r\n", content_type );
}

/* ------------------------------------------------------ *
simple functions first:
      cannot_do(fd)    unimplemented HTTP command
and do_404(item,fd)    no such object
------------------------------------------------------ */

cannot_do(int fd)
{
FILE *fp = fdopen(fd,"w");

fprintf(fp, "HTTP/1.0 501 Not Implemented\r\n");
fprintf(fp, "Content-type: text/plain\r\n");
fprintf(fp, "\r\n");

fprintf(fp, "That command is not yet implemented\r\n");
fclose(fp);
}

do_404(char *item, int fd)
{
FILE *fp = fdopen(fd,"w");

fprintf(fp, "HTTP/1.0 404 Not Found\r\n");
fprintf(fp, "Content-type: text/plain\r\n");
fprintf(fp, "\r\n");

fprintf(fp, "The item you requested: %s\r\nis not found\r\n",
item);
fclose(fp);
}

/* ------------------------------------------------------ *
the directory listing section
isadir() uses stat, not_exist() uses stat
do_ls runs ls. It should not
------------------------------------------------------ */

isadir(char *f)
{
struct stat info;
return ( stat(f, &info) != -1 && S_ISDIR(info.st_mode) );
}

not_exist(char *f)
{
struct stat info;
return( stat(f,&info) == -1 );
}

do_ls(char *dir, int fd)
{
FILE *fp ;

fp = fdopen(fd,"w");
header(fp, "text/plain");
fprintf(fp,"\r\n");
fflush(fp);

dup2(fd,1);
dup2(fd,2);
close(fd);
execlp("ls","ls","-l",dir,NULL);
perror(dir);
exit(1);
}

/* ------------------------------------------------------ *
the cgi stuff.  function to check extension and
one to run the program.
------------------------------------------------------ */

char * file_type(char *f)
/* returns 'extension' of file */
{
char *cp;
if ( (cp = strrchr(f, '.' )) != NULL )
return cp+1;
return "";
}

ends_in_cgi(char *f)
{
return ( strcmp( file_type(f), "cgi" ) == 0 );
}

do_exec( char *prog, int fd )
{
FILE *fp ;

fp = fdopen(fd,"w");
header(fp, NULL);
fflush(fp);
dup2(fd, 1);
dup2(fd, 2);
close(fd);
execl(prog,prog,NULL);
perror(prog);
}
/* ------------------------------------------------------ *
do_cat(filename,fd)
sends back contents after a header
------------------------------------------------------ */

do_cat(char *f, int fd)
{
char *extension = file_type(f);
char *content = "text/plain";
FILE *fpsock, *fpfile;
int c;

if ( strcmp(extension,"html") == 0 )
content = "text/html";
else if ( strcmp(extension, "gif") == 0 )
content = "image/gif";
else if ( strcmp(extension, "jpg") == 0 )
content = "image/jpeg";
else if ( strcmp(extension, "jpeg") == 0 )
content = "image/jpeg";

fpsock = fdopen(fd, "w");
fpfile = fopen( f , "r");
if ( fpsock != NULL && fpfile != NULL )
{
header( fpsock, content );
fprintf(fpsock, "\r\n");
while( (c = getc(fpfile) ) != EOF )
putc(c, fpsock);
fclose(fpfile);
fclose(fpsock);
}
exit(0);
}

[ 本帖最后由 liuke432 于 2006-6-21 16:46 编辑 ]

er 回复于：2006-06-21 15:58:19

支持

kuaizaifeng 回复于：2006-06-21 16:12:56

好东东，支持

cmh_2003 回复于：2006-06-21 17:43:24

先顶下慢慢看~~~

HAMMER 回复于：2006-06-21 17:52:32

新到任的高手啊

linuxcici 回复于：2006-06-21 18:38:16

请问WEB服务器写的时候要注意点什么呢? 小弟正在学. ....好象很多书有关于这web server的code.

liuke432 回复于：2006-06-22 09:27:42

引用：原帖由 HAMMER 于 2006-6-21 17:52 发表
新到任的高手啊

多谢兄弟抬举，我还称不上是什么高手。：）
学习unix网络编程才半年多，看到有本书上的这个例子比较不错，
对于学习网络编程的朋友很有实践价值。于是就整理了一下，让大
家一起学习。

liuke432 回复于：2006-06-22 09:41:22

引用：原帖由 linuxcici 于 2006-6-21 18:38 发表
请问WEB服务器写的时候要注意点什么呢? 小弟正在学. ....好象很多书有关于这web server的code.

我对这个还不是很精通。 :(
web服务器的侧重点不一样，有的提供了更多的安全特征，有的则快速处理请求或使用较少的内存。
其中一个重要的特征是服务器的效率问题。服务器可以同时处理多少个请求？对于每个请求，服务器需要多少系统资源？
上面那个程序是用多进程来处理的。
下面再贴一个多线程的。

liuke432 回复于：2006-06-22 09:55:46

多线程的web服务器

多线程版本增加了内部统计功能：
   服务器的运行时间
   接收的客户端请求的数目
   发送回客户端的数据量

这里使用独立线程（Detached Threads）防止僵尸线程（Zombie Threads）

/* webserv_pthread.c - a threaded  web server
* building: gcc webserv_pthread.c -lpthread -o webserv_pthread
*/

#include <stdio.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netdb.h>
#include <sys/stat.h>
#include <string.h>

#include <pthread.h>
#include <stdlib.h>
#include <unistd.h>

#include <dirent.h>
#include <time.h>

#define HOSTLEN  256
#define    BACKLOG  1

/* server facts here */

time_t    server_started ;
int    server_bytes_sent;
int    server_requests;

main(int ac, char *av[])
{
int sock, fd;
int *fdptr;
pthread_t worker;
pthread_attr_t attr;

void *handle_call(void *);

if ( ac == 1 ){
fprintf(stderr,"usage: tws portnum\n");
exit(1);
}
sock = make_server_socket( atoi(av[1]) );
if ( sock == -1 ) { perror("making socket"); exit(2); }

setup(&attr);

/* main loop here: take call, handle call in new thread  */

while(1){
fd = accept( sock, NULL, NULL );
server_requests++;

fdptr = malloc(sizeof(int));
*fdptr = fd;
pthread_create(&worker,&attr,handle_call,fdptr);
}
}

/* ------------------------------------------------------ *
make_server_socket(int portnum)
创建一个服务器套接字,并调用listen监听
------------------------------------------------------ */

int make_server_socket_q(int , int );

int make_server_socket(int portnum)
{
return make_server_socket_q(portnum, BACKLOG);
}
int make_server_socket_q(int portnum, int backlog)
{
struct  sockaddr_in saddr; /* build our address here */
struct hostent *hp; /* this is part of our */
char hostname[HOSTLEN];    /* address          */
int sock_id;          /* the socket          */

sock_id = socket(PF_INET, SOCK_STREAM, 0);  /* get a socket */
if ( sock_id == -1 )
return -1;

/** build address and bind it to socket **/

bzero((void *)&saddr, sizeof(saddr)); /* clear out struct    */
gethostname(hostname, HOSTLEN);       /* where am I ?       */
hp = gethostbyname(hostname);          /* get info about host  */
                                          /* fill in host part */
bcopy( (void *)hp->h_addr, (void *)&saddr.sin_addr, hp->h_length);
saddr.sin_port = htons(portnum);       /* fill in socket port  */
saddr.sin_family = AF_INET ;          /* fill in addr family  */
if ( bind(sock_id, (struct sockaddr *)&saddr, sizeof(saddr)) != 0 )
         return -1;

/** arrange for incoming calls **/

if ( listen(sock_id, backlog) != 0 )
return -1;
return sock_id;
}

/*
* initialize the status variables and
* set the thread attribute to detached
*/
setup(pthread_attr_t *attrp)
{
pthread_attr_init(attrp);
pthread_attr_setdetachstate(attrp,PTHREAD_CREATE_DETACHED);

time(&server_started);
server_requests = 0;
server_bytes_sent = 0;
}

void *handle_call(void *fdptr)
{
FILE *fpin;
char request[BUFSIZ];
int fd ;

fd = *(int *)fdptr;
free(fdptr); /* get fd from arg  */

fpin = fdopen(fd, "r"); /* buffer input */
fgets(request,BUFSIZ,fpin); /* read client request */
printf("got a call on %d: request = %s", fd, request);
skip_rest_of_header(fpin);

process_rq(request, fd); /* process client rq */

fclose(fpin);
}

/* ------------------------------------------------------ *
skip_rest_of_header(FILE *)
skip over all request info until a CRNL is seen
------------------------------------------------------ */
skip_rest_of_header(FILE *fp)
{
char buf[BUFSIZ];
while( fgets(buf,BUFSIZ,fp) != NULL && strcmp(buf,"\r\n") != 0 )
;
}

/* ------------------------------------------------------ *
process_rq( char *rq, int fd )
do what the request asks for and write reply to fd
handles request in a new process
rq is HTTP command:  GET /foo/bar.html HTTP/1.0
------------------------------------------------------ */
process_rq( char *rq, int fd)
{
char cmd[BUFSIZ], arg[BUFSIZ];

if ( sscanf(rq, "%s%s", cmd, arg) != 2 )
return;
sanitize(arg);
printf("sanitized version is %s\n", arg);

if ( strcmp(cmd,"GET") != 0 )
not_implemented();
else if ( built_in(arg, fd) )
;
else if ( not_exist( arg ) )
do_404(arg, fd);
else if ( isadir( arg ) )
do_ls( arg, fd );
else
do_cat( arg, fd );
}
/*
* make sure all paths are below the current directory
*/
sanitize(char *str)
{
char *src, *dest;

src = dest = str;

while( *src ){
if( strncmp(src,"/../",4) == 0 )
src += 3;
else if ( strncmp(src,"//",2) == 0 )
src++;
else
*dest++ = *src++;
}
*dest = '\0';
if ( *str == '/' )
strcpy(str,str+1);

if ( str[0]=='\0' || strcmp(str,"./")==0 || strcmp(str,"./..")==0 )
strcpy(str,".");
}

/* handle built-in URLs here.  Only one so far is "status" */
built_in(char *arg, int fd)
{
FILE *fp;

if ( strcmp(arg,"status") != 0 )
return 0;
http_reply(fd, &fp, 200, "OK", "text/plain",NULL);

fprintf(fp,"Server started: %s", ctime(&server_started));
fprintf(fp,"Total requests: %d\n", server_requests);
fprintf(fp,"Bytes sent out: %d\n", server_bytes_sent);
fclose(fp);
return 1;
}

http_reply(int fd, FILE **fpp, int code, char *msg, char *type, char *content)
{
FILE *fp = fdopen(fd, "w");
int bytes = 0;

if ( fp != NULL ){
bytes = fprintf(fp,"HTTP/1.0 %d %s\r\n", code, msg);
bytes += fprintf(fp,"Content-type: %s\r\n\r\n", type);
if ( content )
bytes += fprintf(fp,"%s\r\n", content);
}
fflush(fp);
if ( fpp )
*fpp = fp;
else
fclose(fp);
return bytes;
}

/* ------------------------------------------------------ *
simple functions first:
      not_implemented(fd)    unimplemented HTTP command
      and do_404(item,fd)    no such object
------------------------------------------------------ */
not_implemented(int fd)
{
http_reply(fd,NULL,501,"Not Implemented","text/plain",
"That command is not implemented");
}

do_404(char *item, int fd)
{
http_reply(fd,NULL,404,"Not Found","text/plain",
"The item you seek is not here");
}

/* ------------------------------------------------------ *
the directory listing section
isadir() uses stat, not_exist() uses stat
------------------------------------------------------ */
isadir(char *f)
{
struct stat info;
return ( stat(f, &info) != -1 && S_ISDIR(info.st_mode) );
}

not_exist(char *f)
{
struct stat info;
return( stat(f,&info) == -1 );
}

do_ls(char *dir, int fd)
{
DIR       *dirptr;
struct dirent *direntp;
FILE       *fp;
int       bytes = 0;

bytes = http_reply(fd,&fp,200,"OK","text/plain",NULL);
bytes += fprintf(fp,"Listing of Directory %s\n", dir);

if ( (dirptr = opendir(dir)) != NULL ){
while( direntp = readdir(dirptr) ){
bytes += fprintf(fp, "%s\n", direntp->d_name);
}
closedir(dirptr);
}
fclose(fp);
server_bytes_sent += bytes;
}

/* ------------------------------------------------------ *
functions to cat files here.
file_type(filename) returns the 'extension': cat uses it
------------------------------------------------------ */
char * file_type(char *f)
{
char *cp;
if ( (cp = strrchr(f, '.' )) != NULL )
return cp+1;
return "";
}

/* do_cat(filename,fd): sends header then the contents */

do_cat(char *f, int fd)
{
char *extension = file_type(f);
char *type = "text/plain";
FILE *fpsock, *fpfile;
int c;
int bytes = 0;

if ( strcmp(extension,"html") == 0 )
type = "text/html";
else if ( strcmp(extension, "gif") == 0 )
type = "image/gif";
else if ( strcmp(extension, "jpg") == 0 )
type = "image/jpeg";
else if ( strcmp(extension, "jpeg") == 0 )
type = "image/jpeg";

fpsock = fdopen(fd, "w");
fpfile = fopen( f , "r");
if ( fpsock != NULL && fpfile != NULL )
{
bytes = http_reply(fd,&fpsock,200,"OK",type,NULL);
while( (c = getc(fpfile) ) != EOF ){
putc(c, fpsock);
bytes++;
}
fclose(fpfile);
fclose(fpsock);
}
server_bytes_sent += bytes;
}

作者: 逆雪寒发布时间: 2007-12-26

多线程的web服务器

多线程版本增加了内部统计功能：
   服务器的运行时间
   接收的客户端请求的数目
   发送回客户端的数据量

这里使用独立线程（Detached Threads）防止僵尸线程（Zombie Threads）

/* webserv_pthread.c - a threaded  web server
* building: gcc webserv_pthread.c -lpthread -o webserv_pthread
*/

#include <stdio.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netdb.h>
#include <sys/stat.h>
#include <string.h>

#include <pthread.h>
#include <stdlib.h>
#include <unistd.h>

#include <dirent.h>
#include <time.h>

#define HOSTLEN  256
#define    BACKLOG  1

/* server facts here */

time_t    server_started ;
int    server_bytes_sent;
int    server_requests;

main(int ac, char *av[])
{
int sock, fd;
int *fdptr;
pthread_t worker;
pthread_attr_t attr;

void *handle_call(void *);

if ( ac == 1 ){
fprintf(stderr,"usage: tws portnum\n");
exit(1);
}
sock = make_server_socket( atoi(av[1]) );
if ( sock == -1 ) { perror("making socket"); exit(2); }

setup(&attr);

/* main loop here: take call, handle call in new thread  */

while(1){
fd = accept( sock, NULL, NULL );
server_requests++;

fdptr = malloc(sizeof(int));
*fdptr = fd;
pthread_create(&worker,&attr,handle_call,fdptr);
}
}

/* ------------------------------------------------------ *
make_server_socket(int portnum)
创建一个服务器套接字,并调用listen监听
------------------------------------------------------ */

int make_server_socket_q(int , int );

int make_server_socket(int portnum)
{
return make_server_socket_q(portnum, BACKLOG);
}
int make_server_socket_q(int portnum, int backlog)
{
struct  sockaddr_in saddr; /* build our address here */
struct hostent *hp; /* this is part of our */
char hostname[HOSTLEN];    /* address          */
int sock_id;          /* the socket          */

sock_id = socket(PF_INET, SOCK_STREAM, 0);  /* get a socket */
if ( sock_id == -1 )
return -1;

/** build address and bind it to socket **/

bzero((void *)&saddr, sizeof(saddr)); /* clear out struct    */
gethostname(hostname, HOSTLEN);       /* where am I ?       */
hp = gethostbyname(hostname);          /* get info about host  */
                                          /* fill in host part */
bcopy( (void *)hp->h_addr, (void *)&saddr.sin_addr, hp->h_length);
saddr.sin_port = htons(portnum);       /* fill in socket port  */
saddr.sin_family = AF_INET ;          /* fill in addr family  */
if ( bind(sock_id, (struct sockaddr *)&saddr, sizeof(saddr)) != 0 )
         return -1;

/** arrange for incoming calls **/

if ( listen(sock_id, backlog) != 0 )
return -1;
return sock_id;
}

/*
* initialize the status variables and
* set the thread attribute to detached
*/
setup(pthread_attr_t *attrp)
{
pthread_attr_init(attrp);
pthread_attr_setdetachstate(attrp,PTHREAD_CREATE_DETACHED);

time(&server_started);
server_requests = 0;
server_bytes_sent = 0;
}

void *handle_call(void *fdptr)
{
FILE *fpin;
char request[BUFSIZ];
int fd ;

fd = *(int *)fdptr;
free(fdptr); /* get fd from arg  */

fpin = fdopen(fd, "r"); /* buffer input */
fgets(request,BUFSIZ,fpin); /* read client request */
printf("got a call on %d: request = %s", fd, request);
skip_rest_of_header(fpin);

process_rq(request, fd); /* process client rq */

fclose(fpin);
}

/* ------------------------------------------------------ *
skip_rest_of_header(FILE *)
skip over all request info until a CRNL is seen
------------------------------------------------------ */
skip_rest_of_header(FILE *fp)
{
char buf[BUFSIZ];
while( fgets(buf,BUFSIZ,fp) != NULL && strcmp(buf,"\r\n") != 0 )
;
}

/* ------------------------------------------------------ *
process_rq( char *rq, int fd )
do what the request asks for and write reply to fd
handles request in a new process
rq is HTTP command:  GET /foo/bar.html HTTP/1.0
------------------------------------------------------ */
process_rq( char *rq, int fd)
{
char cmd[BUFSIZ], arg[BUFSIZ];

if ( sscanf(rq, "%s%s", cmd, arg) != 2 )
return;
sanitize(arg);
printf("sanitized version is %s\n", arg);

if ( strcmp(cmd,"GET") != 0 )
not_implemented();
else if ( built_in(arg, fd) )
;
else if ( not_exist( arg ) )
do_404(arg, fd);
else if ( isadir( arg ) )
do_ls( arg, fd );
else
do_cat( arg, fd );
}
/*
* make sure all paths are below the current directory
*/
sanitize(char *str)
{
char *src, *dest;

src = dest = str;

while( *src ){
if( strncmp(src,"/../",4) == 0 )
src += 3;
else if ( strncmp(src,"//",2) == 0 )
src++;
else
*dest++ = *src++;
}
*dest = '\0';
if ( *str == '/' )
strcpy(str,str+1);

if ( str[0]=='\0' || strcmp(str,"./")==0 || strcmp(str,"./..")==0 )
strcpy(str,".");
}

/* handle built-in URLs here.  Only one so far is "status" */
built_in(char *arg, int fd)
{
FILE *fp;

if ( strcmp(arg,"status") != 0 )
return 0;
http_reply(fd, &fp, 200, "OK", "text/plain",NULL);

fprintf(fp,"Server started: %s", ctime(&server_started));
fprintf(fp,"Total requests: %d\n", server_requests);
fprintf(fp,"Bytes sent out: %d\n", server_bytes_sent);
fclose(fp);
return 1;
}

http_reply(int fd, FILE **fpp, int code, char *msg, char *type, char *content)
{
FILE *fp = fdopen(fd, "w");
int bytes = 0;

if ( fp != NULL ){
bytes = fprintf(fp,"HTTP/1.0 %d %s\r\n", code, msg);
bytes += fprintf(fp,"Content-type: %s\r\n\r\n", type);
if ( content )
bytes += fprintf(fp,"%s\r\n", content);
}
fflush(fp);
if ( fpp )
*fpp = fp;
else
fclose(fp);
return bytes;
}

/* ------------------------------------------------------ *
simple functions first:
      not_implemented(fd)    unimplemented HTTP command
      and do_404(item,fd)    no such object
------------------------------------------------------ */
not_implemented(int fd)
{
http_reply(fd,NULL,501,"Not Implemented","text/plain",
"That command is not implemented");
}

do_404(char *item, int fd)
{
http_reply(fd,NULL,404,"Not Found","text/plain",
"The item you seek is not here");
}

/* ------------------------------------------------------ *
the directory listing section
isadir() uses stat, not_exist() uses stat
------------------------------------------------------ */
isadir(char *f)
{
struct stat info;
return ( stat(f, &info) != -1 && S_ISDIR(info.st_mode) );
}

not_exist(char *f)
{
struct stat info;
return( stat(f,&info) == -1 );
}

do_ls(char *dir, int fd)
{
DIR       *dirptr;
struct dirent *direntp;
FILE       *fp;
int       bytes = 0;

bytes = http_reply(fd,&fp,200,"OK","text/plain",NULL);
bytes += fprintf(fp,"Listing of Directory %s\n", dir);

if ( (dirptr = opendir(dir)) != NULL ){
while( direntp = readdir(dirptr) ){
bytes += fprintf(fp, "%s\n", direntp->d_name);
}
closedir(dirptr);
}
fclose(fp);
server_bytes_sent += bytes;
}

/* ------------------------------------------------------ *
functions to cat files here.
file_type(filename) returns the 'extension': cat uses it
------------------------------------------------------ */
char * file_type(char *f)
{
char *cp;
if ( (cp = strrchr(f, '.' )) != NULL )
return cp+1;
return "";
}

/* do_cat(filename,fd): sends header then the contents */

do_cat(char *f, int fd)
{
char *extension = file_type(f);
char *type = "text/plain";
FILE *fpsock, *fpfile;
int c;
int bytes = 0;

if ( strcmp(extension,"html") == 0 )
type = "text/html";
else if ( strcmp(extension, "gif") == 0 )
type = "image/gif";
else if ( strcmp(extension, "jpg") == 0 )
type = "image/jpeg";
else if ( strcmp(extension, "jpeg") == 0 )
type = "image/jpeg";

fpsock = fdopen(fd, "w");
fpfile = fopen( f , "r");
if ( fpsock != NULL && fpfile != NULL )
{
bytes = http_reply(fd,&fpsock,200,"OK",type,NULL);
while( (c = getc(fpfile) ) != EOF ){
putc(c, fpsock);
bytes++;
}
fclose(fpfile);
fclose(fpsock);
}
server_bytes_sent += bytes;
}

作者: 逆雪寒发布时间: 2007-12-26

楼主汗啊!~~~

作者: forest 发布时间: 2007-12-26

嗯，还是不错的说。