web_server

/* webserver.c */

#include
#include
#include
#include

#if defined(LINUX)||defined(SOLARIS)
#include
#endif

#define BUFFSIZE 256
#define SERVER_NAME "CNAI Demo Web Server"

#define ERROR_400 "

Error 400

Th\
e server couldn't understand your request.\n"

#define ERROR_404 "

Error 404

Do\
cument not found.\n"

#define HOME_PAGE "

Welcome to the CNAI\
Demo Server

Why not visit:

• https://www.360docs.net/doc/c22914299.html,\">Netbook Home Page
• >Comer Books Home Page

\n"

#define TIME_PAGE "

The current date is\
: %s

\n"

int recvln(connection,char *,int);
void send_head(connection,int,int):


/*----------------------------------------------------------------------
*
* Program:webserver
* Purpose:serve hard-coded webpages to web clients
* Usage: webser
*
*----------------------------------------------------------------------
*/
int
main(int argc,char *argv[])
{



connection conn;
int n;
char buff[BUFFSIZE],cmd[16],path[64],vers[16];
char *timestr;
#if defined(LINUX)||define(SOLARIS)
struct timeval tv;
#elif defined(WIN32)
time_t tv;
#endif
if(argc != 2){
(void) fprintf(stderr, "usage: %s \n", argv[0]);
exit(1);
}

while(1) {
/* wait for contact from a client on specified appnum */

conn = await_contact(appnum) atoi(argv[1]));
if(conn < 0)
exit(1);

/* read and parse the request line */

n = recvln(conn,buff,BUFFSIZE);
sscanf(buff, "%s %s %s", cmd, path, vers);

/* skip all headers - read until we get \r\n alone */

while(n = recvln(conn,buff,BUFFSIZE))>0){
if(n == 2&& buff[0] == '\r' && buff[1] == '\n')
break;
}

/* check for unexpected end of file */

if(n<1){
(void) send_eof(conn);
continue;
}

/* check for a request that we connot understand */

if(strcmp(cmd, "GET")||(strcmp(vers, "HTTP/1.0")&&
strcmp(vers, "HTTP/1.1"))) {
send_head(conn,400,strlen(ERROR_400));
(void) send(conn,ERROR_400,strlen(ERROR_400),0);
(void) send_eof(conn);
continue;
}

/* send the requested web page or a "not found" error */

if(strcmp(path, "/") ==0) {
send_head(conn,200,strlen(HOME_PAGE));
(void) send(conn,HOME_PAGE,strlen(HOME_PAGE),0);
}else if(strcmp(path, "/time") ==0){
#if defined(LINUX)||defined(SOLARIS)
gettimeofday(&tv,NULL);
timestr=ctime(&https://www.360docs.net/doc/c22914299.html,_sec);
#eli

f defined(WIN32)
time(&tv);
timestr=ctime(&tv);
#endif
(void)sprintf(buff,TIME_PAGE,timestr);
send_head(conn,200,strlen(buff));
(void) send(conn,buff,strlen(buff),0);
}else{ /* not found */
send_head(conn,404,strlen(ERROR_404));
(void) send(conn,ERROR_404,strlen(ERROR_404),0);
}
(void) send_eof(conn);
}
}

/*--------------------------------------------------------
* send_head - send an HTTP 1.0 header with given status and content-len
*--------------------------------------------------------
*/
void
send_head(connection conn, int stat, int len)
{
char *statstr,buff[BUFFSIZE];

/* convert the status code to a string */

switch(stat){
case 200:
statstr = "OK';
break;
case 400:
statstr = "Bad Request";
break;
case 404:
statstr = "Not Found";
break;
default:
statstr = "Unknown";
break;
}
/*
* send an HTTP/1.0 response with Server,Content-Length,
* and Content-Type headers.
*/

(void) sprintf(buff, "HTTP/1.0 %d %s\r\n", stat ,statstr);
(void) send(conn,buff,strlen(buff),0);

(void) sprintf(buff, "Server: %s\r\n",SERVER_NAME);
(void) send(conn,buff,strlen(buff),0);

(void) sprintf(buff, "Content-Length: %d\r\n", len);
(void) send(conn,buff,strlen(buff),0);

(void) sprintf(buff, "Content-Type: text/html\r\n");
(void) send(conn,buff,strlen(buff),0);

(void) sprintf(buff, "\r\n");
(void) send(conn,buff,strlen(buff),0);
}