Web server implementation

C language is used to implement a simple web server. The program supports requests in html, css, js, jpg, and gif formats [cpp] # include <stdio. h> # include <fcntl. h> # include <netinet/in. h> # include <arpa/inet. h> # include <unistd. h> # include <sys/types. h> # include <sys/stat. h> # include <string. h> # include <stdlib. h> # define PORT 12345 # define WebRoot/home/meng/webpage/*** whether the string s1 ends with s2 */int endsWith (char s1 [], char s2 []) {int len1 = strlen (s1); int len2 = strlen (s2); int I = len1-1, j = len2-1; if (l En1 <len2) return 0; for (; I >=0 & j> = 0; I --, j --) {if (s1 [I]! = S2 [j]) return 0;} return 1;} int main () {int sockfd, fd, client; struct sockaddr_in addr; int len = sizeof (addr ); char recbuf [2048]; // socket connection if (sockfd = socket (AF_INET, SOCK_STREAM, 0) <0) {perror ("socket. \ n "); exit (1) ;}// set IP port bzero (& addr, sizeof (addr); addr. sin_family = AF_INET; addr. sin_port = htons (PORT); addr. sin_addr.s_addr = inet_addr ("127.0.0.1"); // bind if (bind (sockfd, (struct sockaddr *) & addr, si Zeof (addr) <0) {perror ("bind. \ n "); exit (1) ;}// maximum number of listen connections if (listen (sockfd, 10) <0) {perror (" listen. \ n "); exit (1);} printf (" listening... \ n "); while (1) {// obtain the client ID if (client = accept (sockfd, (struct sockaddr *) & addr, & len) <0) {perror ("accept. \ n "); exit (1) ;}// read Request Header int buf = 0; if (buf = read (client, recbuf, 2048)> = 0) {recbuf [buf] = '\ 0';} // printf ("% s \ n", recbuf); char * token = strtok (recbuf ,""); // obtain HT The middle part of the first line of the TP request, that is, URI if (token! = NULL) {token = strtok (NULL, "");} char type [256];/*** varies depending on the extension at the end of the requested resource, * different mine response types */if (endsWith (token ,". jpg ") {strcpy (type," image/jpeg \ r \ nAccept-Ranges: bytes ");} else if (endsWith (token ,". gif ") {strcpy (type," image/gif ");} else if (endsWith (token ,". js ") {strcpy (type," text/javascript ");} else if (endsWith (token ,". css ") {strcpy (type," text/css ");} else {strcpy (type," text/html ");} // read the file content char fi LePath [1024]; char content [2048*512]; int fileSize; strcpy (filePath, "/home/meng/webpage"); strcat (filePath, token ); fd = open (filePath, O_RDONLY, 0766); if (fd =-1) {strcpy (content, "Not Found");} else {fileSize = read (fd, content, sizeof (content); // printf ("% d \ n", strlen (content); content [fileSize] = '\ 0 '; if (fileSize <= 0) strcpy (content, "Not Found"); close (fd);} if (fileSize <= 0) {fileSize = strlen ("Not Found ");} Char sendBuf [2048*1024]; char tmp [20]; sprintf (tmp, "% d", fileSize); memset (sendBuf, '\ 0 ', sizeof (sendBuf); // returns the header information of the HTTP Response // all returned states are 200. Currently, other response states such as 404 are not judged. strcat (sendBuf, "HTTP/1.1 200 OK \ r \ n"); strcat (sendBuf, "Server: MENGXIANLU \ r \ n"); strcat (sendBuf, "Content-Length :"); strcat (sendBuf, tmp); strcat (sendBuf, "\ r \ n"); strcat (sendBuf, "Content-Type:"); strcat (sendBuf, type ); strcat (sendBuf, "\ r \ n ");// The following is extremely important, indicating the end Of the response header. // After the header ends, strcat (sendBuf, "\ r \ n") is included in the body;/** response header END */int I, j; /** response content (body) * // ** you cannot use strcat to connect strings. * // ** If an image is requested, its bytecode may contain '\ 0'. If strcat is used, information truncation may occur */for (I = 0, j = strlen (sendBuf); I <fileSize; I ++, j ++) {sendBuf [j] = content [I];} /** everything is ready */sendBuf [j] = '\ 0';/** the result is returned to the client */write (client, sendBuf, j ); close (client) ;}close (sockfd); return 0 ;}the following is a simple test performed from the browser after running the program.