利用xinetd實現簡單web伺服器（映象站）
阿新 • • 發佈：2019-02-13
瀏覽效果：
linux伺服器安裝xinetd後，在/etc/xinetd.d/目錄下建立xhttpd檔案，並輸入內容：
service xhttpd
{
socket_type = stream
protocol = tcp
wait = no
user = gongluck
server = /home/gongluck/桌面/xhttpd
server_args = /home/gongluck/桌面/xhttpdir
disable = no
flags = IPv4
}重啟服務：xhttpd 9527/tcp # xhttpd service xhttpd 9527/udp # xhttpd servic
sudo service xinetd restart由於xinetd會幫助我們與瀏覽器建立好連線，並且將stdin重定向到瀏覽器的傳送端，stdout重定向到瀏覽器的接收端。所以xhttpd程式只需要從標準輸入中讀取瀏覽器的請求資料，把響應資料寫入標準輸出中即可。#include <stdio.h> #include <stdlib.h> #include <string.h> #include <unistd.h> #include <sys/types.h> #include <sys/stat.h> #include <fcntl.h> #include <ctype.h> #include <dirent.h> #define LEN 4096 char* get_filetype(const char* file); void send_error(int status,char* title); void send_header(int status,char* title, char* filetype); void decode(char* to, char* from); void encode(char* to, char* from); int main(int argc,const char* argv[]) { if(argc < 2) send_error(500,"server error : argc < 2"); //if(access(argv[1],R_OK | F_OK) != 0) if(chdir(argv[1]) < 0) send_error(500,"server error : chdir error"); char line[LEN],type[LEN],path[LEN],protocol[LEN]; if(fgets(line,sizeof(line),stdin) == NULL) send_error(500,"server error : type path protocol"); if(sscanf(line,"%[^ ] %[^ ] %[^ ]",type,path,protocol) != 3) send_error(400,"bad request"); if(strcasecmp(type,"GET") != 0) send_error(400,"method not allow"); if(path[0] != '/') send_error(404,"file not found"); while(fgets(line,sizeof(line),stdin) != NULL) { if(strcmp(line,"\n") == 0 || strcmp(line,"\r\n") == 0) break; } char file[LEN]; struct stat st; file[0] = '.'; decode(file+1,path); //printf("%s\n",&path[1]); //printf("%s\n",file); if(stat(file,&st) < 0) { printf("file : %s\r\n",file); send_error(500,"server error : stat"); } if(S_ISDIR(st.st_mode)) { send_header(200,"OK","text/html;charset=utf-8"); printf("<html>" "<head><title>Index of %s</title></head>" "<body bgcolor=\"#cc99cc\">" "<h4>Index of %s</h4>" "<pre>" ,file,file); struct dirent** dl; int nf = scandir(file,&dl,NULL,alphasort); if(nf < 0) perror("scandir"); else { struct stat fst; char stfile[LEN]; for(int i=0;i<nf; ++i) { strcpy(stfile,file); strcat(stfile,"/"); strcat(stfile,dl[i]->d_name); if(lstat(stfile,&fst) < 0) printf("<a href=\"%s%s/\">%-32.32s/</a>",file+1,dl[i]->d_name,dl[i]->d_name); else if(S_ISDIR(fst.st_mode)) printf("<a href=\"%s%s/\">%-32.32s/</a> \t\t%14lld",file+1,dl[i]->d_name,dl[i]->d_name,(long long)fst.st_size); else printf("<a href=\"%s%s\">%-32.32s</a> \t\t%14lld",file+1,dl[i]->d_name,dl[i]->d_name,(long long)fst.st_size); printf("<br/>"); } } printf("</pre>" "</body>" "</html>"); } else { //普通檔案 FILE* fp = fopen(file,"r"); if(fp == NULL) send_error(500,"server error : open file"); send_header(200,"send header",get_filetype(file)); int ch;//這裡必須用int判斷EOF，我真是菜雞。 while((ch = getc(fp)) != EOF) { putchar(ch); } fflush(stdout); fclose(fp); fp = NULL; } // printf("test success !\n"); return 0; } int hex2d(char hex) { if(hex >= '0' && hex <= '9') return hex-'0'; else if(hex >= 'a' && hex <= 'f') return hex-'a'+10; else if(hex >= 'A' && hex <= 'F') return hex-'A'+10; else return hex; } void decode(char* to, char* from) { if(to == NULL || from == NULL) return; while(*from != '\0') { if(from[0] == '%' && isxdigit(from[1]) && isxdigit(from[2])) { *to = hex2d(from[1])*16 + hex2d(from[2]); from += 3; } else { *to = *from; ++from; } ++to; } *to = '\0'; } void encode(char* to, char* from) { if(to == NULL && from == NULL) return; while(*from != '\0') { if(isalnum(*from) || strchr("/._-~",*from) != NULL) { *to = *from; ++to; ++from; } else { sprintf(to,"%%%02x",*from); to += 3; from += 3; } } *to = '\0'; } char* get_filetype(const char* file) { if(file == NULL) return NULL; char* dot = strrchr(file,'.'); if(*dot == '\0') return "text/plain; charset=utf-8"; else if(strcmp(dot,".html") == 0) return "text/html; charset=utf-8"; else if(strcmp(dot, ".jpg") == 0) return "image/jpeg"; else if(strcmp(dot, ".gif") == 0) return "image/gif"; else if(strcmp(dot, ".png") == 0) return "image/png"; else if(strcmp(dot, ".wav") == 0) return "audio/wav"; else if(strcmp(dot, ".avi") == 0) return "video/x-msvideo"; else if(strcmp(dot, ".mov") == 0) return "video/quicktime"; else if(strcmp(dot, ".mp3") == 0) return "audio/mpeg"; else return "text/plain; charset=utf-8"; } void send_header(int status, char* title, char* filetype) { if(title == NULL || filetype == NULL) { title = "ERROR"; filetype = "text/plain; charset=utf-8"; } printf("HTTP/1.1 %d %s\r\n",status,title); printf("Content-Type:%s\r\n",filetype); printf("\r\n"); } void send_error(int status,char* title) { if(title == NULL) title = "ERROR"; send_header(status,title,"text/html; charset=utf-8"); printf("<html>\n" "<head><title>%d %s</title></head>\n" "<body bgcolor=\"#cc99cc\">\n" "<h4>error!</h4>\n" "<hr>\n" "<address>\n" "<a href=\"http://blog.csdn.net/gongluck93/\">gongluck</a>\n" "</address>\n" "</body>\n" "</html>", status,title); fflush(stdout); exit(1); }
這裡只是用http協議的很簡單的一部分：
GET /請求的檔名 HTTP/1.1HTTP/1.1 狀態碼 描述
Content-Type:回傳檔案型別
\r\n
回傳檔案資料