linux服务器安装xinetd后，在/etc/xinetd.d/目录下创建xhttpd文件，并输入内容：
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
}
然后在/etc/services文件的最后添加自己使用的端口和进程的名字：
xhttpd 9527/tcp # xhttpd service
xhttpd 9527/udp # xhttpd servic
重启服务：
sudo service xinetd restart
xhttpd程序的代码：
#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,"
") == 0 || strcmp(line,"
") == 0)
break;
}
char file[LEN];
struct stat st;
file[0] = '.';
decode(file+1,path);
//printf("%s
",&path[1]);
//printf("%s
",file);
if(stat(file,&st) < 0)
{
printf("file : %s
",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> %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> %14lld",file+1,dl[i]->d_name,dl[i]->d_name,(long long)fst.st_size);
printf("<br/>");
}
}
printf("</pre>"
"</body>"
"</html>");
}
else
{
//普通文件
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;//这里必须用int判断EOF，我真是菜鸡。
while((ch = getc(fp)) != EOF)
{
putchar(ch);
}
fflush(stdout);
fclose(fp);
fp = NULL;
}
// printf("test success !
");
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 != ' ')
{
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 = ' ';
}
void encode(char* to, char* from)
{
if(to == NULL && from == NULL)
return;
while(*from != ' ')
{
if(isalnum(*from) || strchr("/._-~",*from) != NULL)
{
*to = *from;
++to;
++from;
}
else
{
sprintf(to,"%%%02x",*from);
to += 3;
from += 3;
}
}
*to = ' ';
}
char* get_filetype(const char* file)
{
if(file == NULL)
return NULL;
char* dot = strrchr(file,'.');
if(*dot == ' ')
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
",status,title);
printf("Content-Type:%s
",filetype);
printf("
");
}
void send_error(int status,char* title)
{
if(title == NULL)
title = "ERROR";
send_header(status,title,"text/html; charset=utf-8");
printf("<html>
"
"<head><title>%d %s</title></head>
"
"<body bgcolor="#cc99cc">
"
"<h4>error!</h4>
"
"<hr>
"
"<address>
"
"<a href="http://localhost/">localhost</a>
"
"</address>
"
"</body>
"
"</html>",
status,title);
fflush(stdout);
exit(1);
}
由于xinetd会帮助我们与浏览器建立好连接，并且将stdin重定向到浏览器的发送端，stdout重定向到浏览器的接收端。所以xhttpd程序只需要从标准输入中读取浏览器的请求数据，把响应数据写入标准输出中即可。
这里只是用http协议的很简单的一部分：
GET /请求的文件名 HTTP/1.1
HTTP/1.1 状态码 描述
Content-Type:回传文件类型
回传文件数据