Max's Blog

in man rm…..

       To remove a file whose name starts with a ‘-’, for example ‘-foo’, use one of these commands:

              rm — -foo

              rm ./-foo

翻代码翻出n年前写的东西，当初还想做个tracker的，还去sourceforge申请个项目，没通过。。。怀念一下：

import java.util.*;

public class BitDecoder
{
 //0
 public static final byte ZERO_BYTE = 0x30;
 
 //9
 public static final byte NINE_BYTE = 0x39;
 
 //-
 public static final byte MINUS_BYTE = 0x2D;
 
 //:
 public static final byte COLON_BYTE = 0x3A;
 
 //d
 public static final byte d_BYTE = 0x64;
 
 //e
 public static final byte e_BYTE = 0x65;
 
 //i
 public static final byte i_BYTE = 0x69;
 
 //l
 public static final byte l_BYTE = 0x6c;
 
 //n
 public static final byte NULL_BYTE = 0x6e;
 
 //最大解释层数
 public static int MAX_LAYER = 8;
 
 private int now_layer = 0;
 private String index_key = “”;
 private int key_start = 0;
 private int key_end = 0;
 
 public BitDecoder(String key)
 {
  if(key!=null)
   index_key = key;
 }
 
 public void reset(String key)
 {
  now_layer = 0;
  key_start = 0;
  key_end = 0;
  if(key!=null)
   index_key = key;
  else
   index_key = “”;
 }
 
 public String getkey()
 {
  return index_key;
 }
 
 public int getKeyStart()
 {
  return key_start;
 }
 
 public int getKeyEnd()
 {
  return key_end;
 }
 
 //解出int，用String保存
 private BTDecodeObj decode_int(byte [] bytes,int index) throws Exception
 {
  int till_index = ++index;
  
  byte workingbyte = bytes[till_index];
  
  if(workingbyte == MINUS_BYTE)
  {
   workingbyte = bytes[till_index+1];
   if(workingbyte == ZERO_BYTE)
    throw new Exception(“number -0 is not allowed”);
   else if(workingbyte == e_BYTE)
    throw new Exception(“only minus is not allowed”);
   else if(workingbyte>NINE_BYTE || workingbyte<ZERO_BYTE)
    throw new Exception(“number must be 0-9”);
   else
    till_index++;
  }
  
  while(true)
  {
   workingbyte = bytes[till_index];
   if(workingbyte == e_BYTE)
    break;
   else if(workingbyte>NINE_BYTE || workingbyte<ZERO_BYTE)
    throw new Exception(“number must be 0-9”);
   else
    till_index++;
  }
  
  if(bytes[index]==ZERO_BYTE && till_index!=index+1)
   throw new Exception(“number 0 must be alone”);
  else  
   return new BTDecodeObj(new String(bytes,index,till_index-index),till_index+1);
 }
 
 //解出String
 private BTDecodeObj decode_string(byte [] bytes,int index) throws Exception
 {
  int colon_index = index;
  byte workingbyte = 0x00;
  while(true)
  {
   workingbyte = bytes[colon_index];
   if(workingbyte == COLON_BYTE)
    break;
   else if(workingbyte>NINE_BYTE || workingbyte<ZERO_BYTE)
    throw new Exception(“string length must be 0-9”);
   else
    colon_index++;
  }
  
  if(bytes[index] == ZERO_BYTE && colon_index!=index+1)
   throw new Exception(“string length 0 must follow by :”);
  
  index = Integer.parseInt(new String(bytes,index,colon_index-index));
  colon_index++;

  return new BTDecodeObj(new String(bytes,colon_index,index,”8859_1″),colon_index+index);
 }
 
 //解出List
 private BTDecodeObj decode_list(byte [] bytes,int index) throws Exception
 {
  now_layer++;
  if(now_layer > MAX_LAYER)
   throw new Exception(“too many list or dictionary layer!”);
  
  index++;
  ArrayList resultlist = new ArrayList();
  
  BTDecodeObj tempobj = null;
  
  while(bytes[index] != e_BYTE)
  {
   tempobj = bdecode(bytes,index);
   index = tempobj.getIndex();
   resultlist.add(tempobj.getObj());
  }
  
  now_layer–;
  return new BTDecodeObj(resultlist,index+1);
 }
 
 //解出dict
 private BTDecodeObj decode_dict(byte [] bytes,int index) throws Exception
 {
  now_layer++;
  if(now_layer > MAX_LAYER)
   throw new Exception(“too many list or dictionary layer!”);
  
  index++;
  HashMap resultmap =  new HashMap();
  
  BTDecodeObj tempobj = null;
  String lastkey = “”;
  String nowkey = null;
  
  while(bytes[index] != e_BYTE)
  {
   tempobj = decode_string(bytes,index);
   nowkey = (String)tempobj.getObj();
   if(nowkey.compareTo(lastkey) <= 0)
    throw new Exception(“dictionary lexicographically order error!”);
   
   lastkey = nowkey;
   index = tempobj.getIndex();
   if(key_start==0 && index_key.equals(lastkey))
   {
    key_start = index;
   }
   
   tempobj = bdecode(bytes,index);
   index = tempobj.getIndex();
   if(key_start!=0 && index_key.equals(lastkey))
   {
    key_end = index;
   }
   
   resultmap.put(nowkey,tempobj.getObj());
  }
  
  now_layer–;
  return new BTDecodeObj(resultmap,index+1);
 }
 
 private BTDecodeObj bdecode(byte [] bytes,int index) throws Exception
 {
  if(bytes[index]>=ZERO_BYTE && bytes[index]<=NINE_BYTE)
   return decode_string(bytes,index);
  else if(bytes[index] == d_BYTE)
   return decode_dict(bytes,index);
  else if(bytes[index] == l_BYTE)
   return decode_list(bytes,index);
  else if(bytes[index] == i_BYTE)
   return decode_int(bytes,index);
  else
   throw new Exception(“torrent bencode format error!”);
 }
 
 public Object bdecode(byte [] bytes) throws Exception
 {
  BTDecodeObj resultobj = bdecode(bytes,0);
  if(resultobj.getIndex() != bytes.length)
   throw new Exception(“torrent bencode format error,length exception!”);
  
  return resultobj.getObj();
 }
 
 public int getNowLayer()
 {
  return now_layer;
 }

 public static class BTDecodeObj
{
 Object obj = null;
 int index = 0;
 
 public BTDecodeObj(Object obj,int index)
 {
  this.obj = obj;
  this.index = index;
 }
 
 public Object getObj()
 {
  return obj;
 }
 
 public int getIndex()
 {
  return index;
 }
}
}

n年前的课题了，今天要用，都忘记了，记录一下

byte to hex 直接java方法：

// convert a single byte b to a 2-char hex string

// with possible leading zero.

String s2 = Integer.toString( ( b & 0xff ) + 0x100, 16 /* radix */ )

		.substring( 1 );

字典法和反向转换，记录自己在无线时候写的一个：

        /*
         *取得byte的16进制字符串
        */     
        private static final String HexString = “0123456789ABCDEF”;
       

        public static String getHexString(byte [] msg_byte)
        {
                StringBuffer sb = new StringBuffer(msg_byte.length * 2);
                for(int i =0;i<msg_byte.length;i++)
                {
                        sb.append(HexString.charAt(0xf&msg_byte[i]>>4)).append(HexString.charAt(msg_byte[i]&0xf));
                }
                return sb.toString();
        }      
               
        public static byte[] getBytesFromHexStr(String s)
        {              
                try    
                {              
                        int i = s.length();
                        byte result[] = new byte[i >> 1];
                        for(int k = 0; k < i;)
                                result[k >> 1] = (byte)(Integer.parseInt(s.substring(k,k+=2),16));
                        return result;
                }
                catch(Exception ex)
                {
                        //ex.printStackTrace();
                        return null;
                }
        }

这几天mima的机器经常死，看了一下apache的log，发现很多::1的请求

 ::1 – – [13/Mar/2008:23:59:02 +0800] “GET /” 400 460 “-” “-”

看不懂，到apache 的userlist里面问了一下，原来是::1是ipv6的本机表示，真实out了，ipv6都不知道。。。

然后就用tcpdump看了一下

tcpdump -A -s0 -i any tcp src host ::1

发现了请求内容，原来是。。。Apache internal dummy connection。。。汗啊汗，开头我还以为linux中木马了。。。

google了一下，官方没有找到什么说明，找到一个blog有写一点

http://vdachev.net/blog/2007/02/01/apache-internal-dummy-connection/ 

I Google’d for “(internal dummy connection)”. There were only a few results explaining what was really happening… many of them were rumors. I found an entry in Yenya’s blog with the same issue. It suggested this is a replacement in Apache 2.x of sending signals to its processes as signals are not available on all platforms. This means during graceful restart, instead a SIGUSR1 to be sent to all child processes, a subrequest is made. The CodeSearch results seem to confirm this. Now, let’s say my server is running ~100 processes and I change anything in my configuration. Would this mean ~100 subrequest at a time ? Yeah, this would be an overhead (over- an already loaded server’s -head) ! Oh, my web servers is being gracefully reloaded each time a log is rotated… ~50 times.  

It seems this feature exists in the whole 2.x series so a downgrade to 2.0 would not solve this issue. It’s just in versions prior to 2.2.0 there was no indication of such internal requests. Some people proposed switching to Worker MPM. However people say that on 2.6.x boxes (my case) Prefork MPM runs faster. Additionally, PHP is not thread-safe by default (the Worker MPM is thread based) and it should be compiled with Zend Thread Safety libraries (–enable-experimental-zts). I don’t think it’s worth… It would be great if there was a way to switch back to the old behaviour on platforms that support it… it’s odd otherwise. Now I’ve disabled the logging for the default website and I’ve left mod_redirect (as I don’t think Apache would follow redirects internally).

P.S.: I suppose signals are also used to terminate a child then the number of request reaches MaxRequestsPerChild, so I experimentaly disabled this limit as it’s used to protect the system from any memory leaks in child processes. However, I haven’t noticed any by now. I hope this will decrease the number of signals sent to the child processes. Let’s check this out…

大概就是一种新的内部通信机制，代替了发进程信号，好像是2.0就开始有了，但是2.2没有从log中过滤，不知道有什么影响，在官方的buglist上面看到好像2.2.6有点问题，tmd服务器刚好就是2.2.6，下周顺便升级了丫的。。。

昨晚小汪子过来，看见偶统计ip的程序，说。。。其实一行就可以做到了。。。

cat access_log|awk ‘{print $1}’|sort |uniq -c|sort -nr

 狂晕ing，对linux命令还是不熟悉啊。。。

今天mima的tomcat又挂掉了，写一段够短的程序分析一下独立ip数量。。。

本来用sed写，写到一半好像写不下去了。。。

cat access_log | sed “s/ – – .*//”  |sort |????

然后用perl写了一个

perl countip.pl access_log |head

countip.pl

#!/usr/bin/perl
while(<>){
                chomp();
                $_ =~ s/ – – .+//g;
                $count{$_}++;
}
foreach $word (sort by_count keys %count){
        print “$word occurs $count{$word} times\n”;
}
sub by_count {
        $count{$b} <=> $count{$a}
}

sort使用了一个子例程作参数来定义排序规则

昨天写发送邮件的时候用了spring一个property loader，今天发现所有struts2的页面都返回input validation错误了。。。查了半天，查到fielderror是某个mail的properties，为啥struts2回去读那个properties呢。。。原来是spring loader惹的祸。。。

  <bean id=”MailProperties” class=”org.springframework.beans.factory.config.PropertiesFactoryBean”>
  <property name=”location”>
  <value>/WEB-INF/classes/pwrl.mail.properties</value>
  </property>
 </bean>

 就是这个PropertiesFactoryBean的东东，和struts2的 org.apache.struts2.interceptor.validation.AnnotationValidationInterceptor 存在一些数据共享关系，再详细看看源代码才知道。。。

今天写个后台发送，连到smtp要登录的，我见java mail里面api默认就可以在connect的时候输入密码，以为直接用就可以啦，谁知道sun 的smtp实现default不打开auth，google一下，记录一些文档。。。还搜到某个猪头说session参数就只有一开始那几个，其实可以有很多很多的。。。

明天回去还要加上 msg.saveChanges();  不知道有啥用。。。

好像是保存message状态和header的，The send method calls the saveChanges method on the message before sending it.  看来不用改了。。。

Package com.sun.mail.smtp Description

An SMTP protocol provider for the JavaMail API that provides access to an SMTP server. Refer to RFC 821 for more information.

When sending a message, detailed information on each address that fails is available in an SMTPAddressFailedException chained off the top level SendFailedException that is thrown. In addition, if the mail.smtp.reportsuccess property is set, an SMTPAddressSucceededException will be included in the list for each address that is successful. Note that this will cause a top level SendFailedException to be thrown even though the send was successful.

The SMTP provider also supports ESMTP (RFC 1651). It can optionally use SMTP Authentication (RFC 2554) using the LOGIN, PLAIN, and DIGEST-MD5 mechanisms (RFC 2592 and RFC 2831).

To use SMTP authentication you’ll need to set the mail.smtp.auth property (see below) and provide the SMTP Transport with a username and password when connecting to the SMTP server. You can do this using one of the following approaches:

• Provide an Authenticator object when creating your mail Session and provide the username and password information during the Authenticator callback.Note that the mail.smtp.user property can be set to provide a default username for the callback, but the password will still need to be supplied explicitly.This approach allows you to use the static Transport send method to send messages.
• Call the Transport connect method explicitly with username and password arguments.This approach requires you to explicitly manage a Transport object and use the Transport sendMessage method to send the message. The transport.java demo program demonstrates how to manage a Transport object. The following is roughly equivalent to the static Transport send method, but supplies the needed username and password:

Transport tr = session.getTransport(“smtp”);

tr.connect(smtphost, username, password);

msg.saveChanges(); // don’t forget this

tr.sendMessage(msg, msg.getAllRecipients());

tr.close();

When using DIGEST-MD5 authentication, you’ll also need to supply an appropriate realm; your mail server administrator can supply this information. You can set this using the mail.smtp.sasl.realm property, or the setSASLRealm method on SMTPTransport.

SMTP can also optionally request Delivery Status Notifications (RFC 1891). The delivery status will typically be reported using a “multipart/report” (RFC 1892) message type with a “message/delivery-status” (RFC 1894) part. JavaMail does not currently provide direct support for these new MIME types, but you can process them as any other “multipart” or “message” content, using MimeMultipart and MimeMessage objects.

See below for the properties to enable these features.

Note also that THERE IS NOT SUFFICIENT DOCUMENTATION HERE TO USE THESE FEATURES!!! You will need to read the appropriate RFCs mentioned above to understand what these features do and how to use them. Don’t just start setting properties and then complain to us when it doesn’t work like you expect it to work. READ THE RFCs FIRST!!!

The SMTP protocol provider supports the following properties, which may be set in the JavaMail Session object. The properties are always set as strings; the Type column describes how the string is interpreted. For example, use

        props.put("mail.smtp.port", "888");

to set the mail.smtp.port property, which is of type int.

Name	Type	Description
mail.smtp.user	String	Default user name for SMTP.
mail.smtp.host	String	The SMTP server to connect to.
mail.smtp.port	int	The SMTP server port to connect to, if the connect() method doesn’t explicitly specify one. Defaults to 25.
mail.smtp.connectiontimeout	int	Socket connection timeout value in milliseconds. Default is infinite timeout.
mail.smtp.timeout	int	Socket I/O timeout value in milliseconds. Default is infinite timeout.
mail.smtp.from	String	Email address to use for SMTP MAIL command. This sets the envelope return address. Defaults to msg.getFrom() or InternetAddress.getLocalAddress(). NOTE: mail.smtp.user was previously used for this.
mail.smtp.localhost	String	Local host name used in the SMTP HELO or EHLO command. Defaults to InetAddress.getLocalHost().getHostName(). Should not normally need to be set if your JDK and your name service are configured properly.
mail.smtp.localaddress	String	Local address (host name) to bind to when creating the SMTP socket. Defaults to the address picked by the Socket class. Should not normally need to be set, but useful with multi-homed hosts where it’s important to pick a particular local address to bind to.
mail.smtp.localport	int	Local port number to bind to when creating the SMTP socket. Defaults to the port number picked by the Socket class.
mail.smtp.ehlo	boolean	If false, do not attempt to sign on with the EHLO command. Defaults to true. Normally failure of the EHLO command will fallback to the HELO command; this property exists only for servers that don’t fail EHLO properly or don’t implement EHLO properly.
mail.smtp.auth	boolean	If true, attempt to authenticate the user using the AUTH command. Defaults to false.
mail.smtp.submitter	String	The submitter to use in the AUTH tag in the MAIL FROM command. Typically used by a mail relay to pass along information about the original submitter of the message. See also the setSubmitter method of SMTPMessage. Mail clients typically do not use this.
mail.smtp.dsn.notify	String	The NOTIFY option to the RCPT command. Either NEVER, or some combination of SUCCESS, FAILURE, and DELAY (separated by commas).
mail.smtp.dsn.ret	String	The RET option to the MAIL command. Either FULL or HDRS.
mail.smtp.allow8bitmime	boolean	If set to true, and the server supports the 8BITMIME extension, text parts of messages that use the “quoted-printable” or “base64” encodings are converted to use “8bit” encoding if they follow the RFC2045 rules for 8bit text.
mail.smtp.sendpartial	boolean	If set to true, and a message has some valid and some invalid addresses, send the message anyway, reporting the partial failure with a SendFailedException. If set to false (the default), the message is not sent to any of the recipients if there is an invalid recipient address.
mail.smtp.sasl.realm	String	The realm to use with DIGEST-MD5 authentication.
mail.smtp.quitwait	boolean	If set to false, the QUIT command is sent and the connection is immediately closed. If set to true (the default), causes the transport to wait for the response to the QUIT command.
mail.smtp.reportsuccess	boolean	If set to true, causes the transport to include an SMTPAddressSucceededException for each address that is successful. Note also that this will cause a SendFailedException to be thrown from the sendMessage method of SMTPTransport even if all addresses were correct and the message was sent successfully.
mail.smtp.socketFactory.class	String	If set, specifies the name of a class that implements the javax.net.SocketFactory interface. This class will be used to create SMTP sockets.
mail.smtp.socketFactory.fallback	boolean	If set to true, failure to create a socket using the specified socket factory class will cause the socket to be created using the java.net.Socket class. Defaults to true.
mail.smtp.socketFactory.port	int	Specifies the port to connect to when using the specified socket factory. If not set, the default port will be used.
mail.smtp.mailextension	String	Extension string to append to the MAIL command. The extension string can be used to specify standard SMTP service extensions as well as vendor-specific extensions. Typically the application should use the SMTPTransport method supportsExtension to verify that the server supports the desired service extension. See RFC 1869 and other RFCs that define specific extensions.
mail.smtp.starttls.enable	boolean	If true, enables the use of the STARTTLS command (if supported by the server) to switch the connection to a TLS-protected connection before issuing any login commands. Note that an appropriate trust store must configured so that the client will trust the server’s certificate. Defaults to false.
mail.smtp.userset	boolean	If set to true, use the RSET command instead of the NOOP command in the isConnected method. In some cases sendmail will respond slowly after many NOOP commands; use of RSET avoids this sendmail issue. Defaults to false.
mail.smtp.ssl.protocols	string	Specifies the SSL protocols that will be enabled for SSL connections. The property value is a whitespace separated list of tokens acceptable to the javax.net.ssl.SSLSocket.setEnabledProtocols method.
mail.smtp.ssl.ciphersuites	string	Specifies the SSL cipher suites that will be enabled for SSL connections. The property value is a whitespace separated list of tokens acceptable to the javax.net.ssl.SSLSocket.setEnabledCipherSuites method.

In general, applications should not need to use the classes in this package directly. Instead, they should use the APIs defined by javax.mail package (and subpackages). Applications should never construct instances of SMTPTransport directly. Instead, they should use the Session method getTransport to acquire an appropriate Transport object.

嗅嗅今天发了个问题，apache REDIRECT_URL not set

  <LocationMatch “/web/.*\.html”>
        Options FollowSymLinks Includes
        AllowOverride None
        ErrorDocument 404 /detail.jsp
  </LocationMatch>

 在jsp里面拿不到  REDIRECT_URL 头

 一开始我还不知道有这个东西，上去apache查文档。。。

Purpose

Additional functionality. Allows webmasters to configure the response of Apache to some error or problem.Customizable responses can be defined to be activated in the event of a server detected error or problem.

e.g. if a script crashes and produces a “500 Server Error” response, then this response can be replaced with either some friendlier text or by a redirection to another URL (local or external).

Old behavior

NCSA httpd 1.3 would return some boring old error/problem message which would often be meaningless to the user, and would provide no means of logging the symptoms which caused it.

New behavior

The server can be asked to;

1. Display some other text, instead of the NCSA hard coded messages, or
2. redirect to a local URL, or
3. redirect to an external URL.

Redirecting to another URL can be useful, but only if some information can be passed which can then be used to explain and/or log the error/problem more clearly.

To achieve this, Apache will define new CGI-like environment variables, e.g.

REDIRECT_HTTP_ACCEPT=*/*, image/gif, image/x-xbitmap, image/jpeg
REDIRECT_HTTP_USER_AGENT=Mozilla/1.1b2 (X11; I; HP-UX A.09.05 9000/712)
REDIRECT_PATH=.:/bin:/usr/local/bin:/etc
REDIRECT_QUERY_STRING=
REDIRECT_REMOTE_ADDR=121.345.78.123
REDIRECT_REMOTE_HOST=ooh.ahhh.com
REDIRECT_SERVER_NAME=crash.bang.edu
REDIRECT_SERVER_PORT=80
REDIRECT_SERVER_SOFTWARE=Apache/0.8.15
REDIRECT_URL=/cgi-bin/buggy.pl


note the REDIRECT_ prefix.

At least REDIRECT_URL and REDIRECT_QUERY_STRING will be passed to the new URL (assuming it’s a cgi-script or a cgi-include). The other variables will exist only if they existed prior to the error/problem. None of these will be set if your ErrorDocument is an external redirect (i.e., anything starting with a scheme name like http:, even if it refers to the same host as the server).

 原来还有这样的东东，对apache的稳定性有信心，那应该就是resin的问题了，mod_caucho经常有各种奇怪的行为，上去resin网站一查。。发现：

3.0.18 – Feb 23, 2006

ConnectionPool needs to be a lifo to avoid accumulating too many pool items (rep b Kaminsky Leonid)

max-create-connections wasn’t included in DBPool (rep by Kaminsky Leonid)

(2006-02-15) mod_caucho was not properly handling check-interval larger than 32-bits (#926, rep by Mutsubu Inayama)

Changes in ./configure and Makefile for MacOSX EGREP libtool issue (#432, rep by jdane)

(2006-02-09) class-loader can now appear anywhere, not just first element (#924, rep by dlcr)

Amber inheritance needs to work with CMR (#301, rep by Francois Bertrand)

JMX Notifications on restart (#195, #237, rep by Erik Hartenian, Glenn Rush)

fmt:param wasn’t printing children for validation (#893, rep by Ed Hollingsworth)

Apache2 mod_caucho needs to grab REDIRECT_URL and REDIRECT_QUERY_STRING (#87, rep by A Jacklin)

change escaping of command line argument for WIN32 service installation (#141, rep by Steve Arbour)

哈哈，就这样解决了，升级吧。。。。