= 2011-04-15 =

== netstat ==

 * 加一個 -o 參數可以看到 timewait 還剩下多久。
 * 謎：明明已經把 net.ipv4.tcp_fin_timeout、net.ipv4.netfilter.ip_conntrack_tcp_timeout_fin_wait、net.ipv4.netfilter.ip_conntrack_tcp_timeout_time_wait 都調到 10 秒了，為啥還是有 60 附近的秒數哩？！
{{{
~$ netstat -tnao | cut -b 42- |grep TIME_WAIT | sort
   123.117.180.2:47670     TIME_WAIT   timewait (24.27/0/0)
   123.117.180.2:47687     TIME_WAIT   timewait (7.83/0/0)
   123.117.180.2:47688     TIME_WAIT   timewait (7.99/0/0)
   123.117.180.2:47689     TIME_WAIT   timewait (12.66/0/0)
   123.117.180.2:47690     TIME_WAIT   timewait (20.88/0/0)
   123.117.180.2:47736     TIME_WAIT   timewait (13.10/0/0)
   123.117.180.2:47759     TIME_WAIT   timewait (33.21/0/0)
   123.117.180.2:47761     TIME_WAIT   timewait (28.48/0/0)
   123.117.180.2:47793     TIME_WAIT   timewait (33.87/0/0)
   123.117.180.2:47804     TIME_WAIT   timewait (47.01/0/0)
   123.117.180.2:47858     TIME_WAIT   timewait (44.61/0/0)
   123.117.180.2:47865     TIME_WAIT   timewait (42.52/0/0)
   123.117.180.2:47971     TIME_WAIT   timewait (51.43/0/0)
   123.117.180.2:47979     TIME_WAIT   timewait (52.00/0/0)
   123.117.180.2:47990     TIME_WAIT   timewait (53.79/0/0)
   123.117.180.2:47992     TIME_WAIT   timewait (53.89/0/0)
   163.21.245.128:50304    TIME_WAIT   timewait (11.30/0/0)
   163.21.245.128:50305    TIME_WAIT   timewait (13.62/0/0)
}}}
== Multicast Socket Programming ==

 * Perl:
   * CPAN - [http://search.cpan.org/~bramble/IO-Socket-Multicast-1.12/ IO::Socket::Multicast] - Send and receive multicast messages
    * [http://packages.debian.org/libio-socket-multicast-perl 有 Debian 套件 libio-socket-multicast-perl]
   * [http://gradew.net/?p=87&lang=en Multicast with C and Perl on Linux]
    * [http://gradew.net/downloads/multicast.zip 原始碼下載: multicast.zip]
 * Python:
   * 使用 twisted - [http://code.activestate.com/recipes/425975-simple-udp-multicast-client-server-using-twisted/ 範例: Simple UDP Multicast Client / Server using twisted]
   * [http://coobs.eu.org/py-multicast/ py-multicast] - A lightweight Python IP multicast library
    *  [http://stackoverflow.com/questions/603852/multicast-in-python 範例: Multicast in Python]

== infographics ==

 * [http://www.inside.com.tw/2011/04/13/infographics 做圖表也是一門學問：淺談超吸睛的資訊圖表（infographics)]
 * [[Image(http://static.inside.com.tw/wp-content/uploads/2011/04/Guide-to-Social-Media-for-Business.jpg,width=800)]]
 * [http://www.inside.com.tw/2011/04/29/infographic-how-to 製作視覺資訊圖表（infographic）的三大要素及相關工具]