[TCP/IP] IP/TCP/UDP Headers

TOS - RFC1349
DSCP - RFC2474
ECN - RFC3168

[gdb] gcore - Produce a Core from Within GDB

A "core file" or "core dump" is a file that records the memory image of a running process and its process status (register values etc.). Its primary use is post-mortem debugging of a program that crashed while it ran outside a debugger. A program that crashes automatically produces a core file, unless this feature is disabled by the user.

Occasionally, you may wish to produce a core file of the program you are debugging in order to preserve a snapshot of its state. GDB has a special command for that.

`generate-core-file [FILE]'
`gcore [FILE]'

Produce a core dump of the inferior process. The optional argument FILE specifies the file name where to put the core dump. If not specified, the file name defaults to `core.PID', where PID is the inferior process ID.

Note that this command is implemented only for some systems (as of this writing, GNU/Linux, FreeBSD, Solaris, Unixware, and S390).

[Bash] bashdb - Bash Debugger

bashdb 的用法跟 gdb 和 perldb 类似, 不过更接近 perldb. bashdb 还能像 gdb 那样在 emacs 里面使用, 很方便.

[Google] Blogger.com 真是不错

除了在 Blogger 上直接写文章之外, 还可以采用以下两种方式:

• 发 mail 到一个 address, mail 内容就能自动 post 到 blog 上去, 唯一不方便的就是不能指定 label
  
• 在 Google Docs & Spreadsheets 里面可以直接将文章 post 到 blog 上去

总的来讲还是不错啦 :)

谁动了我的系统

上周六下班回家前正常 shutdown 了我的 win2k 和 Ubuntu, 周一上班来开机的时候出现了两个问题: win2k 启动时进行了磁盘检测, 如果正常关机的话不会这样的; Ubuntu 正常启动失败, 只能进入 single 模式. 经过一番 probe, 发现在 /etc/rc3.d/ 下面多了两个 link: udev 和 single. udev 应该只在 /etc/rcS.d/ 下面才有的, 如果 rc3.d/ 里面再 link 一个, 将会导致 udev 执行两次而 fail; single 也只应出现在 rc1.d/ 下面的. 综合以上情况分析, 最大的可能就是有人私下进入我的系统了, 不过又好像不可能, 我的系统里面又没有什么值钱的东东. 郁闷...

[Ubuntu] invoke-rc.d

invoke-rc.d is a generic interface to execute System V style init script /etc/init.d/name actions, obeying runlevel constraints as well as any local policies set by the system administrator.
All access to the init scripts by Debian packages' maintainer scripts should be done through invoke-rc.d.
This manpage documents only the usage and behavior of invoke-rc.d. For a discussion of the System V style init script arrangements please see init(8) and the dpkg Programmers' Manual. More information on invoke-rc.d can be found in the section on runlevels and init.d scripts of the Debian Policy Manual.
-- Man page of invoke-rc.d(8)

New Blogger.com

为了更好的利用 Blogger.com 的新 features, Google 建议把老的 blog 搬家到新的 blog 上来, 以后就只能用 Google 帐号登录了. 还好, 原有的所有 settings 都没有丢失. Cool is Google!