eval的作用: 主要用來做變數的二次迭代

http://linux.vbird.org/linux_basic/0320bash/0320bash.php

vim的視窗分割快捷鍵

在command mode中輸入:

1) sp  水平分割
2) vs  垂直分割

BYOD的簡介

BYOD=Bring Your Own Device

http://www.managertoday.com.tw/?p=12359

列出CitrixXenserver 所有的VLAN tag (以遞增的方式排序)

xe vlan-list params=tag --minimal | awk 'BEGIN{FS=","} {for(i=1;i<NF;i++) print $i}' | sort -n | uniq

bash array的寫法範例

http://go-linux.blogspot.tw/2007/03/basharray.html

http://www.cyberciti.biz/faq/finding-bash-shell-array-length-elements/

http://www.thegeekstuff.com/2010/06/bash-array-tutorial/

http://stackoverflow.com/questions/688849/associative-arrays-in-shell-scripts

awk的BEGIN與END區塊

BEGIN
 A BEGIN rule is executed, once, before the first input record has been read

PS:
If an awk program only has a BEGIN rule, and no other rules, then the program exits after the BEGIN rule has been run. (Older versions of awk used to keep reading and ignoring input until end of file was seen.)



END
An END rule is executed, once, after all the input has been read


BEGIN and END rules must have actions; there is no default action for these rules since there is no current record when they run.



Reference
[1] awk的BEGIN與END區塊, http://lalakiwe.myweb.hinet.net/Documents/awk/awk_appendix.html
[2] http://www.staff.science.uu.nl/~oostr102/docs/nawk/nawk_52.html

awk的loop使用方法

awk 的loop使用方法
http://www.cnblogs.com/chengmo/archive/2010/10/04/1842073.html

8 Powerful Awk Built-in Variables – FS, OFS, RS, ORS, NR, NF, FILENAME, FNR

http://www.thegeekstuff.com/2010/01/8-powerful-awk-built-in-variables-fs-ofs-rs-ors-nr-nf-filename-fnr/

Object Storage Device

An Object-based Storage Device (OSD) is a computer storage device, similar to disk storage but working at a higher level. Instead of providing a block-oriented interface that reads and writes fixed sized blocks of data, an OSD organizes data into flexible-sized data containers, called objects. Each object has both data (an uninterpreted sequence of bytes) and metadata (an extensible set of attributes describing the object).


Reference:
[1] http://en.wikipedia.org/wiki/Object_storage_device
[2] http://lab.howie.tw/2013/04/Object-based-storage-vs-bolck-device-storage.htm
[3] https://researchweb.watson.ibm.com/haifa/projects/storage/objectstore/papers/PositionOSD.pdf
[4] http://www.ascc.sinica.edu.tw/sysinfo/storage/conference/object-sun.pdf

keystone endpoint系列api

endpoint-create     Create a new endpoint associated with a service
endpoint-delete     Delete a service endpoint
endpoint-get           Find endpoint filtered by a specific attribute or service type
endpoint-list           List configured service endpoints

endpoint-create

keystone endpoint-create [--region <endpoint-region>]  \
                                             --service-id <service-id> \ 
                                             [--publicurl <public-url>] \
                                             [--adminurl <admin-url>] \
                                             [--internalurl <internal-url>]

endpoint-delete

endpoint-get

endpoint-list

sed進階應用

sed  's/被取代的字串/要取代的字串/'

sed -r 's/^(admin_token) = (.*)/\1 = '要代換的token'/g'

\1: 代表暫存，然後在要取代的字串中取回
-r , regular expression


# sed的examples
http://www.theunixschool.com/2012/06/sed-25-examples-to-delete-line-or.html
http://www.grymoire.com/Unix/Sed.html

eval - construct command by concatenating arguments

http://unix.stackexchange.com/questions/23111/what-is-the-eval-command-in-bash

SSH Tunneling(a.k.a SSH Port Forwarding)

Port forwarding, or tunneling, is a way to forward otherwise insecure TCP traffic through SSH Secure Shell. You can secure for example POP3, SMTP and HTTP connections that would otherwise be insecure.

Local Tunneling

Remote Tunneling

Linux Bridge

http://benjr.tw/node/387

monit

http://portable.easylife.tw/2407

用來監控System、Process的lightweight的監控軟體