綾波的微笑
Fighting spam always costs
One of the important things about fighting spam, one that may not beimmediately obvious, is that there is no free lunch. Fighting spam cancost in the risk of false positives, or it can cost in people's time(sometimes you can spend money instead), but it always costs; youjust decide where you will pay the price.
(There are many ways that it can cost in people's time; for example,putting together and managing a spam filtering system. As illustratedhere,
聞一多"死水"
這是一溝絕望的死水，
清風吹不起半點漪淪。
不如多扔些破銅爛鐵，
爽性潑你的賸菜殘羹。
也許銅的要綠成翡翠，
鐵罐上銹出幾瓣桃花，
再讓油膩織一層羅綺，
黴菌給他蒸出些雲霞。
讓死水酵成一溝綠酒，
飄滿了珍珠似的白沫；
Improving your life with checklists
I recently migrated a fairly important chunk of our mail service from anold mailer on an old server to a new mailer on a new server. It wasn'ta simple process, as it involved moving data from the old server to ourSAN, updating all sorts of configurations, changing scripts, and variousother things. But I managed to do it smoothly, with only one or twomoments of panic, and one of the big reasons for this is I made adetailed checklist .
Well before I started the
老婦人
星期日到珠海買書，回澳排隊過關時遇上一個打尖的老婦人，婦人極老，是那種老得腰也無法挺直的年紀，她拖着一輛載了兩大箱貨物的行李車，大抵是靠運送貨物往返珠澳兩地維生的人，這“行業”在拱北關興盛了許多年，我
我們有什麼本錢？
Platform risk and platform (in)security
One of the perennial arguments between Mac people and Windows people iswhether or not Macs are better than Windows machines for staying safeon the Internet, and if they are, why this is so; not infrequently,the debates get quite heated. I think that one reason for this is thatpeople confuse the concepts of platform risk and platform (in)security,and thus miss something important:
Risk is not the same as insecurity.
(Here, a platform's risk is the likelihood that people using it will
十一月至今
２）天天不停吃但又不能做運動，我像一隻豬。
３）拆了gel nail，現在我的指甲可與SAW II poster媲美。
４）我在看«時裝時刻»。
５）拆了fake lashes，每朝洗面時我都不知道眼睛在哪。
６）朋友又一次搭上別人
What NAT is useful for
I can think of at least three things that NAT is good for:
- it compacts address space; many machines can be behind a single IPaddress.
- it makes a decent outgoing-traffic-only firewall, which provides asignificant amount of protection to machines.
- to some degree it denies outsiders what I'll call 'trafficintelligence'; how many machines you have, how they're grouped,and what machine or group is responsible for what traffic.
(Sometimes the lack of traffic intelligence can be a problem
Why vfork() got created (part 2)
Although fork() theoretically copies the address space of the parentprocess to create the child's address space, Unix normally does notactually make a real copy. Instead it marks everything as copy onwrite and then waits foreither the parent or the child to dirty a page, whereupon it does copiesonly as much as it has to. This makes forks much faster, which is veryimportant since things in Unix fork a lot.
(Disclaimer: this is the traditional implementation for paged virtualmemory. I don