Interesting and enlightening video. I often think I know why I do what I do, being able to give a convincing and logical explanation on a certain action which I happened to perform. Under the same conditions at another time and place I may very possibly choose to perform some other actions, and I can very well be able to give an equally convincing explanation.
Falsehoods programmers believe about email
I will be the first to admit that I make all kinds of assumptions when seeing an email address from someone.
- Everyone has an email address
- Everyone has exactly one email address
- An email address never changes
- Whenever an address does change, it’s under that user’s control
- Whenever an address does change, it’s because the user specifically requested it to happen
- Whenever an address does change, the old address will continue to work/exist
- Any one email address refers to only one single person
- Unique strings of characters all map to different addresses
- All email is hosted by a centralized system
- When email is sent to a user at a domain, it is delivered to a server whose address matches that domain
- When email is sent by a user at a domain, it is sent by a server whose address matches that domain
- All email comes from a
- You can filter out email based on the TLD or ccTLD from which it originates
- Having a particular ccTLD means that you prefer to receive communications in that country’s native language (for example,
- Email addresses only contain letters
- Email addresses only contain letters and numbers
- Email addresses only contain letters, numbers, and a handful of common punctuation marks (e.g.
- Email addresses will have at least one letter in them
- An email address like
- Email is a reliable transport
- Email is an instantaneous transport
- Emails will be sent within a few minutes of their scheduling
- Emails will be sent within a few hours of their scheduling
- Emails will be sent within a few days of their scheduling
- Emails will be received soon after they’re sent
- When an email is sent it immediately goes to its destination server
- If an email bounces, the address is invalid
- If an email doesn’t bounce, the address is valid
- An address which is valid will always be valid, and an address which is invalid will always be invalid
- All email is sent via SMTP over TCP/IP port 25
- All email is sent via SMTP over TCP/IP
- All email is sent via SMTP over IP
- All email is sent via SMTP
- All email servers support the various vendor extensions by the current “everyone uses this vendor” vendor (Microsoft, Google, etc.)
- An email can only have one
Date:header on a message is legitimate
Received:headers will always be no earlier than the
- All email clients support HTML attachments
- All email clients support HTML message bodies
- All email clients support MIME encoding
- Email is secure
- Encrypted email is secure
- All email is accessed via webmail
- All email is accessed via webmail or IMAP
- All email is accessed via webmail, IMAP, or POP3
- Nobody uses email anymore
True size of countries
It is hard to represent our spherical world on flat piece of paper. Even though Greenland looks really big on the map, Greenland being 0.8 million sq. miles is much smaller than Africa being 11.6 million sq. miles.
Psychology and life
IAM is basically
Who can do what to which resources. When do we care?
>>> flag = "🇺🇸"
>>> reversed_flag = flag[::-1]
A library that does the reverse operation correctly.
docker compose file creation
This tool will convert a docker run command into a docker compose file.
ENTRYPOINT vs CMD
ENTRYPOINT specifies a command that will always be executed when the container starts.
CMD specifies arguments that will be fed to the
FROM debian:wheezy ENTRYPOINT ["/bin/ping"] CMD ["localhost"]
$ docker run -it img google.com
Turns out incognito mode doesn’t quite protect privacy, websites can still track us.