Re: OT: 2D Barcodes on Junk Mail
- From: mpm <mpmillard@xxxxxxx>
- Date: Sat, 2 Aug 2008 09:19:58 -0700 (PDT)
On Aug 2, 3:10�am, Robert Baer <robertb...@xxxxxxxxxxxx> wrote:
� �Most of these stupidites are on forms where one is requesting
information.
� �One would think that a requester knows their own e-mail address and
if reasonably desirous of an answer, that they would enter their e-mail
correctly.
The problem is that validating an email in software is actually not
that trivial.
Obviously, you can check for ANY entry, that's easy.
If the field is left blank, the Server (or local script) can alert the
user. No big deal.
But once you get past that, it becomes a little tricky.
Some characters are invalid in email addresses, so you have to trap
for those.
An email must contain a single "@" sign, and at least 1 dot (and
possibily more), but not two adjacent dots. It must also end in a
valid suffix, like "com", "net", "us, "biz", etc.... And more are
being added all the time, so you would have to keep adjusting your
server or script code to handle that possibility. Finally, the email
address can contain no whitespaces, such as tabs, spaces, etc...
Then you have some characters which, while not prohibited in the
address, can confuse the hell out of software (both server & client
side, plus everything along the route.) These are characters like:
0x26H - "&" - which is a UNIX shell special character and must be URL
encoded anyway.
0x27H - The apostrophe, (which might get lost in subsequently quoted
text).
0x2AH - The "*" asterisk, which is often used as a wildcard
0x2CH - The comma, which is used to separate email addresses from each
other
0x2FH - The forward slash
...you get the idea, and if not, here's a listing and completel
explaination of some of the potentially confusing aspects of these and
other characters when used in an email address:
http://www.remote.org/jochen/mail/info/chars.html
So, given all of this, it's often easier (in software - either server
side or local script) to just ask the respondant to enter their email
address information twice and do a simple string comparison. If
either field is missing, or if the two fields don't match - that's
usually good enough to flag as an error.
Mike is absolutely right. We collect info from our customers all the
time. We often get bad info on forms. You would be amazed how many
people use a URL for a valid email address, for example. (Some folks
evidently don't know the difference!)
-mpm
.
- References:
- Re: OT: 2D Barcodes on Junk Mail
- From: Robert Baer
- Re: OT: 2D Barcodes on Junk Mail
- From: Michael A. Terrell
- Re: OT: 2D Barcodes on Junk Mail
- From: Robert Baer
- Re: OT: 2D Barcodes on Junk Mail
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