web page change monitoring

[Nick Goldman]

I'm thinking about a simple monitor to check every so often whether a
specified web page has changed.

I thought of doing this by triggering an event every few minutes,
getting the web page, checking if it had changed since last time, and
alerting me if it had.

I could use HTTP GET to get the file. What's troubling me at the
moment is how to check if it is different to the last time. Is there
a checksum facility in tasker that would help me do this? I'd rather
just compare the new checksum with the last one --- and anyhow I don't
know how to do a file comparision any other way in tasker.

Thanks for any tips,

Nick

[Pent]

This is really waiting for the HTTP Head action (just returns status
information, not the page itself).

Currently I guess you could use HTTP Get and use Misc / Test to
calculate a checksum

Pent

[Pak]

This might be a task that is easier done with something like http://www.changedetection.com/ where you can register, tell it which pages you want monitored, then get emails when changes are detected. So rather than make tasker try and detect web page changes, instead just have it monitor for emails sent from http://www.changedetection.com/

[Pent]

It's not so hard with Tasker even without HTTP Head:

Time: Repeating, 1 Hour
Task:
HTTP Get
Variable Convert, %HTTPD, %httpsum
If %httpsum != %LastSum
Variable Set, %LastSum, %httpsum
Alert / Flash, Document Changed!

Pent

[Nick Goldman]

Thanks all. I am implementing pent's suggestion, but a couple of
things about the Variable Convert instruction:

On Oct 5, 8:33 am, Pent <supp...@apps.dinglisch.net> wrote:
> HTTP Get
> Variable Convert, %HTTPD, %httpsum

First, Variable Convert doesn't like it if I ask it to convert %HTTPD
- "Error: built-in variables cannot be modified." I could copy %HTTPD
to another variable first, but am I missing something more elegant?

Second, what do I best convert it *to*? "MD5 Digest"? "SHA1
Digest"? Is one better than another?

Thanks again,

Nick

[Pent]

> First, Variable Convert doesn't like it if I ask it to convert %HTTPD
> - "Error: built-in variables cannot be modified."  I could copy %HTTPD
> to another variable first, but am I missing something more elegant?

Ah, it shouldn't do that if you're converting to another variable,
will fix that.
Just copy it for now.

> Second, what do I best convert it *to*?  "MD5 Digest"?  "SHA1
> Digest"?  Is one better than another?

Almost certainly, but analysis of hashing algorithms is beyond the
scope of
my user-support for Tasker :-)

You just want the fastest for this purpose.

Pent