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Author Topic: Need to read a simple string stream from an IP address  (Read 1665 times)

AlanTheBeast

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Need to read a simple string stream from an IP address
« on: September 25, 2016, 07:47:53 pm »
Hi,

I don't use Lazarus, just FPC command line (via Lightweight).

I have a nifty app on my iPhone called SensorLog and it will output whatever sensor data from the phone one sets up to an IP address and a set port.  I can telnet that to the terminal such as
 
$ telnet 192.168.1.22 60444
or
$ telnet 192.168.1.22 60444 > a_file.csv

but I can't get a named pipe or directed pipe to read in the stream.

Is there some "light" unit that will allow me to read the stream?

Something like

     - set an IP address and port as a textfile or a stream
     - read from it until dizzy
     - close when done


Thanks

Phil

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Re: Need to read a simple string stream from an IP address
« Reply #1 on: September 25, 2016, 07:51:39 pm »
Not sure if I follow.

Does an HTTP request using FPC's TFPHTTPClient class work? (fphttpclient unit)


AlanTheBeast

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Re: Need to read a simple string stream from an IP address
« Reply #2 on: September 26, 2016, 12:51:42 am »
I don't know Phil - but now that you've pointed me at that unit I'll see what I see!


Phil

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Re: Need to read a simple string stream from an IP address
« Reply #3 on: September 26, 2016, 01:00:49 am »
I might have misunderstood what you're doing.

Are you using telnet on a computer as a way to read from the iOS app sends?

I think that for an HTTP request to work, the iOS app would need to act like a Web app running under a Web server. That is, when it receives a request for data, it returns it in a response. From the description on the app store, it appears as though it SensorLog can do that:

https://itunes.apple.com/us/app/sensorlog/id388014573?mt=8

I believe iOS includes a Web server (Apache) because I've seen an iOS app that works like a Web app. Perhaps SensorLog is using the server to service the HTTP requests.




Thaddy

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Re: Need to read a simple string stream from an IP address
« Reply #4 on: September 26, 2016, 06:30:00 am »
Http should work since it is explicitly supported by SensorLog. see docs in appstore that reads: per HTTP GET/POST.

In that case it should be very easy with TFPHttp and trivial with synapse.

[edit]
The httpget example in /packages/fcl-web/examples/httpclient/ works straight out of the box, tested against an apache server.
usage: httpget <url> <filename>

With synapse use:
Code: Pascal  [Select]
  1. function HttpGetText(const URL: string; const Response: TStrings): Boolean;// in httpsend.pas

There's TCP/IP only streaming client example in this blogpost by forum member leledumbo:
http://pascalgeek.blogspot.nl/2012/06/encryption-decryption-and-asynchronous.html
Scroll-down a bit.
« Last Edit: September 26, 2016, 06:54:57 am by Thaddy »
"Logically, no number of positive outcomes at the level of experimental testing can confirm a scientific theory, but a single counterexample is logically decisive."

 

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