Problem reading the result of a Process (Bridge Library, Arduino YUN)

[Roque Campos]

Dear Friends,

I'm using the Process class of the Bridge library to make a curl request and trying to read the result in a String Variable. My code is like the folowing;

Code: [Select]

Process p;
p.runShellCommand(curl_command);

while(p.running());  //Wait
  String result="";
  while (p.available()>0) {
   char c=p.read();
   result=result +c;
   Serial.print (c);
  }


The result of the curl command is a json string:

[{"id":"8","d":"2013-10-19 11:58:24","c":"roro","m":"on","com":"0","date_com":"0000-00-00 00:00:00"}]

The Rest service is working well (I tried the curl command from the linino command line).

The problem is that the while loop never ends. It reads, more or less

[{"id":"8","d":"2013-10-19 11:58:24","c":"roro","m":"on","com":"0","date_com... and then, a lot of strange ascii characters.

I taked the way of reading a Process result from the ShellCommand example. What I'm doing wrong?

Thanks in advance.

R.

[PaulS]

What I'm doing wrong?

Posting in the wrong place.

[Roque Campos]

Sorry about that, I thought that this was the correct subforum.

After a lot of tests, I managed to solve it myself. The problem is that the Json response is too long. If I modify the json and only return two fields, It works well.

Maybe a moderator can move this to te yun subforum. Maybe it's usefull for someone else.

Thanks.

[federicofissore]

I think you've hit a bug of the Bridge we've already fixed and that will be part of version 1.5.5 of the IDE. Try downloading a nightly version from http://arduino.cc/en/Main/Software#toc4, restore your json and retry

[Roque Campos]

Thank you for your answer. I followed your advice without success. But I think I have a clue. I called a wrong url by mistake, that returned the following result:

<h1>Not Found</h1>The requested URL /rest/do.php was not found on this server.


This response is a relatively long compared with my json. And with this response it works well. Then I suppose that the problem is inside the process class executing the curl command and waiting for the response.

I will try another approach to query my  mysql server and obtain the data while this problem persists.

Thank you again for your answer.