PHP exec() not working as expected

[boylesg]

I have installed apache on my RPi.

And I have a very simple php web page.

All I am doing is calling exec("python StartCamera.py", $arrayOutput, $nReturn); and then echoing the results.

All I get is 255.

I should be getting an error message because the camera is not connected.

If I run this code in Python3 then I get a very verbose error message.

What is that I have to do to see the same error message on my web page?

[SonOfAMotherlessGoat]

Looks like you are getting the return code from your exec() call.

Can you post the code from the entire page? (Use the

Code: Select all

[/b] blocks if you please.)

[boylesg]

Looks like you are getting the return code from your exec() call.

Can you post the code from the entire page?

I just noticed a typo in my code "print_r($rrayOutput);" instead of "print_r($arrayOutput);"
But I fixed it as below and now I get "Array ( [0] => * failed to open vchiq instance ) 255" on my web page.

Code: Select all

<?php
     $strCmd = "python StartCamera.py";
     $arrayOutput = array();
     $nReturn - 0;
     exec($strCmd, $arrayOutput, $nReturn);
     echo "<br><br>";
     print_r($arrayOutput);
     echo "<br>"  + $nReturn + "<br><br>";
?>

[stderr]

now I get "Array ( [0] => * failed to open vchiq instance ) 255" on my web page.

Isn't that due to whatever user is running the code isn't part of the video group?

[boylesg]

now I get "Array ( [0] => * failed to open vchiq instance ) 255" on my web page.

Isn't that due to whatever user is running the code isn't part of the video group?

You tell me - I am new to doing web pages on Raspberry Pi.

How do I fix it?

[SonOfAMotherlessGoat]

Possibly you need to add the user that the webserver is executing your python as into the video group.

[stderr]

now I get "Array ( [0] => * failed to open vchiq instance ) 255" on my web page.

Isn't that due to whatever user is running the code isn't part of the video group?

You tell me - I am new to doing web pages on Raspberry Pi.
How do I fix it?

I could guess that it is probably the same as whatever the thing is that you are calling it from. But can you run your python code and save things to a file you can look at? Because you could run a python command that said whatever is the python equivalent of whoami and then you'd probably know.

[tony power]

I think this will solve your issue

Code: Select all

sudo chmod 777 /dev/vchiq
sudo chown www-data:www-data -R /var/www

[SonOfAMotherlessGoat]

Code: Select all

sudo chmod 777 /dev/vchiq
sudo chown www-data:www-data -R /var/www

First line, BAD. (And under most installation will be reset by udev when you reboot anyways, cause, well, it's BAD.)
Second line, under Jessie the directory is /var/www/html for the www-data group.