Read output from a Python command in a PHP webapp

Question

I'm trying to read python output from a php webapp.

I'm using $out = shell_exec("./mytest") in the php code to launch the application, and sys.exit("returnvalue") in the python application to return the value.

The problem is that $out doesn't contain my return value. Instead if I try with $out = shell_exec("ls"), $out variable contain the output of ls command.

If I run ./mytest from terminal it works and I can see the output on my terminal.

Martin Tournoij · Accepted Answer · 2014-12-05 11:25:55Z

1

sys.exit("returnvalue")

Using a string with sys.exit is used to indicate an error value. So this will show returnvalue in stderr, not stdout. shell_exec() only captures stdout by default.

You probably want to use this in your Python code:

print("returnvalue")
sys.exit(0)

Alternatively, you could also use this in your PHP code to redirect stderr to stdout.

$out = shell_exec("./mytest 2>&1");

(In fact, doing both is probably best, since having stderr disappear can be quite confusing if something unexpected happens).

answered Dec 5, 2014 at 11:25

Martin Tournoij

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2 Comments

stafanovinci Over a year ago

print("returnvalue") sys.exit(0) doesn't works...$out = shell_exec("./mytest 2>&1") works but it returned only the last line, and, unfortunately, panda3d add 2 messages lines after my return value...

Martin Tournoij Over a year ago

@stafanovinci I don't know your Python code, or your PHP code for that matter. I can't point out any errors in code I don't know about ;-). This is the error in the code that you posted...

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