When calling a Python script from a PHP script, temporary file that is created on a console run, is not created via the PHP invocation

Question

Scenario:

I have a php page in which I call a python script.

Python script when run on the command line (Linux) shows output on the command line, as well as writes the output to a file.

Python script when run through php, doesn't do either.

Elaboration:

I use a simple system command in PHP to run the python script as:

/var/www/html/1.php: system('/usr/python/bin/python3 ../cgi-bin/tabular.py 1');

/var/www/cgi-bin/tabular.py --This python file basically parses a data file, uses python's regular expression to search for specific headings and outputs the headings to the stdout, as well as write it to a file.

This python script has a few routines in it which get executed, so I put print statements to debug. I noticed only a few initial print statements' output in the PHP page, all the ones from the function that actually does something are not seen.

Also, as part of my test, I thought well the py script is in a different folder so let me change it to the /var/www/html folder, no go.

I hope I captured the problem statement with sufficient detail and someone is able to reproduce this issue at their end. If I make any progress on this one myself, I'll annotate this question. Thanks everyone.

Gaurav

hegemon · Accepted Answer · 2009-05-29 13:09:39Z

2

I bet your py script has some bug which couses it to break when called from inside PHP. Try

passthru('/usr/python/bin/python3 ../cgi-bin/tabular.py 1 2>&1');

to investigate (notice 2>&1 which causess stderr to be written to stdout).

answered May 29, 2009 at 13:09

hegemon

6,8242 gold badges34 silver badges31 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

gsvolt Over a year ago

Thankyou hegemon. Using your advice, when I redirected the output I found the root cause - relative path for the data file in my globalvariables.py script was not being resolved correctly - I gave the complete path and this solved the problem.

gahooa · Accepted Answer · 2009-05-29 05:14:54Z

1

A permission problem is most likely the case.

If apache is running as apache, then it will not have access to write to a file unless

The file is owned by apache
The file is in the group apache and group writable
The file is world writable

This is a "sticky" problem on a multi-user machine, as different people have access to Apache.

Try chmod 666 output.txt on the file and then re-run your test.

Considerations:

Have the python script write the output to a database
Use PHP's popen functionality to open the process and communicate over pipes
Re-write using PHP's regular expressions
Write the output file to /tmp and then read the results using PHP as soon as the python script is done.
etc...

answered May 29, 2009 at 5:14

gahooa

138k14 gold badges101 silver badges104 bronze badges

Comments

TML · Accepted Answer · 2009-05-28 23:48:39Z

0

Check that the user the python script is running is has write permissions in CWD. Also, try shell_exec() or passthru() to call the script, rather than system().

answered May 28, 2009 at 23:48

TML

13k3 gold badges42 silver badges47 bronze badges

2 Comments

gsvolt Over a year ago

Hi TML, with passthru, same outcome is observed. Also, chmod 755 has been performed across all .py files in /var/www/cgi-bin Thanks for the response, I'm going to keep at this problem as the output of print in the .py should be visible in the .php page.

John Carter Over a year ago

The issue will be with the write permission of the output directory, write permission on the script is irrelevant.

Collectives™ on Stack Overflow

When calling a Python script from a PHP script, temporary file that is created on a console run, is not created via the PHP invocation

3 Answers 3

1 Comment

Comments

2 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

1 Comment

Comments

2 Comments

Your Answer

Sign up or log in

Post as a guest

Related