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I'm trying to build a web interface for some python scripts. The thing is I have to use PHP (and not CGI) and some of the scripts I execute take quite some time to finish: 5-10 minutes. Is it possible for PHP to communicate with the scripts and display some sort of progress status? This should allow the user to use the webpage as the task runs and display some status in the meantime or just a message when it's done.

Currently using exec() and on completion I process the output. The server is running on a Windows machine, so pcntl_fork will not work.

LATER EDIT: Using another php script to feed the main page information using ajax doesn't seem to work because the server kills it (it reaches max execution time, and I don't really want to increase this unless necessary)

I was thinking about socket based communication but I don't see how is this useful in my case (some hints, maybe?

Thank you

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You want inter-process communication. Sockets are the first thing that comes to mind; you'd need to set up a socket to listen for a connection (on the same machine) in PHP and set up a socket to connect to the listening socket in Python and send it its status.

Have a look at this socket programming overview from the Python documentation and the Python socket module's documentation (especially the examples at the end). I'm sure PHP has similar resources.

Once you've got an more specific idea of what you want to build and need help, feel free to ask a new question on StackOverflow (if it isn't already answered).

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I combined this with ajax/javascript polling to avoid reaching max execution time and it works just fine! Thanks
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I think you would have to use a meta refresh and maybe have the python write the status to a file and then have the php read from it.

You could use AJAX as well to make it more dynamic.

Also, probably shouldn't use exec()...that opens up a world of vulnerabilities.

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The user has no control over the scripts executed so I don't see how exec would be a problem (the alternative would be proc_open).
Please check my "later edit" in the main post for ajax.I was thinking about socket based communication but I don't see how is this useful in my case (some hints, maybe?)
@stefan Security is about being as paranoid as possible. Look what happened to Sony with PSN; they assumed the user would never be able to tamper with their PS3.
@Beau Martinez True, but this page has only internal visibility (not accessible outside our network). Even so, you have a valid point
Looking at this, I like the concept of writing to a file-- it seems easier than relying upon sockets.
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You could use a queuing service like Gearman, with a client in PHP and a worker in Python or vice versa.

Someone has created an example setup here.

https://github.com/dbaltas/gearman-python-worker

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Unfortunately my friend, I do believe you'll need to use Sockets as you requested. :( I have little experience working with them, but This Python Tutorial on Sockets/Network Programming may help you get the Python socket interaction you need. (Beau Martinez's links seem promising as well.)

You'd also need to get some PHP socket connections, too, so it can request the status.

Continuing on that, my thoughts would be that your Python script is likely going to run in a loop. Ergo, I'd put the "Check for a status request" check inside the beginning of a part of that loop. It'd reply one status, while a later loop inside that script would reply with an increased status.. etc.

Good luck!

Edit: I think that the file writing recommendation from Thomas Schultz is probably the easiest to implement. The only downside is waiting for the file to be opened-- You'll need to make sure your PHP and Python scripts don't hang or return failure without trying again.

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Regarding files, you'd have to check the files for changes yourself (if you're on a platform that supports it you can poll for changes). This is taken care for you with (default, non-blocking) sockets: the code waits until there are changes.

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