Communication between a Python process and a Python cgi script

[Joonas Paalasmaa]

Donn Cave wrote:
> Quoth Joonas Paalasmaa <joonas at olen.to>:
> | I have a Python program started by root that does some magic stuff
> | every 10 minutes. So the program in an infinite loop of sleep, do stuff,
> | sleep, do stuff... How can I make a cgi-script to end the process's
> | sleep phase and make it to "do stuff" immediately. I tried signals, but
> | it is propably too risky because the process is run as root. Any
> | suggestions?
> 
> You could try a named pipe -
> $ mkfifo /tmp/fifo
> $ cat /tmp/ptest
> pipe = open('/tmp/fifo', 'r')
> while 1:
>     ping = pipe.read()
>     print 'ping', repr(ping)
> $ python /tmp/ptest &
> $ echo junk > /tmp/fifo
> ping 'junk\n'
> $ echo junk > /tmp/fifo
> ping 'junk\n'
> 
> Find a better name and place for the fifo, check that it will be
> writable by the CGI process.  Consider security issues, who will
> be able to do this - might be no compromise, yet you could have
> a "denial of service" kind of attack.

Thanks! This is exactly what I needed.

- Joonas