On 06/09/2010 11:40 PM, J wrote: > Does anyone know of a way, or have a recipe, to do a linux printk > equivalent in Python? > > I've been googling for a while and not finding anything useful. > > The nutshell version of this is that I need to write a routine for a > test tool I'm working on that will time the amount of time used to > take a system and go from Live to Suspended and then from Suspended to > Live.
as "News123" has said, it's probably not possible, simply because (AFAIK) printk is a kernel-internal function. Even if it were callable from user space, it would be a system call, so ctypes probably wouldn't help you, since that operates on shared libraries (correct me if I'm wrong, anyone) But how about - the syslog. I expect your syslog daemon copies kernel messages to the log, and you can write to that. > > I can get all the times I need from the kernel message buffer (via > dmesg) but one of the test cases involves doing 30 suspend/resume > cycles, so I'll end up having to parse and weed out a lot of redundant > data. > > One idea I had was to just flush the buffer (calling dmesg -c) but > that's not the nicest way of doing things on an end user's system. > > SO, the thought I had was to just inject a marker like "START SUSPEND > TEST hash" where hash is a unique identifier for that test run, either > the number of the run (1 - 30) or a timestamp or whatever... it just > has to be unique > and then inject a "FINISHED SUSPEND TEST has" marker after the system > is fully live. > > THEN I could just look for those two markers and parse the data in > between them for the timestamps I need. > > but I can't find any way so far, in python to write kernel messages. > Perhaps this is something for ctypes? (though I'm trying to keep from > introducing non-python code if at all possible) and I've never used > ctypes before and have no real idea how to use them (perhaps this > would be a good, easy way to learn?) > > I'm going to start looking at ctypes after sending this and maybe > learn something new today, but I also wanted to ask the list for > suggestions as well. > > Cheers, > > Jeff > > And yes, this is not something that would be portable to a non-Linux > OS, but that's ok, because this is strictly a Linux tool anyway. -- http://mail.python.org/mailman/listinfo/python-list
