On Dec 11, 3:10 pm, james.o...@gmail.com (James Olin Oden) wrote: > On Fri, Dec 11, 2009 at 4:36 PM, Shawn H Corey <shawnhco...@gmail.com> wrote: > > > James Olin Oden wrote: > >> Hi All, > > >> This is really not a beginner question but I'm not sure what list to post > >> it on. > > >> I've created a daemon library for easily building daemons and at some > >> point code was added to handle closing all fd's so the daemonized > >> process would not have fd's hanging around it shouldn't have or didn't > >> expect to have. The code to close the fd was using POSIX::close(), > >> and this was a bad idea because, though it closes the fd, it leaves > >> any perl filehandles associated with the fd hanging around. This > >> makes for really twisty and perplexing bugs. > > >> So I don't want to do that, but I can't figure out for the life of me > >> how to get a hold of all filehandles associated with an fd, or to > >> close all filehandles associated with an fd. Is there a way to do > >> this? I tried walking through the symbol tables, but that won't get > >> lexically scoped and localized filehandles. How does one do this? > > >> BTW, at this moment I'm looking through perlio.c to try to see how the > >> filehandles and fd's are managed internally. If I had to I could > >> write a c routine to do this and expose it through XS. Any clues in > >> this area though, would be nice (like is there something already in > >> perlio.c to do this (-:). > > >> And of course pointing me to a more appropriate list is fine too. > > >> Thanks...james > > > All daemons should periodically kill themselves and restart. This will: > > Shawn good point. Do you know a way to handle the initial fd leak > upon first fork? Remember this is a library that handles > daemonization for some unknown program. The goal is to close all > filed descriptors except the ones they tell me not close (or to not > close them at all if they specify this). This is actually as much a > security feature as anything. Right now though, being in this library > I don't know of any means to figure out without them telling what > FileHandles have been opened before calling my daemonize function. Is > there a way to do this? or a way to get the FileHandles from the fd?
The forked process could exec itself to close fd's higher than $^F (ordinarily 2) for the initial leak. But I suspect there's no easy way to close fd's more selectively. -- Charles DeRykus -- To unsubscribe, e-mail: beginners-unsubscr...@perl.org For additional commands, e-mail: beginners-h...@perl.org http://learn.perl.org/
