use Perl

• Use the source, Luke (Score:4, Informative)

  by samtregar (2699) on 2003.09.15 12:11 (#24199) Homepage Journal

  How does ps get its data? Maybe looking at the source for OpenBSD ps would be useful...

  -sam

  Reply to This

  • Re:Use the source, Luke (Score:2)

    by djberg96 (2603)

    Without looking, my guess would be that it uses the kvm libs. However, ps (and most of your other installed programs) run suid root, so it *does* have permission to read /dev/mem.
    • Re:Use the source, Luke (Score:2)

      by Dom2 (2981)

      I would have thought that most BSDs use -lkvm, plus setgid kmem or something. I have a feeling that newer FreeBSD uses sysctl however. Yup, libkvm appears to do that.

      Don't forget that BSD ps also doesn't /proc so that you can get ps to run over a crashdump image.

      -Dom
• No /proc on OpenBSD (Score:3, Informative)

  by merlyn (47) <merlyn@stonehenge.com> on 2003.09.15 13:04 (#24200) Homepage Journal

  The Proc filesystem is a Linux-ism. Not in the BSD family, that I'm aware of.

  --
  

  • Randal L. Schwartz
  • Stonehenge

  Reply to This

  • Re:No /proc on OpenBSD (Score:2)

    by djberg96 (2603)

    It exists in the BSD family but it's often not mounted by BSD admins, which probably led you to believe that. Also, Solaris has /proc, but it's not in plain text format. Of the *nix flavors that I've seen so far, only HP-UX doesn't have a proc filesystem, but I certainly haven't seen them all.
    • Re:No /proc on OpenBSD (Score:2)

      by jhi (318)

      What is the license of top(1)? That would have reams of scary kernel-groping code exactly for this purpose.
      
    • Re:No /proc on OpenBSD (Score:2)

      by merlyn (47)

      OK, I overstepped by saying "BSD family". But it is specifically not in OpenBSD, hence the subject of this post and the previous replies. There's no manpage for it. There's no option to "mount" it by the "admin". It doesn't exist.

      --
      

      • Randal L. Schwartz
      • Stonehenge
      • Re:No /proc on OpenBSD (Score:2)

        by djberg96 (2603)

        Yes and no. It *can* exist. It seems (so the guy who gave me the account tells me) that you have to create a /proc partition (and give it a bit of space), then mount it.

        Anyway, I have an account on an OpenBSD box and I can see process info under /proc now.
  • Re:No /proc on OpenBSD (Score:1)

    by jordan (120)

    I think that /proc was first seen in Plan 9 and then other Unix-like operating systems copied it.