• Unleaded8163@fedia.io
    3 days

    The creator of this image is Julia Evans. She’s awesome. She’s also really active on Mastodon @b0rk@jvns.ca and has a bot that posts a bunch of images similar to this one @b0rk_reruns@jvns.ca. She also sells bigger, more in-depth zines at wizardzines.com. I don’t know her personally, just think she’s great. Both of those mastodon accounts are worth following IMO.

  • state_electrician@discuss.tchncs.de
    3 days

    /proc is one of the things I keep learning about again and again. I always read about it when I don’t need it and when I would need it, I have forgotten about it.

    • 𝓹𝓻𝓲𝓷𝓬𝓮𝓼𝓼@lemmy.blahaj.zoneEnglish
      3 days

      They aren’t symbolic links. They’re closer to hard links, IIRC, in that they share the inode with other file paths.

      ofc /proc isn’t a “real” file system so the metaphors break down a little; it’s not backed by disk, it’s a view into the kernel’s process information exposed as a file system

      • trem@lemmy.blahaj.zone
        3 days

        Just to kind of confirm this:

        ls -l does not show them like hard links, but rather like soft/symbolic links.

        But when I do tail -f /path/to/file.txt on a file (to keep it open in a process) and then delete the file, I get this output in ls -l:

        3 -> '/path/to/file.txt (deleted)'

        The 3 seems to just be an incrementing number for each file opened by the process. And then, well, obviously the file isn’t now called “file.txt (deleted)”. That is just a name the kernel makes up when ls -l asks it what’s in that directory.

        So, presumably the kernel keeps a separate copy of that file in memory until the process closes the file or is terminated. And then exposes it through this pseudo-softlink rather than making use of hardlinks.

        • korthrun@piefed.socialEnglish
          3 days

          The 3 seems to just be an incrementing number for each file opened by the process.

          FWIW: https://en.wikipedia.org/wiki/File_descriptor#file_descriptor_table

          If you throw an strace on a process that interacts with the filesystem you’ll see that stuff like open() returns a file descriptor and stuff like read() takes a file descriptor as an argument.

          These are also generally the numbers you’re using when you do I/O redirection in your shell with stuff like 2>&1 or exec 5< ./some_file.txt

      • sik0fewl@piefed.caEnglish
        3 days

        Ya, the description sounds more like a hard link, but that also doesn’t work, since the executable is obviously not stored on /proc.

        Your explanation makes sense, thanks.