<pochu> is there a way (POSIX or Hurdish) to get the corresponding file name for a fd or a hurd port? <marcusb> there is a way <pochu> marcusb: which one would that be? <marcusb> I forgot <marcusb> there is an implementation in libc <marcusb> realpath has a similar job <marcusb> but that's not what I mean <marcusb> pochu: maybe I am misremembering. But it was something where you keep looking up .. and list that directory, looking for the node with the ID of the node you had .. for <marcusb> maybe it works only for directories <marcusb> yeah <marcusb> pochu: check the getcwd() implementation of libc <marcusb> sysdeps/mach/hurd/getcwd.c <marcusb> _hurd_canonicalize_directory_name_internal * pochu looks <pochu> marcusb: interesting <pochu> though that is for dirs, and doesn't seem to be extensible to files, as you cannot lookup for ".." under a file <marcusb> right <pochu> oh you already said that :) <marcusb> actually, I am not sure that's correct <marcusb> it's probably correct, but there is no reason why looking .. up on a file couldn't return the directory it's contianed in <pochu> I don't know the interfaces or the Hurd internals very well yet, but it would look strange to me if you could do that <marcusb> the hurd is strange <pochu> it sounds like if you could `ls getcwd.c/..` to get sysdeps/mach/hurd/ :-) <marcusb> yep <pochu> ok. interesting <marcusb> you wouldn't find "ls foo.zip/.." very strange, wouldn't you? <pochu> I guess not if `ls foo.zip` listed the contents of foo.zip <marcusb> there you go <marcusb> or the other way round: would you be surprised if "cat somedir" would work? <pochu> I think so. if it did, what would it do? <marcusb> originally, cat dir would list the directory content! <marcusb> in the old unix times <pochu> I was surprised the first time I typed `vi somedir` by accident <marcusb> and some early BSDs * pochu feels young :-) <marcusb> he don't worry, I didn't see those times either <marcusb> technically, files and directories are implemented in the same way in the hurd, they both are objects implementing the fs.defs interface <marcusb> which combines file and directory operations <marcusb> of course, files and directories implement those functions differently <antrik> marcusb: do you know why this behavior (cat on directories) was changed?
* pinotree ponders about sending as RFC his patch for /proc/$pid/maps <tschwinge> Including a scheme for providing the names of mapped files? ;-D <braunr> that would be really great indeed <tschwinge> I have not yet researched how Linux does this. Perhaps store the filename used for first opening a file as a string somewhere? <pinotree> tschwinge: eh, indeed that's lacking in my patch <braunr> i'm not sure we should aim at doing it the same way <youpi> I was wondering about having interfaces for naming tasks, threads, objects <youpi> that'd be useful for debugging in general <braunr> yes <braunr> i don't think we need to take namespaces into account <braunr> a simple name or path should be quite enough <tschwinge> Agreed. "Just something!" <tschwinge> So, a Java toString() method for ports. <tschwinge> ;-) <braunr> yes <tschwinge> Oh, and could this also work recursively? The ext2fs instance on /home asks its parent fs about its own path -- can it do that? (And then cache that, most likely?) Would one get rooted filesnames that way? <braunr> i really don't think we should link it to the VFS <braunr> it should merely be a name for debugging <youpi> yep, same for me <youpi> I'd say it's the linker's task of just setting a sane name <braunr> first, keeping it isolated prevents increasing complexity <braunr> next, it doesn't reduce performance <tschwinge> youpi: Linker? <tschwinge> braunr: Ack. <braunr> yes, ld is the one creating the mappings <youpi> tschwinge: the one that loads libraries <tschwinge> Ah, for /proc/*/maps, right. I've been thinking more globally.
A related issue:
<braunr> rbraun@nordrassil:~$ vminfo $$ | wc -l <braunr> 1039 <braunr> any idea why a shell would consume more than 1039 map entries ? <braunr> (well, not more actually) <braunr> even the kernel and ext2fs have around 100 <braunr> (the kernel has actually only 23, which is very good and expected) <tschwinge> braunr: I agree that having some sort of debugging information for memory objects et al. would be quite hand. To see where they're coming from, etc. <braunr> tschwinge: this would require naming objects at the mach level <braunr> e.g. when creating an object <braunr> giving it the path of a file for example <tschwinge> braunr: I have recently seen something (due to youpi fixing a bug) that bash is doing its own memory management. Perhaps all these are such regions? <tschwinge> braunr: For example, yes. <braunr> what ? <braunr> ?! <tschwinge> braunr: http://lists.gnu.org/archive/html/bug-bash/2011-04/msg00097.html <braunr> i see
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