Re: Path from NSFileHandle?
Re: Path from NSFileHandle?
- Subject: Re: Path from NSFileHandle?
- From: Erg Consultant <email@hidden>
- Date: Wed, 8 Apr 2009 21:55:12 -0700 (PDT)
Unfortunately I can't do that as my class are wrappers around the ANSI file I/O calls such as fopen, etc. - so I have to match their prototypes.
________________________________
From: Adam R. Maxwell <email@hidden>
To: cocoa-dev Users <email@hidden>
Sent: Wednesday, April 8, 2009 9:11:00 PM
Subject: Re: Path from NSFileHandle?
On Apr 8, 2009, at 8:54 PM, Michael Ash wrote:
> On Wed, Apr 8, 2009 at 11:00 PM, Erg Consultant
> <email@hidden> wrote:
>> Is there a way to get the path of a file opened by an NSFileHandle from the file handle itself? I have a method that takes only an NSFileHandle to an open file but I don't know the file's path.
>
> Basically, you can't. An NSFileHandle is basically just a wrapper
> around a UNIX file descriptor. A file descriptor might not even *have*
> a path. For example, it might reference a pipe or network socket. If
> it references a file, it might reference a file which has been
> deleted. It could also reference a file with multiple hard links,
> meaning that it would have *multiple* paths.
>
> It is possible to find this information if you *really* want to. The
> fstat() call (use the -fileDescriptor method to get the file
> descriptor to pass to it) will give you the device and inode number of
> the file, if it has one. You can then search that device for a file
> with that inode. But this will be slow, and again it might not even
> exist.
I recently noticed that you can use F_GETPATH with fcntl(2), but I've no idea what caveats are associated with it. It might be easier than messing with inodes directly, anyway?
> Your best bet is to modify your code to pass the path to where it's needed.
Definitely, or just figure out a way to use the NSFileHandle directly...
--Adam
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