Re: NSFileManager destroying target of symlink at changefileattributes

FROM : thomas bauer
DATE : Sun Nov 18 22:29:23 2007

dear list,

sorry. in my confustion i forgot the question (although obvious):

what is going on? why cannot i use a modified copy of attributes
on the target symlink file?
how am i supposed to modify a symlinks attributes?
is writing of attributes to symlinks not supported by nsfilemanager?
any hint is appreciated....

regards
thomas bauer

Begin forwarded message:

> From: thomas bauer <<email_removed>>
> Date: 18. November 2007 20:39:29 GMT+01:00
> To: <email_removed>
> Subject: NSFileManager destroying target of symlink at 
> changefileattributes
>
> dear list,
>
> following code is executed as root in a test foundation tool.
> it simply copies the localtime symlink (/etc/localtime) to another 
> partition and then tries to clone
> its fileattributes. if a copy of the source fileattributes 
> dictionary is used
> instead of the original one, the changefileattributes call damages 
> the target
> of the symlink replacing it with a broken symlink.
>
> (ie /usr/share/zoneinfo/yourzone will be damaged, destroying your 
> timezone setting.
> make a copy before testing this!)
>
> if the original dict is used, everything is fine.
> i nslogged both dicts and both are identical.
>
> (only in this example code i use a trivial copy of the attributes 
> dict. the original code has to use
> a mutable copy to alter the permission flags between source and 
> target. since this modification
> is not related to the issue i have altered the testcode to just use 
> a trivial copy)
>
> thanks and regards
> thomas bauer - freeridecoding
>
>
> #import <Foundation/Foundation.h>
>
> int main (int argc, const char * argv[]) {
>  NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];
>
>     NSFileManager *fm = [NSFileManager defaultManager];    
>     [fm copyPath:@"/private/etc/localtime" toPath:@"/Volumes/tigerclone/
> localtime" handler:nil];
>
>     NSDictionary *sourceAttributes = [fm fileAttributesAtPath:@"/
> private/etc/localtime" traverseLink:NO];
>     NSDictionary *copyattrs= [NSDictionary 
> dictionaryWithDictionary:sourceAttributes];
>     
>     // [fm changeFileAttributes:copyattrs atPath:@"/Volumes/tigerclone/
> localtime"];    // THIS BREAKS TARGET OF SOURCE SYMLINK
>     [fm changeFileAttributes:sourceAttributes atPath:@"/Volumes/
> tigerclone/localtime"];    //THIS IS OK
>
>     [pool release];
>  return 0;
> }
>
> d
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