Re: backup-buffer-copy loops if old backup can't be deleted

[Michael Schierl]

On Wed, 22 Aug 2007 11:48:41 +0200, Martin von Gagern wrote:

> martin rudalics wrote:
>> We could check (file-writable-p to-name) here too.
> 
> And how would you combine the results? There are filesystems where I can
> delete a file even if I can't write it.

And, on lots of filesystems there are directories where you can write a
file and its directory but still not delete the file. At least on GNU/Linux
(I don't know which "half" is responsible for it), you can set a directory
to "sticky" (commonly used on /tmp) which means that only the owner (of the
file) can delete files in there.

| STICKY DIRECTORIES
| When the sticky bit is set on a directory, files in that directory may
| be unlinked or renamed only by root or their owner. Without the sticky
| bit, anyone able to write to the directory can delete or rename files.
| The sticky bit is commonly found on directories, such as /tmp, that are
| world-writable.

Michael

-- 
#!/usr/bin/perl -I' # tekscribble.pl - start in an xterm and scribble with mouse
$|=1;$g="\35";sub g{getc}sub p{print@_}system"stty -icanon";p"\233?38h";for(;;){
p"$g\33\32";$_=g;$x=g;$X=g;$y=g;$Y=g;last if/q/;$k=$y.chr((ord$Y)+64).$x.chr((
ord$X)+32);p"\33\14"if/c/;p$g.(/ì/?$l:$k).$k;$l=$k;}p"\33\3";system"stty icanon"