Copy preserving attributes

puterboy has asked for the wisdom of the Perl Monks concerning the following question:

I would like to copy files preserving attributes (something like cp -cdpP) within perl rather than using a system call to *nix 'cp'.

Now from the documentation of File::Copy, it seems that this module won't do that for me at least on *nix since there is no syscopy routine.

I also saw an old thread (Circa 2003) saying that since the potential attributes to be preserved are not well-defined across systems (and may change in the future), this functionality has not been implemented in CPAN.

So, I ask is that still true?

Is there any (easy) way other than forking a syscall to preserve the following attributes:

   timestamps
   ownership
   permissions
   SELinux
   Other ACL/extended attributes
[download]

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Re: Copy preserving attributes by ikegami (Patriarch) on Nov 02, 2009 at 18:10 UTC
I would like to copy files preserving attributes (something like cp -cdpP) within perl rather than using a system call to nix 'cp'.* Calling `cp` is your best option. It can be done safely with multi-arg `system` `my $rv = system('cp', '-cdpP', ...); $rv == -1 and die("Can't execute cp: $!\n"); $rv & 0x7F and die("cp died from signal ", ($rv & 0x7F), "\n"); $rv >> 8 and die("Error ", ($rv >> 8), "from cp\n");` [download]	[reply] [d/l] [select]
Re: Copy preserving attributes by thunders (Priest) on Nov 02, 2009 at 17:32 UTC
Which version of Perl and File::Copy are you using? In CPAN File::Copy does indeed provided a syscopy. Update: sorry read the docs and you are correct. On UNIX syscopy is just an alias to File::Copy::copy() Here's a thread with the same essential question.	[reply]
Re^2: Copy preserving attributes by puterboy (Scribe) on Nov 02, 2009 at 17:58 UTC
Yes - that was exactly the thread from 2003 that I was alluding to. But since it has been 6+ years, I was wondering whether there were any new approaches or solutions... One can always hope...	[reply]
Re: Copy preserving attributes by keszler (Priest) on Nov 02, 2009 at 18:24 UTC
If you want Perl to handle the attributes: stat chown chmod	[reply]
Re^2: Copy preserving attributes by puterboy (Scribe) on Nov 02, 2009 at 19:04 UTC
any solution for extended attributes/ACLs? Or is that too system specific. Also, how does the efficiency of a single cp system call compare to the code you would have to read and then set timestamp/ownership/permissions internally in perl?	[reply]
Re^3: Copy preserving attributes by JavaFan (Canon) on Nov 02, 2009 at 19:35 UTC
Considering that the running time of the 'cp' is most likely to be bound by disk I/O, I wouldn't worry about the overhead of calling 'cp'. Specially if you have the need to take care of system specifics (like extended attributes/ACLs), I would prefer calling the systems 'cp' then doing it all yourself. Specially if you don't have access to all the environments the program is supposed to run in.	[reply]
Re^4: Copy preserving attributes by gmargo (Hermit) on Nov 02, 2009 at 20:52 UTC
Re: Copy preserving attributes by zentara (Cardinal) on Nov 02, 2009 at 18:58 UTC
see Turning 0755 into rwxr-xr-x I'm not really a human, but I play one on earth. Old Perl Programmer Haiku	[reply]
Re: Copy preserving attributes by stefbv (Curate) on Nov 02, 2009 at 18:00 UTC
Maybe Sysadm::Install can do the job.	[reply]
Re: Copy preserving attributes by djp (Hermit) on Nov 03, 2009 at 09:41 UTC
I've used File-Rsync with the --archive option set to achieve this. Not the most elegant solution, but it will do what you want.	[reply]
Re^2: Copy preserving attributes by puterboy (Scribe) on Nov 03, 2009 at 23:04 UTC
Interesting idea, but I imagine that calling rsync even if coded all in Perl will be slower than a 'cp' system call.	[reply]


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