Re: Re: tar vs cp
>> tar handles symbolic links properly, whereas >> cp will "copy through" the contents of the link. > > Also true for cp -R? :-) > No, but not all systems have "cp -R", although > FreeBSD does. Likewise for the "-p" or > "--preserve-permissions" option... tar requires two executions, one to create the archive and one to remove it. This has advantages and disadvantages. cpio -p can do it in one pass, but requires that you expand the directories with find or provide a list file. Again, sometimes a good thing, sometimes not. cpio can also create a tree of links if you are on the same file system. Useful for moving large files with minimal disk activity (remove the original links afterwards). Mark Terribile __ Do you Yahoo!? The New Yahoo! Shopping - with improved product search http://shopping.yahoo.com ___ [EMAIL PROTECTED] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[EMAIL PROTECTED]"
Re: tar vs cp
On Wed, Oct 01, 2003 at 03:25:27PM -0700, Pat Lashley wrote: > --On Wednesday, October 01, 2003 13:22:36 -0400 Chuck Swiger > <[EMAIL PROTECTED]> wrote: > > >Jamie wrote: > >[ ... ] > >>I don't know what the actual rationale is for this. Can anyone > >>explain why it is oftentimes better to tar something rather than > >>using cp when copying directories and their contents? > > > >tar handles symbolic links properly, whereas cp will "copy through" the > >contents of the link. > > Another technique is 'cd /source ; find . -print | cpio -pdmv /dest'. > > But none of the built in tools seem to preserve links, flags, and > sparseness. If you want as close to a true copy as possible, check > out the cpdup port. using tar | tar instead of cp -r is usually faster because it makes more efficient use of disk I/O, because reads and writes are queued up at the same time, from the two processes) whereas cp -r reads and writes chunks sequentially (it's actually implemented using mmap'ed memory, which gains some efficiency, but it's still a sequential process because there's only one single-threaded cp running). Kris pgp0.pgp Description: PGP signature
Re: tar vs cp
--On Wednesday, October 01, 2003 13:22:36 -0400 Chuck Swiger <[EMAIL PROTECTED]> wrote: Jamie wrote: [ ... ] I don't know what the actual rationale is for this. Can anyone explain why it is oftentimes better to tar something rather than using cp when copying directories and their contents? tar handles symbolic links properly, whereas cp will "copy through" the contents of the link. Another technique is 'cd /source ; find . -print | cpio -pdmv /dest'. But none of the built in tools seem to preserve links, flags, and sparseness. If you want as close to a true copy as possible, check out the cpdup port. -Pat ___ [EMAIL PROTECTED] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[EMAIL PROTECTED]"
Re: tar vs cp
On Wed, 1 Oct 2003, Charles Swiger wrote: > On Wednesday, October 1, 2003, at 04:03 PM, Felix Deichmann wrote: > > Chuck Swiger wrote: > >> tar handles symbolic links properly, whereas cp will "copy through" > >> the contents of the link. > > > > Also true for cp -R? :-) > > No, but not all systems have "cp -R", although FreeBSD does. Likewise > for the "-p" or "--preserve-permissions" option... >From the manpage: Note that cp copies hard linked files as separate files. If you need to preserve hard links, consider using tar(1), cpio(1), or pax(1) instead. Cheers, Viktor ___ [EMAIL PROTECTED] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[EMAIL PROTECTED]"
Re: tar vs cp
On Wednesday, October 1, 2003, at 04:03 PM, Felix Deichmann wrote: Chuck Swiger wrote: tar handles symbolic links properly, whereas cp will "copy through" the contents of the link. Also true for cp -R? :-) No, but not all systems have "cp -R", although FreeBSD does. Likewise for the "-p" or "--preserve-permissions" option... -- -Chuck ___ [EMAIL PROTECTED] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[EMAIL PROTECTED]"
Re: tar vs cp
Chuck Swiger wrote: tar handles symbolic links properly, whereas cp will "copy through" the contents of the link. Also true for cp -R? :-) ___ [EMAIL PROTECTED] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[EMAIL PROTECTED]"
Re: tar vs cp
Jamie wrote: [ ... ] I don't know what the actual rationale is for this. Can anyone explain why it is oftentimes better to tar something rather than using cp when copying directories and their contents? tar handles symbolic links properly, whereas cp will "copy through" the contents of the link. -- -Chuck ___ [EMAIL PROTECTED] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[EMAIL PROTECTED]"
