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]
tar vs cp
I've been told in the past that if you have a series of directories with subdirectories that you need to copy to another location on a disk, it is better to tar the directory, move the tarred file to the destination, and then untar it, rather than using cp to copy the directory and all of its contents. 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? Thanks, - Jamie A friend is someone who lets you have total freedom to be yourself. ___ [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]
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
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
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 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, 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
