cp -u
Hi! I'm using Ubuntu version 8.04, kernel 2.6.24-19-generic. I have done some simple backups of directories using 'cp -u' that updates the files, if source is newer than the destination (or if destination file is missing). I noticed that if, for some reason, the copy of a file is interrupted (and so the destination file is not the same size as the source) and after that you do 'cp -u' again it does not update the interrupted file. So the 'cp -u' does not care about the file size mismatch and cares only about the timestamps. So I would like to suggest that 'cp -u' should also check the size of the files and do a copy if source is newer, or if destination is missing, or if file sizes are different. Regards, Markku A. Mähönen ___ Bug-coreutils mailing list Bug-coreutils@gnu.org http://lists.gnu.org/mailman/listinfo/bug-coreutils
Re: cp -u
2008/6/14 Philip Rowlands [EMAIL PROTECTED]: You might find rsync to be a better tool for this task. It's more robust against partial-copy failures, and has the nice property that copied files will all carry the same mtime, whereas cp -u will not attempt to replicate timestamps (from a cursory check). Ok, rsync might be better for this task (it seems to be quite a cpu hog though). But if you forget that, imho the 'cp -u' does not work as it should, so it is a bug. Cheers, Markku ___ Bug-coreutils mailing list Bug-coreutils@gnu.org http://lists.gnu.org/mailman/listinfo/bug-coreutils
Re: cp -u
2008/6/14 Bob Proulx [EMAIL PROTECTED]: Therefore the caller *must* check the exit code and handle errors appropriately if it cares about them. I suspect that your backup script is not checking the exit code from cp and therefore not handling the original interrupt condition. You don't get the exit code, if the system boots while 'cp -u' /M ___ Bug-coreutils mailing list Bug-coreutils@gnu.org http://lists.gnu.org/mailman/listinfo/bug-coreutils
Re: cp -u
2008/6/14 Bob Proulx [EMAIL PROTECTED]: Markku A. Mähönen wrote: You don't get the exit code, if the system boots while 'cp -u' At that point the computational model of the machine is broken and there isn't anything that will protect you against file corruption. But you mentioned interrupted and therefore normal SIGINT came to mind. There is a way to protect against file corruption: check the file sizes, as I was suggesting previously. rsync is not an answer to failing 'cp -u' Cheers, Markku ___ Bug-coreutils mailing list Bug-coreutils@gnu.org http://lists.gnu.org/mailman/listinfo/bug-coreutils
