On Mon, Oct 30, 2006 at 10:06:53AM +1100, Peter Chubb wrote: > >>>>> "Leslie" == Leslie Katz <[EMAIL PROTECTED]> writes: > > Leslie> Michael Chesterton wrote: > Leslie> When I look at the man page for "find", I see that "-atime > Leslie> /n/" means file was last accessed /n/*24 hours ago, while > Leslie> "-ctime /n/" means file's status was last changed /n/*24 hours > Leslie> ago. However, I don't really grasp the significance of that > Leslie> difference for present purposes.
You should almost never use atime or ctime in find; mtime is almost always what you're after. In particular, atime is useless if you do backups since it will always reflect the time of the last backup or greater. > atime: When the file was last read or written to. > ctime: when the inode (metadata) was last changed. Metadata changes > that are tracked include file creation, change of ownership, > change of permissions. A nice way to see the differences is to play with the 'stat' command: $ touch eg $ stat --printf=" atime=%x\n mtime=%y\n ctime=%z\n" eg atime=2006-10-30 14:47:13.000000000 +1100 mtime=2006-10-30 14:47:13.000000000 +1100 ctime=2006-10-30 14:47:13.000000000 +1100 $ echo fish > eg # should change mtime $ stat --printf=" atime=%x\n mtime=%y\n ctime=%z\n" eg atime=2006-10-30 14:47:13.000000000 +1100 mtime=2006-10-30 14:47:35.000000000 +1100 ctime=2006-10-30 14:47:35.000000000 +1100 $ cat eg # should change atime only fish $ stat --printf=" atime=%x\n mtime=%y\n ctime=%z\n" eg atime=2006-10-30 14:48:01.000000000 +1100 mtime=2006-10-30 14:47:35.000000000 +1100 ctime=2006-10-30 14:47:35.000000000 +1100 $ $ chmod go-wr eg # should change ctime only $ stat --printf=" atime=%x\n mtime=%y\n ctime=%z\n" eg atime=2006-10-30 14:48:01.000000000 +1100 mtime=2006-10-30 14:47:35.000000000 +1100 ctime=2006-10-30 14:48:14.000000000 +1100 $ echo dog > eg $ stat --printf=" atime=%x\n mtime=%y\n ctime=%z\n" eg atime=2006-10-30 14:48:01.000000000 +1100 mtime=2006-10-30 14:48:33.000000000 +1100 ctime=2006-10-30 14:48:33.000000000 +1100 Note that ctime is always greater than or equal to mtime since mtime changes the node info, (in particular the size attribute I guess!) Matt -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html
