I had written some log pruning scripts, but they weren't working 100%; the first script found everything older than 7 days and gzip'd them, the second script found everything older than 31 days and rm'd them. The intent was to find anything that hadn't been modified (logged to) in that period, but because I was testing ctime it was using the date that I gzip'd them and not being aggressive enough.

My old copy of O'Reilly's Unix in a Nutshell describes ctime (under the find command) as "more inclusive than mtime or atime", but that's both vague and inaccurate.

ctime is really the last time the inode was modified, whereas mtime covers when the data/content was modified and atime when it was last accessed (read). gzip modifies the inode but doesn't really change the data, so my script was all dorked up.

I got passed a post from an apache spam list which gave a much better run-down; I also managed to find a quick comparison tonight. I can't see many real uses for ctime, since usually you're looking for changes to the data, covered by mtime.

Microsoft has announced that they are opening the XML schema for Visio 2003. The Cover Pages has a bit more in-depth picture of what this means. It would be great if we could finally have an F/OSS which can handle Visio diagrams; currently, I have to get someone with a Windows copy to export it as a PNG.