Clear contents of directory if 45 days old, but exclude specific subdirectory?

agi93 · 02-04-2010, 09:16 PM

I am reorganizing my home directory and have created a few subdirectories which I would like to clean out periodically. Specifically, these are ~/pkg, ~/tmp, and ~/src. I have been looking through the rm man page and googling away to try to figure this out, but I haven't been able to write a script that deletes a file 45 days old (or older) within those directories AND ignores specific subdirectories.

For ~/pkg, I just want to delete all files 45 days old or older.

For ~/tmp, I want to do the same, but leave ~/tmp/preserve and its contents completely untouched.

For ~/src, I want to also delete all files 45 days old or older, but leave ~/src/kernel and its contents completely untouched.

One possible clue to a solution is using the "find" command to locate all files that do not match the name "preserve" and delete those. It was something like

Code:

for f 'find -not -name "preserve"'
do
rm $f
end (or whatever)

I bet that script won't work at all, but the idea is that "find" will locate the desired files and then "rm" will delete them. I had a working example before, but it kept ascending to parent directories and deleting everything!

Does anyone know of a possible solution? I would like to keep a neat little script like this in ~/bin and then run it as a weekly cronjob or something. Thanks for any help!

mRgOBLIN · 02-05-2010, 01:58 AM

Code:

find . -path './preserve' -prune -o -mtime +45

Pipe it through xargs or something

wailingwailer · 02-05-2010, 02:39 AM

of course, `find` has the -delete flag, so you can probably do everything you're trying to do with a single command. just make sure you test your find flags before you go ahead with any kind of automated destruction.

agi93 · 02-05-2010, 01:30 PM

Wow, I didn't know the find command was so versatile! Right now I'm doing some experimenting with that to see if I can get something close to working like I want. Could you please explain xargs? What is the point of it and how can I use it here? The man page (at least on my mac) doesn't seem to explain why I should use it very well.

agi93 · 02-05-2010, 02:08 PM

One alternative I found that I might resort to is simply creating a directory "volatile" in my ~/ and having the subdirectories "pkg", "src", and "tmp" within those. Things I want to preserve will be kept in ~/kernel (kernel stuff) and ~/misc (other stuff). I found this find command that deletes all files x days old or older in the specified directory from http://www.howtogeek.com/howto/ubunt...days-on-linux/

It says:

Quote:

Code:

find /path/to/files* -mtime +5 -exec rm {} \;

Note that there are spaces between rm, {}, and \;

Explanation

* The first argument is the path to the files. This can be a path, a directory, or a wildcard as in the example above. I would recommend using the full path, and make sure that you run the command without the exec rm to make sure you are getting the right results.
* The second argument, -mtime, is used to specify the number of days old that the file is. If you enter +5, it will find files older than 5 days.
* The third argument, -exec, allows you to pass in a command such as rm. The {} \; at the end is required to end the command.

So I can just have a script with contents like:

Code:

#!/bin/sh
find /home/agi/volatile/pkg/* -mtime +45 -exec rm {} \;
find /home/agi/volatile/src/* -mtime +45 -exec rm {} \;
find /home/agi/volatile/tmp/* -mtime +45 -exec rm {} \;

And symlink that to /etc/cron.weekly (I'll keep it in ~/bin).

Does this script look safe/usable? I'm not on my actual Slackware box right now and I don't have any files on my Mac that are old enough that I want to clear out. Also, if ~/volatile/[pkg,src,tmp] contains subdirectories, would I substitute "rm" for "rm -r"? And I really need to know if this will ascend to the parent directories or not because I REALLY do not want it to.

Thanks for the help, everyone!

mRgOBLIN · 02-05-2010, 03:34 PM

Quote:

Wow, I didn't know the find command was so versatile! Right now I'm doing some experimenting with that to see if I can get something close to working like I want. Could you please explain xargs? What is the point of it and how can I use it here? The man page (at least on my mac) doesn't seem to explain why I should use it very well.

To save me rewriting all again... http://en.wikipedia.org/wiki/Xargs

You can test your mtime by resetting the date with touch

Code:

touch -d "46 days ago" somefile.txt

Oh and what's with the "*" at the end of your find paths? you know it will return an error if that directory is empty?

agi93 · 02-05-2010, 04:19 PM

Yes! I got this command to work:

Code:

find /home/agi/volatile/tmp -mtime +45 -exec rm {} \;

after I created a bunch of files with the touch -d command to be 46 days old and created one more brand new file to be preserved. I think a working script would then be:

Code:

#!/bin/sh
find /home/agi/volatile/pkg -mtime +45 -exec rm {} \;
find /home/agi/volatile/src -mtime +45 -exec rm {} \;
find /home/agi/volatile/tmp -mtime +45 -exec rm {} \;

I'll symlink this to /etc/cron.weekly. Hopefully, this doesn't have any bad effects (let me know if you can think of any!)

Thanks, everyone!