[SOLVED] Can a file's timestamp be auto-updated when moved to a directory?

mfoley · 09-19-2018, 11:04 AM

I have a dropbox directory accessible from the web. I also have a cron script that deletes anything in this folder if more than 7 days old.

The problem is that if someone puts a file into this directory that is already 7+ days old it gets deleted immediately.

Is there a way to auto-touch the timestamp on a file when moved to a directory?

hydrurga · 09-19-2018, 11:12 AM

You could always create a subdirectory of that main Dropbox directory and use a cron script to check the main directory for files and move them to the subdirectory, touching the filestamp as you move then. Your second purging cron script would then work only on the subdirectory.

mfoley · 09-19-2018, 11:35 PM

Yeah, that's basically what I did. I hoped there might be some secret tool I didn't know about. Here's my script:

Code:

. /etc/profile.d/tomcat.sh
DROPDIR="$CATALINA_HOME/webapps/ohprs/dropbox"
CURFILES=`find ${DROPDIR} -type f | sort`

# If our previous list is missing, use the current list

if [ ! -e /root/.dropfiles ]
then
    echo reset .dropfiles
    echo "$CURFILES" >/root/.dropfiles
    exit
fi

# Compare old and new

find ${DROPDIR} -type f | sort | comm -13 /root/.dropfiles - | \
while read
do
    echo `date "+%Y-%m-%d %H:%M"` touching "$REPLY"
    touch "$REPLY"
done

# Reset list
echo "$CURFILES" >/root/.dropfiles

exit 0

This is run from cron every minute between 7:00AM and 6:00PM, Monday through Friday. It doesn't do the purging since there is another job that does that for this and many other temp files. I run this one minutely since the other purging script runs periodically as well.

MadeInGermany · 09-20-2018, 12:50 AM

You can save one find run:

Code:

# Compare old and new

echo "$CURFILES" | comm -13 /root/.dropfiles - | \
while read
do

Furthermore, maybe you can improve your deletion job, by considering atime and/or ctime in addition to the mtime? Or by skipping file deletion in directories with a recent mtime?

Turbocapitalist · 09-20-2018, 01:02 AM

Quote:

Originally Posted by mfoley

Is there a way to auto-touch the timestamp on a file when moved to a directory?

incron, as opposed to cron, can be configured to trigger your script whenever a file is added to a watched directory. Whether that works with Dropbox's directory, I don't know but you could give it a test.

rknichols · 09-20-2018, 08:38 AM

You could base your deletion on ctime rather than mtime. The ctime stamp does get updated when a file is moved.

mfoley · 09-21-2018, 02:45 PM

Quote:

Originally Posted by MadeInGermany

You can save one find run:

Code:

# Compare old and new

echo "$CURFILES" | comm -13 /root/.dropfiles - | \
while read
do

Yes, I actually saw that after I posted, but was too lazy to change it. I wondered if anyone would catch that ... and someone did!

Quote:

Originally Posted by Turbocapitalist

incron, as opposed to cron, can be configured to trigger your script whenever a file is added to a watched directory. Whether that works with Dropbox's directory, I don't know but you could give it a test.

Excellent! That exactly the "magic tool" I was looking for. I'll experiment with that.

Quote:

Originally Posted by rknichols

You could base your deletion on ctime rather than mtime. The ctime stamp does get updated when a file is moved.

Also an excellent suggestion!

I'll try both of these ideas. Thanks.

crts · 09-21-2018, 06:12 PM

Quote:

Originally Posted by mfoley

Excellent! That exactly the "magic tool" I was looking for. I'll experiment with that.

I used 'incrond' many years ago. Here is a small pseudo-mini-tutorial that I made in another thread.

It might give you a quick overview of how 'incron' is set up. In the example it was used to change the permissions of a newly created file. Of course, you should change the corresponding command to, e.g.,

Code:

path/to/directory/you/want/observed IN_CREATE touch $@/$#

Let me know if there were same significant changes; as I said, it has been some time since I used it.

PS:
Related documentation:
https://linux.die.net/man/5/incrontab
https://linux.die.net/man/5/incron.conf
https://linux.die.net/man/8/incrond