Delete files older than x minutes/horus/days/etc.

riahc3 · 03-27-2017, 06:01 AM

Im currently running a script that creates two files inside a folder each time it runs.

hello($timestamphere).sql at 1020
hellolog($timestamphere) at 1021

And so on.

Id like to make a modification and if it counts the files inside the folder and it is 30, the oldest two ones should be deleted to keep things clean.

How can I do this?

Thank you

kilgoretrout · 03-27-2017, 07:00 AM

Just to get you started, this will show you how to get the number of files in the current directory:

http://tldp.org/HOWTO/Bash-Prompt-HOWTO/x700.html

And this will show you how to find the oldest file in a directory tree:

https://superuser.com/questions/5526...directory-tree

Then it's just a matter of setting up a do loop for the condition you want and deleting the files you want.

sundialsvcs · 03-27-2017, 07:16 AM

Perhaps the logrotate utility is just what the doctor ordered.

It can automatically compress old files, and delete them after a certain time, and do a great many other useful things. It can be applied to any directory(ies) anywhere.

riahc3 · 03-27-2017, 09:37 AM

Does this look good?:

Code:

#!/bin/bash
count=`ls -1 /path/to/your/directory | wc -l`
if [ $count -ge 30 ]
then
for file in $( ls -lt /path/to/your/directory | tail -n 2)
do
    echo "Deleting File $file"
    rm $file
done
fi

pan64 · 03-27-2017, 09:47 AM

if that works for you....

But actually it is not really good:
1. do not use:
for file in $(whatever command)
because that is unsafe, you need to use:

Code:

while read file
do
....
done << $(command)

2. do not need loop at all
rm $( ls -lt /path/to/your/directory | tail -n 2)
should also work without any loop, but probably that is unsafe too

RandomTroll · 03-27-2017, 03:22 PM

'test' can compare files by date. When I want to do what you're doing, I create a file with the relevant date, using

Code:

touch -tTheDate TimeComparisonFile

then act on all files newer or older than that file's date.

Code:

for file in *
do
if [ $file -ot TimeComparisonFile ]
then
rm $file
fi
done

I think it odd that test can't compare a file to an actual date, but that's the way I read the man page.

Note that TheDate has to include minutes and seconds, for example 201703271237 would be 12:37 on 2017 March 27.

riahc3 · 04-19-2017, 02:21 AM

Quote:

Originally Posted by pan64

if that works for you....

But actually it is not really good:
1. do not use:
for file in $(whatever command)
because that is unsafe, you need to use:

Code:

while read file
do
....
done << $(command)

2. do not need loop at all
rm $( ls -lt /path/to/your/directory | tail -n 2)
should also work without any loop, but probably that is unsafe too

Your code makes no sense, sorry.

Could you please post the correct and "safe" code?

riahc3 · 04-20-2017, 04:41 AM

Nothing?

riahc3 · 04-24-2017, 02:16 AM

Noone can lend a hand?

pan64 · 04-24-2017, 02:22 AM

you did not accept ....

riahc3 · 04-24-2017, 03:04 AM

Quote:

Originally Posted by pan64

you did not accept ....

Did not accept what?

RandomTroll · 04-25-2017, 12:34 AM

Mr riach3:

I do not understand what Mr pan64 means either. I recommend that you stop trying to understand his answer and pursue an alternative.

Code:

rm `ls -t | tail -2`

works if there are no other files in the directory; if the files have a unique feature to their name, that can be used in the 'ls'

riahc3 · 04-25-2017, 02:33 AM

Quote:

Originally Posted by RandomTroll

Mr riach3:

I do not understand what Mr pan64 means either. I recommend that you stop trying to understand his answer and pursue an alternative.

Code:

rm `ls -t | tail -2`

works if there are no other files in the directory; if the files have a unique feature to their name, that can be used in the 'ls'

Sure Im open to alternatives as long as they work 100%

Like I said the files will be

file201604182100
filelog201604182100
file201604182200
filelog201604182200
file201604182300
filelog201604182300

And so on. When it reaches 30, it should delete the last oldest set.

TB0ne · 04-25-2017, 07:02 AM

Quote:

Originally Posted by riahc3

Sure Im open to alternatives as long as they work 100% Like I said the files will be

file201604182100
filelog201604182100
file201604182200
filelog201604182200
file201604182300
filelog201604182300

And so on. When it reaches 30, it should delete the last oldest set.

Pan64 is saying "We did try to give you a hand, but you didn't accept it". riahc3, don't bump your own threads after short times, or at ALL, unless you're adding more information. You were given two links in the first reply which told you how to find the oldest files, and how to write a bash script. What, then, is preventing you from actually writing your own script?? We aren't going to 'correct' your code for you, nor post you the "work 100%" solution. Read the "Question Guidelines" link.

We are happy to HELP you with what you have personally written/done...so post that, or tell us what error(s) you're getting with what you did write. You posted a script..did you try to modify it according to what pan64 told you? Did you try to actually RUN what you wrote, to see if it worked? It's up to you to test/write your own scripts....

RandomTroll · 04-25-2017, 10:35 PM

Quote:

Originally Posted by riahc3

the files will be

file201604182100
filelog201604182100
file201604182200
filelog201604182200
file201604182300
filelog201604182300

And so on. When it reaches 30, it should delete the last oldest set.

Code:

if [ `ls file* | grep -c file` -eq 30 ]
then
rm `ls -t file* | tail -2`
fi

will delete the 29th-oldest and 30th-oldest files named file* when there are 30 files named file*. If you know there will always be 30, you can do without the test.

If there are non-target files of the form file*, this won't work, you'll need extra information to distinguish the target files from innocent bystanders.