Delete only files older than 7 days: -mtime and find

find

Found a few similar questions but were not quite a match.

I have a directory for backups (sql) and want to delete all files in that directory older then 7 days leaving any sub-directories intact.

This is what I have:

find /var/log/mbackups -mtime +7 -type f -delete

Is this the proper way to accomplish what I am after?

Best Answer

Your command will look at the top level directory /var/log/mbackups and also descend into any subdirectories, deleting files that match the seven day criterion. It will not delete the directories themselves.

If you want a command to look at files only in the /var/log/mbackups directory, and not descend into subdirectories, you need to add that restriction:

find /var/log/mbackups -maxdepth 1 -mtime +7 -type f -delete

In general you can test the find command by replacing the -delete action with something innocuous, like -print:

find /var/log/mbackups -mtime +7 -type f -print

Related Solutions

Find – Why Does find -mtime +1 Return Files Older Than 2 Days?

Well, the simple answer is, I guess, that your find implementation is following the POSIX/SuS standard, which says it must behave this way. Quoting from SUSv4/IEEE Std 1003.1, 2013 Edition, "find":

-mtime n
The primary shall evaluate as true if the file modification time subtracted
from the initialization time, divided by 86400 (with any remainder discarded), is n.

(Elsewhere in that document it explains that n can actually be +n, and the meaning of that as "greater than").

As to why the standard says it shall behave that way—well, I'd guess long in the past a programmer was lazy or not thinking about it, and just wrote the C code (current_time - file_time) / 86400. C integer arithmetic discards the remainder. Scripts started depending on that behavior, and thus it was standardized.

The spec'd behavior would also be portable to a hypothetical system that only stored a modification date (not time). I don't know if such a system has existed.

Find – How to Find and Delete Files Older Than Specific Days in Unix

You could start by saying find /var/dtpdev/tmp/ -type f -mtime +15. This will find all files older than 15 days and print their names. Optionally, you can specify -print at the end of the command, but that is the default action. It is advisable to run the above command first, to see what files are selected.

After you verify that the find command is listing the files that you want to delete (and no others), you can add an "action" to delete the files. The typical actions to do this are:

-exec rm -f {} \; (or, equivalently, -exec rm -f {} ';')
This will run rm -f on each file; e.g.,

rm -f /var/dtpdev/tmp/A1/B1; rm -f /var/dtpdev/tmp/A1/B2; rm -f /var/dtpdev/tmp/A1/B3; …

-exec rm -f {} +
This will run rm -f on many files at once; e.g.,
```
rm -f /var/dtpdev/tmp/A1/B1 /var/dtpdev/tmp/A1/B2 /var/dtpdev/tmp/A1/B3 …
```
so it may be slightly faster than option 1. (It may need to run rm -f a few times if you have thousands of files.)
-delete
This tells find itself to delete the files, without running rm. This may be infinitesimally faster than the -exec variants, but it will not work on all systems.

So, if you use option 2, the whole command would be:

find /var/dtpdev/tmp/ -type f -mtime +15 -exec rm -f {} +

Best Answer

Related Solutions

Find – Why Does find -mtime +1 Return Files Older Than 2 Days?

Find – How to Find and Delete Files Older Than Specific Days in Unix

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