How can I remove a file based on its creation date time in Perl?

Question

My webapp is hosted on a unix server using MySQL as database.

I wrote a Perl script to run backup of my database. The Perl script is inside the cgi-bin folde and it is working. I only need to set the cronjob and run the Perl script once a day.

The backups are stored in a folder named db_backups,. However, I also want to add a command inside my Perl script to remove any files inside the folder db_backups that are older than say 10 days ago.

I have searched high and low for unix commands and cannot find anything that matches what I needed.

Answer 1

You should be able to do it without resorting to Unix commands. Loop through the files in your directory, use stat on each file to get its last modify time for a file, then use unlink on the file to delete it if it's older than what you want.

Answer 2

if (-M $file > 10) { unlink $file }

or, coupled with File::Find::Rule

my $ten_days_ago = time() - 10 * 86400;
my @to_delete = File::Find::Rule->file()
  ->mtime("<=$ten_days_ago")
  ->in("/path/to/db_backup");
unlink @to_delete;

Answer 3

On Unix you can't, because the file's creation date is not stored in the filesystem.

You may want to check out stat, and -M (modification time)/-C (inode change time)/-A (access time) if you want a simple expression with relative timestamps (how long ago).

Answer 4

i have searched high and low for unix commands and cannot find anything that matches what i needed.

Check out find(1) and xargs(1). Warning: these commands may change your life at the shell prompt.

$ find /path/to/backup -type f -mtime +10 -print0 | xargs -0 echo rm -f

When you're confident that will Do What You Want (tm), remove the echo. It says, roughly, starting in /path/to/backup, descend looking for plain files whose mtime is greater than 10 days, and print their names to xargs, which will pass those names to rm in batches.

(print0 and its complement -0 are GNU extensions -- you mentioned you were on Linux -- which let you deal with whitespace in filenames safely.)