Deleting old directory

Question

I am trying to add a way to remove backups older than 3 days ago in my script.

See below a stripped down simplified version, which just leaves the removal part.

It was my understanding that ${BACKUP_DEST[$i]}/$OLDBACKUP should be outputting something like '/Users/christopherdavies/Desktop/rsync/test1.co.uk/07-06-18'.

However, each time this runs, it deletes the folder above, of 'test1.co.uk', and regardless if it 3 days old or not.

Is anyone able to point me in the right direction? I haven't been able to make any headway... fresh pair of eyes?

#!/bin/sh

WEBSITE_HOST=(
    "[email protected]"
    "[email protected]"  
)

BACKUP_DEST=(
    "/Users/christopherdavies/Desktop/rsync/test1.co.uk"
    "/Users/christopherdavies/Desktop/rsync/test2.co.uk"
)

OLDBACKUP=`date -d "3 days ago" +"%d%m%Y"`

SITE_COUNT=${#WEBSITE_HOST[@]}

for (( i = 0; i < SITE_COUNT; i++ )); do

    # Remove old backups    
    if [ -d "${BACKUP_DEST[$i]}/$OLDBACKUP" ]; then rm -Rf ${BACKUP_DEST[$i]}/$OLDBACKUP; fi

done
exit 0

Answer 1

The date utility on macOS (which I presume you're using judging from the location of the user home directories) is not GNU date and therefore does not support all its features.

This means that you OLD_BACKUP variable will be empty (and you ought to see an error message when date is run), which in turn means that it's the ${BACKUP_DEST[$i]} directory that gets deleted.

Instead, you may use date -v -3d +'%d-%m-%Y'.

#!/bin/bash

set -e

backup_dest=(
    '/Users/christopherdavies/Desktop/rsync/test1.co.uk'
    '/Users/christopherdavies/Desktop/rsync/test2.co.uk'
)

when=$( date -v -3d +'%d-%m-%Y' )

for backup in "${backup_dest[@]}"; do
    [ -d "$backup/$when" ] && rm -Rf "$backup/$when"
done

Alternatively, install GNU coreutils and use GNU date.

Other changes made to your code:

• Removed exit 0 from the end and added set -e. If the script fails, you will want to be able to notice it.

• The website array was not used.

• Loop over the items in the array rather than using indexes, it's easier to read.

• If you want a single line simple if statement, you may use short circuit syntax instead (which is shorter).

• Use lower-case variable names.

• Always quote variable expansions.

• It's a bash script, so it should reference bash on the #!-line.