how to get basename in -exec of find?

I cannot get the following piece of script (which is part of a larger backup script) to work correctly:

BACKUPDIR=/BACKUP/db01/physical/incremental # Backups base directory
FULLBACKUPDIR=$BACKUPDIR/full # Full backups directory
INCRBACKUPDIR=$BACKUPDIR/incr # Incremental backups directory
KEEP=5 # Number of full backups (and its incrementals) to keep
...
FIRST_DELETE=`expr $KEEP + 1` # add one to the number of backups to keep, this will be the first deleted
FILE0=`ls -ltr $FULLBACKUPDIR | awk '{print $9}' | tail -$FIRST_DELETE | head -1` # search for the first backup to be deleted
...
find $FULLBACKUPDIR -maxdepth 1 -type d ! -newer $FULLBACKUPDIR/$FILE0 -execdir echo "removing: "$FULLBACKUPDIR/$(basename {}) \; -execdir bash -c 'rm -rf $FULLBACKUPDIR/$(basename {})' \; -execdir echo "removing: "$INCRBACKUPDIR/$(basename {}) \; -execdir bash -c 'rm -rf $INCRBACKUPDIR/$(basename {})' \;

So the find works correctly which on its own will output something like this:

/BACKUPS/db01/physical/incremental/full/2013-08-12_17-51-28
/BACKUPS/db01/physical/incremental/full/2013-08-12_17-51-28
/BACKUPS/db01/physical/incremental/full/2013-08-12_17-25-07

What I want is the -exec to echo a line showing what is being removed and then remove the folder from both directories.

I've tried various ways to get just the basename but nothing seems to be working. I get this:

removing: /BACKUPS/mysql/physical/incremental/full/"/BACKUPS/mysql/physical/incremental/full/2013-08-12_17-51-28"
removing: /BACKUPS/mysql/physical/incremental/incr/"/BACKUPS/mysql/physical/incremental/full/2013-08-12_17-51-28"
removing: /BACKUPS/mysql/physical/incremental/full/"/BACKUPS/mysql/physical/incremental/full/2013-08-12_17-25-07"

And of course the folders arn't deleted because they don't exist, just fail silently because of the -f option. If I remove the -f I get the 'cannot be found' error on each rm.

How do I accomplish this? Because backups and parts of backups may be stored across different storage systems I really need the ability to just get the folder name for use in any known path.

Solution

Lots of broken here.

All caps variables are by convention env vars and should not be used in scripts.
Using legacy backticks instead of $()
Parsing the output of ls (!)
Parsing the output of ls -l (!!!)
Expanding variables known to contain paths without full quotes.

All you absolutely need in order to improve this is to -exec bash properly, e.g.

-execdir bash -c 'filepath="$1" ; base=$(basename "$filepath") ; echo use $filepath and $base here' -- {} \;

But how about this instead:

#!/usr/bin/env bash

backup_base=/BACKUP/db01/physical/incremental
full_backup="$backup_base"/full
incremental_backup="$backup_base"/incr
keep=5
rm=echo

let n=0
while IFS= read -r -d $'\0' line ; do
    file="${line#* }"
    if [[ $n -lt $keep ]] ; then
            let n=n+1
            continue
    fi
    base=$(basename "$file")
    echo "removing: $full_backup/$base"
    "$rm" -rf -- "$full_backup"/"$base"
    echo "removing: $incremental_backup/$base"
    "$rm" -rf -- "$incremental_backup"/"$base"
done < <(find "$full_backup" -maxdepth 1 -printf '%T@.%p\0' 2>/dev/null | sort -z -r -n -t. -k1,2)

Iterate over files and directories immediately under the backup dir and skip the first 5 newest. Delete from the full and incremental dirs files matching the names of the rest.

This is an essentially safe version, except of course for timing attacks.

I have defined rm as being echo to avoid accidental deletes; swap it back to rm for actual deletion once you're sure it's correct.