🌱 Remove old files

ls -r1 $PT_MYSQLBACKUPPATH/ | tail +$(($PT_FILESTOKEEP+1)) | xargs rm

1. ls -r1 will list all files in reverse order, one file per line.
2. tail +$number filters the first $number-1 files of the list out (resp. displays all files beginning from $number till the last one).
3. xargs will execute rm with all file names from standard input.