Bdtyktl

I backup .mozilla every (re)boot to a folder ~/nas-backups/mozilla but I only want to keep the most recent 10 folders alphabetically. The backups are stored with a date stamp e.g. .mozilla_2018_11_05_08:13

I want to delete all but the most recent 10 as part of a script but as they are hidden files I can not find a way to do it:

rm -R 'ls -t | tail -n +11' as it ignores hidden files/folders.

I have tried rm -R 'ls -ta | tail -n +11' but that doesn't work either.

If it could be expanded so it only kept the first backup of each day that would be a bonus.

May I request an explanation of any suggestions? Thanks.

Any help please?

• Not for names with spaces or newline characters.




• OK in your case where the names are like ".mozilla_2018_11_05_08:13 ".




• I presumed that there are no other files or folders in the mother folder ~/nas-backups/mozilla



• 
  

  Tested it before posting:

  
  
  

  cd ~/nas-backups/mozilla
  
  total=$(ls -1A|wc -l); remove=$((total - 10)); rm -rv $(ls -1vA|head -n $remove)
  
  

  
  

explaination

total=$(ls -1A|wc -l) #total number of folders

remove=$((total - 10)) #total -10 so that 10 folders are not removed

rm -rv $(ls -1vA|head -n $remove) # removes total -10 from top(head)

# because older folders(by name) are first in ls -1vA (v switch lists the names 

# proper numeric order.

ls --help

-v natural sort of (version) numbers within text

Example:

:~/nas-backups/mozilla$ ls -1vA

.mozilla_2019_01_09_01:16

.mozilla_2019_01_09_18:12

.mozilla_2019_01_09_18:16

.mozilla_2019_01_09_19:16

.mozilla_2019_01_09_20:16

.mozilla_2019_01_10_01:16

.mozilla_2019_01_10_18:12

.mozilla_2019_01_10_18:16

.mozilla_2019_01_10_19:16

.mozilla_2019_01_10_20:16

.mozilla_2019_02_09_02:16

.mozilla_2019_02_09_18:12

.mozilla_2019_02_09_18:16

.mozilla_2019_02_09_19:16

.mozilla_2019_02_09_20:16

.mozilla_2019_03_09_03:16

.mozilla_2019_03_09_18:12

.mozilla_2019_03_09_18:16

.mozilla_2019_03_09_19:16

.mozilla_2019_03_09_20:16

.mozilla_2019_03_10_03:16

.mozilla_2019_03_10_18:12

.mozilla_2019_03_10_18:16

.mozilla_2019_03_10_19:16

.mozilla_2019_03_10_20:16

:~/nas-backups/mozilla$ total=$(ls -1A|wc -l); remove=$((total - 10)); rm -rv $(ls -1vA|head -n $remove)

removed directory '.mozilla_2019_01_09_01:16'

removed directory '.mozilla_2019_01_09_18:12'

removed directory '.mozilla_2019_01_09_18:16'

removed directory '.mozilla_2019_01_09_19:16'

removed directory '.mozilla_2019_01_09_20:16'

removed directory '.mozilla_2019_01_10_01:16'

removed directory '.mozilla_2019_01_10_18:12'

removed directory '.mozilla_2019_01_10_18:16'

removed directory '.mozilla_2019_01_10_19:16'

removed directory '.mozilla_2019_01_10_20:16'

removed directory '.mozilla_2019_02_09_02:16'

removed directory '.mozilla_2019_02_09_18:12'

removed directory '.mozilla_2019_02_09_18:16'

removed directory '.mozilla_2019_02_09_19:16'

removed directory '.mozilla_2019_02_09_20:16'

Try this:

ls -tA|tail -n +11|xargs rm -R

This deletes all but the latest 10 files or folders (by file modification time) in a simple one-liner.

ls -tA lists all files including hidden ones, but without the . and .. special files, sorted by modification time (newest first).

tail -n +11 then takes only those files starting from the 11th entry (i.e. all but the 10 newest).

xargs just takes the output from tail and uses it as arguments to rm (executing rm once for each line from tail). Useful for commands that don't work with a simple pipe.