Shell script to count files, then remove oldest files

Question

I am new to shell scripting, so I need some help here. I have a directory that fills up with backups. If I have more than 10 backup files, I would like to remove the oldest fi

Answer 1

Using inode numbers via stat & find command (to avoid pesky-chars-in-file-name issues):

stat -f "%m %i" * | sort -rn -k 1,1 | tail -n +11 | cut -d " " -f 2 | \
   xargs -n 1 -I '{}' find "$(pwd)" -type f -inum '{}' -print

#stat -f "%m %i" * | sort -rn -k 1,1 | tail -n +11 | cut -d " " -f 2 | \
#   xargs -n 1 -I '{}' find "$(pwd)" -type f -inum '{}' -delete 

Answer 2

Straightforward file counter:

max=12
n=0
ls -1t *.dat |
while read file; do
    n=$((n+1))
    if [[ $n -gt $max ]]; then
        rm -f "$file"
    fi
done

Answer 3

Based on others suggestions and some awk foo, I got this to work. I know this an old thread, but I didn't find a decent answer here and this sorted it for me. This just deletes the oldest file, but you can change the head -n 1 to 10 and get the oldest 10.

find $DIR -type f -printf '%T+ %p\n' | sort | head -n 1 | awk '{first =$1; $1 =""; print $0}' | xargs -d '\n' rm

Answer 4

Make sure your pwd is the correct directory to delete the files then(assuming only regular characters in the filename):

ls -A1t | tail -n +11 | xargs rm

keeps the newest 10 files. I use this with camera program 'motion' to keep the most recent frame grab files. Thanks to all proceeding answers because you showed me how to do it.

Answer 5

I like the answers from @Dennis Williamson and @Dale Hagglund. (+1 to each)

Here's another way to do it using find (with the -newer test) that is similar to what you started with.

This was done in bash on cygwin...

if [[ $(ls /backups | wc -l) > 10 ]]
then
  find /backups ! -newer $(ls -t | sed '11!d') -exec rm {} \;
fi

Answer 6

find is the common tool for this kind of task :

find ./my_dir -mtime +10 -type f -delete

EXPLANATIONS

• ./my_dir your directory (replace with your own)
• -mtime +10 older than 10 days
• -type f only files
• -delete no surprise. Remove it to test your find filter before executing the whole command

And take care that ./my_dir exists to avoid bad surprises !