How do I delete all but 10 newest files in Linux?

Question

I'm trying to keep a directory full of log files manageable. Nightly, I want to delete all but the 10 most recent. How can I do this in a single command?

Answer 1

From here:

#! /bin/sh
# keepnewest
#
# Simple directory trimming tool to handle housekeeping
# Scans a directory and deletes all but the N newest files
#
# Usage: cleanup <dir> <number of files to keep>
#
# v 1.0 Piers Goodhew 1/mar/2007. No rights retained.


if [ $# -ne 2 ]; then
  echo 1>&2 "Usage: $0 <dir> <number of files to keep>"
  exit 1
fi

cd $1
files_in_dir=`ls | wc -l`
files_to_delete=`expr $files_in_dir - $2`
if [ $files_to_delete -gt 0 ]; then
  ls -t | tail -n $files_to_delete | xargs rm
  if [ $? -ne 0 ]; then
    echo "An error ocurred deleting the files"
    exit 1
  else
    echo "$files_to_delete file(s) deleted."
  fi
else
  echo "nothing to delete!"
fi

Answer 2

bash:

ls -1t | (i=0; while read f; do
  if [ $i -lt 10 ]; then
    ((i++))
    continue
  else
    rm -f "$f"
  fi
done)

This skips the 10 newest als deletes the rest. logrotate may be better, I just want to correct the wrong shell related answers.

Answer 3

For a portable and reliable solution, try this:

ls -1tr | head -n -10 | xargs -d '\n' rm -f

The tail -n -10 syntax in one of the other answers doesn't seem to work everywhere (i.e., not on my RHEL5 systems).

And using $() or `` on the command line of rm runs the risk of

1. splitting file names with whitespace, and
2. exceeding the maximum commandline character limit.

xargs fixes both of these problems because it'll automatically figure out how many args it can pass within the character limit, and with the -d '\n' it will only split at the line boundary of the input. Technically this can still cause problems for filenames with a newline in them, but that's far less common than filenames with spaces, and the only way around the newlines would be a lot more complicated, probably involving at least awk, if not perl.

If you don't have xargs (old AIX systems, maybe?) you could make it a loop:

ls -1tr | head -n -10 | while read f; do
  rm -f "$f"
done

This will be a bit slower because it spawns a separate rm for each file, but will still avoid caveats 1 and 2 above (but still suffers from newlines in file names).

Answer 4

The code you'd want to include in your script is

 rm -f $(ls -1t /path/to/your/logs/ | tail -n +11)

The -1 (numeric one) option prints each file on a single line, to be safe. The -f option to rm tells it to ignore non-existent files for when ls returns nothing.

Answer 5

A tool like logrotate does this for you. It makes log management much easier. You can also include additional cleanup routines shuch as halo sugggested.