Delete all but 1000 random files in a directory

Delete all but 1000 random files in a directory

Code:

find /path/to/dir -type f -print0 | sort -zR | tail -zn +1001 | xargs -0 rm

Explanation:

1. List all files in /path/to/dir with find;
   • print0: use \0 (null character) as the line delimiter; so file paths containing spaces/newlines don't break the script
2. Shuffle the file list with sort;
   • -z: use \0 (null character) as delimiter, instead of \n (a newline)
   • -R: random order
3. Strip first 1000 lines from the randomized list with tail;
   • -z: treat the list as zero-delimited (same as with sort)
   • -n +1001: show lines starting from 1001 (ie. omit first 1000 lines)
4. xargs -0 rm - remove the remaining files;
   • -0: zero-delimited, again

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Why it's better than quixotic's solution*:

1. Works with filenames containing spaces/newlines.
2. Doesn't try to create any directories (which may already exist, btw.)
3. Doesn't move any files, doesn't even touch the 1000 "lucky files" besides listing them with find.
4. Avoids missing a file in case the output of find doesn't end with \n (newline) for some reason.

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* - credit to quixotic for | sort -R | head -1000, gave me a starting point.