CODEWITHSUNDEEP
unixtar
Sami
Sami

Reputation: 765

Unix : how to tar only N first files of each folder?

I have a folder containing 2Gb of images, with sub-folders several levels deep.

I'd like to archive only N files of each (sub) folder in a tar file. I tried to use find then tail then tar but couldn't manage to get it to work. Here is what I tried (assuming N = 10):

find . | tail -n 10 | tar -czvf backup.tar.gz

… which outputs this error:

Cannot stat: File name too long

What's wrong here? thinking of it - even if it works I think it will tar only the first 10 files of all folders, not the first 10 files of each folder.

How can I get the first N files of each folder?

Upvotes: 4

Views: 797

Answers (1)

sjnarv
sjnarv

Reputation: 2384

A proposal with some quirks: order is only determined by the order out of find, so "first" isn't well-defined.

find . -type f |
awk -v N=10 -F / 'match($0, /.*\//, m) && a[m[0]]++ < N' |
xargs -r -d '\n' tar -rvf /tmp/backup.tar

gzip /tmp/backup.tar

Comments:

  1. use find . -type f to ensure that files have a leading directory-name prefix, so the next step can work
  2. the awk command tracks such leading directory names, and emits full path names until N (10, here) files with the same leading directory have been emitted
  3. use xargs to invoke tar - we're gathering regular file names, and they need to be arguments to that archiving command
  4. xargs may invoke tar more than once, so we'll append (-r option) to a plain archive, then compress it after it's all written

Also, you may not want to write a backup file into the current directory, since you're scanning that - that's why this suggestion writes into /tmp.

Upvotes: 1

Related Questions