bash Cookbook

Capturing File Metadata for Recovery

Problem

You want to create a list of files and details about them for archive purposes, for example, to verify backups, re-create directories, etc. Or maybe you are about to do a large chmod -R and need a back-out plan. Or perhaps you keep /etc/* in a revision control system that does not preserve permissions or ownership.

Solution

Use GNU find with some printf formats:

#!/usr/bin/env bash
# cookbook filename: archive_meta-data

printf "%b" "Mode\tUser\tGroup\tBytes\tModified\tFileSpec\n" > archive_file
find / \( -path /proc -o -path /mnt -o -path /tmp -o -path /var/tmp \
  -o -path /var/cache -o -path /var/spool \) -prune \
  -o -type d -printf 'd%m\t%u\t%g\t%s\t%t\t%p/\n' \
  -o -type l -printf 'l%m\t%u\t%g\t%s\t%t\t%p -> %l\n' \
  -o         -printf '%m\t%u\t%g\t%s\t%t\t%p\n' >> archive_file

Warning

Note that the -printf expression is in the GNU version of find.

Discussion

The (-path /foo-o -path…) -prune part removes various directories you probably don’t want to bother with, e.g., -type d is for directories. The printf format is prefixed with a d, then uses an octal mode, user, group, and so forth. -type 1 is for symbolic links and also shows you where the link points. With the contents of this file and some additional scripting, you can determine at a high level if anything has changed, or re-create mangled ownership or permissions. Note that this does not take the place of more security-oriented programs like Tripwire, AIDE, Osiris, or Samhain.

See Also

• man find ...