Как проверить, что копия файла - это reflink / CoW?

Когда вы набираете просто unzip, он сообщает вам

UnZip 6.00 of 20 April 2009, by Debian. Original by Info-ZIP.

Usage: unzip [-Z] [-opts[modifiers]] file[.zip] [list] [-x xlist] [-d exdir]
  Default action is to extract files in list, except those in xlist, to exdir;
  file[.zip] may be a wildcard.  -Z => ZipInfo mode ("unzip -Z" for usage).

  -p  extract files to pipe, no messages     -l  list files (short format)
  -f  freshen existing files, create none    -t  test compressed archive data
  -u  update files, create if necessary      -z  display archive comment only
  -v  list verbosely/show version info       -T  timestamp archive to latest
  -x  exclude files that follow (in xlist)   -d  extract files into exdir
modifiers:
  -n  never overwrite existing files         -q  quiet mode (-qq => quieter)
  -o  overwrite files WITHOUT prompting      -a  auto-convert any text files
  -j  junk paths (do not make directories)   -aa treat ALL files as text
  -U  use escapes for all non-ASCII Unicode  -UU ignore any Unicode fields
  -C  match filenames case-insensitively     -L  make (some) names lowercase
  -X  restore UID/GID info                   -V  retain VMS version numbers
  -K  keep setuid/setgid/tacky permissions   -M  pipe through "more" pager
See "unzip -hh" or unzip.txt for more help.  Examples:
  unzip data1 -x joe   => extract all files except joe from zipfile data1.zip
  unzip -p foo | more  => send contents of foo.zip via pipe into program more
  unzip -fo foo ReadMe => quietly replace existing ReadMe if archive file newer

Что это unzip -h, в то время как unzip -hh намного длиннее:

Extended Help for UnZip

See the UnZip Manual for more detailed help


UnZip lists and extracts files in zip archives.  The default action is to 
extract zipfile entries to the current directory, creating directories as
needed.  With appropriate options, UnZip lists the contents of archives
instead.

Basic unzip command line:
  unzip [-Z] options archive[.zip] [file ...] [-x xfile ...] [-d exdir]

Some examples:
  unzip -l foo.zip        - list files in short format in archive foo.zip 

  unzip -t foo            - test the files in archive foo

...

и если вы распаковываете файл, -h делает это:

-h Строка заголовка списка. Включает имя архива, фактический размер, общее количество файлов.