FreeBSD's "cp" doesn't copy extended attributes (in FreeBSD 12 currently) [のふ処|NOFUDOKORO]

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====== FreeBSD's "cp" doesn't copy extended attributes (in FreeBSD 12 currently) ======

FreeBSD's ''cp'' command doesn't copy extended attributes at all. I checked it in FreeBSD 12.0-RELEASE-p4. Thus, at this time, extended attributes attached to a file will be lost when copying the file with ''cp'' command on FreeBSD.

Someone who thinks "Use ''-p'' option, won't you?" is naive. The option just preserves file's mtime, atime, flags, permissions, ACL, UID and GID as 
[[https://www.freebsd.org/cgi/man.cgi?cp|manpage]] says.

For instance, there is a file ''hasxattr.txt'' which has two extended attribute (OpusMetaInformation and DOSATTRIB.)

<code>
$ ls -al
total 42
drwxr-xr-x   2 Decomo  Decomo    3 10月 22 00:11 .
drwxr-xr-x  56 Decomo  Decomo  190 10月 21 23:43 ..
-rwxr--r--   1 Decomo  Decomo    0 10月 21 23:49 hasxattr.txt
$ lsextattr user *
hasxattr.txt    OpusMetaInformation     DOSATTRIB
</code>

Then, copy the file with ''cp -p''.

<code>
$ cp -p hasxattr.txt hasxattr_cp-p.txt
</code>

...and check extended attributes.
<code>
$ lsextattr user *
hasxattr.txt    OpusMetaInformation     DOSATTRIB
hasxattr_cp-p.txt
</code>

＼(^o^)／ < They've gone.

The destination file's extended attributes surely have been lost when I checked them as a color label with DirectoryOpus filer. (''OpusMetaInformation'' stored the label information.)

{{:blog:2019:freebsd_cp_losts_xattr.png|}}

As a one of EA lover, it's a pity.

I tried GNU cp provided by ''sysutils/coreutils'' ports, but his reply was loveless...

<code>
$ gcp --preserve=xattr hasxattr.txt hasxattr_gcp.txt
gcp: 拡張属性を保護できません。cp が xattr サポートなしで作成されています
</code>

It seems that ''rsync -X'' and ''mv'' preserve extended file attributes.

<code>
$ rsync -X hasxattr.txt hasxattr_rsync.txt
$ mv hasxattr.txt hasxattr_mv.txt
$ lsextattr user *
hasxattr_cp-p.txt
hasxattr_mv.txt OpusMetaInformation     DOSATTRIB
hasxattr_rsync.txt      OpusMetaInformation     DOSATTRIB
</code>

I found a wonderful page which described a support status of extended attributes of each command on FreeBSD, Linux and MacOS: [[https://www.lesbonscomptes.com/pages/extattrs.html|Extended attributes: the good, the not so good, the bad.]]

At any rate, I wish the coreutils ports could choice a option whether handling extended attributes or not.