HYPHEN is escaped in filename by "\x2d"

[Bernhard Riegler]

on Ubuntu22.04LTS I get the following filenames.
root@prod:/home/bernie22/fw# find / -xdev -name '*\x2d*'
/etc/systemd/system/snap-gtk\x2dcommon\x2dthemes-1535.mount
/etc/systemd/system/snap-gnome\x2d3\x2d38\x2d2004-115.mount
/etc/systemd/system/multi-user.target.wants/snap-gtk\x2dcommon\x2dthemes-1535.mount
/etc/systemd/system/multi-user.target.wants/snap-gnome\x2d3\x2d38\x2d2004-115.mount
/etc/systemd/system/multi-user.target.wants/snap-snapd\x2ddesktop\x2dintegration-14.mount
/etc/systemd/system/multi-user.target.wants/snap-snap\x2dstore-599.mount
/etc/systemd/system/multi-user.target.wants/snap-hunspell\x2ddictionaries\x2d1\x2d7\x2d2004-2.mount
/etc/systemd/system/snap-snapd\x2ddesktop\x2dintegration-14.mount
/etc/systemd/system/snap-snap\x2dstore-599.mount
/etc/systemd/system/snap-hunspell\x2ddictionaries\x2d1\x2d7\x2d2004-2.mount
/etc/systemd/system/default.target.wants/snap-gtk\x2dcommon\x2dthemes-1535.mount
/etc/systemd/system/default.target.wants/snap-gnome\x2d3\x2d38\x2d2004-115.mount
/etc/systemd/system/default.target.wants/snap-snapd\x2ddesktop\x2dintegration-14.mount
/etc/systemd/system/default.target.wants/snap-snap\x2dstore-599.mount
/etc/systemd/system/default.target.wants/snap-hunspell\x2ddictionaries\x2d1\x2d7\x2d2004-2.mount

why is the ASCII character HYPHEN escaped ?
remove this "\x2d"
a BACKSLASH is the source of a lot of troubles with filenames in UNIX and GNU/Linux.

[Alberto Mardegan (mardy)]

Hi Bernhard, the names of these files are not decided by snapd, but they follow systemd rules:
https://www.freedesktop.org/software/systemd/man/systemd.unit.html#String%20Escaping%20for%20Inclusion%20in%20Unit%20Names

I'll close this, but feel free to file a bug against upstream systemd (https://github.com/systemd/systemd/issues) if you think that this convention is wrong. I don't think they'd bother though, because it has been like this for many years, applications rely on this format, and moreover these are not files that the user should have the need to modify or move.

[Alberto Mardegan (mardy)]

OK, it turns out that after moving the bug to systemd, I don't have permissions to close it anymore :-)

[Bernhard Riegler (riegler-b)]

thanks Alberto,
for pointing me to the details of systemd rules.

I am a fan of KISS (keep it simple s.......) any exception is one too much.

I still consider this a filesystem namespace pollution.
I work with UNIX since 1980, before GNU/Linux.
systemd master mind is ignoring the history of UNIX.

Now I understand why so many linux distributions reject this process PID=1 concept.

SLASH and BACKSLASH is a NO-NO in filenames.