Hi,

On 24/3/23 21:42, Didier Kryn wrote:
> Good question. The user can't. It could be any of the programs
> involved in initializing a user session, like console-kit.

It's elogind's function:

static int user_mkdir_runtime_path(
    const char *runtime_path,
    uid_t uid,
    gid_t gid,
    uint64_t runtime_dir_size,
    uint64_t runtime_dir_inodes);

in "user-runtime-dir.c":

https://github.com/elogind/elogind/blob/main/src/login/user-runtime-dir.c

Cheers,

Aitor.