core: use id unit when retrieving unit file state (#8038)

[thirdparty/systemd.git] / UIDS-GIDS.md

diff --git a/UIDS-GIDS.md b/UIDS-GIDS.md
index d44d93d144837949cc81a3f4dd32f36878e603a2..e19cc88162378b40c935639daa69c9f64923b8cc 100644 (file)
--- a/UIDS-GIDS.md
+++ b/UIDS-GIDS.md
@@ -17,22 +17,23 @@ i.e. 0…4294967295. However, four UIDs are special on Linux:
 1. 0 → The `root` super-user
 
 2. 65534 → The `nobody` UID, also called the "overflow" UID or similar. It's
-   where various subsystems map unmappable users to, for example NFS or user
-   namespacing. (The latter can be changed with a sysctl during runtime, but
-   that's not supported on `systemd`. If you do change it you void your
-   warranty.) Because Fedora is a bit confused the `nobody` user is called
-   `nfsnobody` there (and they have a different `nobody` user at UID 99). I
-   hope this will be corrected eventually though. (Also, some distributions
-   call the `nobody` group `nogroup`. I wish they didn't.)
+   where various subsystems map unmappable users to, for example file systems
+   only supporting 16bit UIDs, NFS or user namespacing. (The latter can be
+   changed with a sysctl during runtime, but that's not supported on
+   `systemd`. If you do change it you void your warranty.) Because Fedora is a
+   bit confused the `nobody` user is called `nfsnobody` there (and they have a
+   different `nobody` user at UID 99). I hope this will be corrected eventually
+   though. (Also, some distributions call the `nobody` group `nogroup`. I wish
+   they didn't.)
 
 3. 4294967295, aka "32bit `(uid_t) -1`" → This UID is not a valid user ID, as
-   setresuid(), chown() and friends treat -1 as a special request to not change
-   the UID of the process/file. This UID is hence not available for assignment
-   to users in the user database.
+   `setresuid()`, `chown()` and friends treat -1 as a special request to not
+   change the UID of the process/file. This UID is hence not available for
+   assignment to users in the user database.
 
-4. 65535, aka "16bit `(uid_t) -1`" → Once upon a time `uid_t` used to be 16bit, and
-   programs compiled for that would hence assume that `(uid_t) -1` is 65535. This
-   UID is hence not usable either.
+4. 65535, aka "16bit `(uid_t) -1`" → Before Linux kernel 2.4 `uid_t` used to be
+   16bit, and programs compiled for that would hence assume that `(uid_t) -1`
+   is 65535. This UID is hence not usable either.
 
 The `nss-systemd` glibc NSS module will synthesize user database records for
 the UIDs 0 and 65534 if the system user database doesn't list them. This means