Changeset dd7a29e for chapter07/createfiles.xml

Timestamp:

05/02/2022 08:05:51 AM (2 years ago)

Author:

Xi Ruoyao <xry111@…>

Branches:

xry111/clfs-ng

Children:

100ca4e

Parents:

b1df1d7 (diff), 7c862ea (diff)
Note: this is a merge changeset, the changes displayed below correspond to the merge itself.
Use the (diff) links above to see all the changes relative to each parent.

Message:

Merge branch 'trunk' into xry111/clfs-ng

File:

• chapter07/createfiles.xml (modified) (5 diffs)

chapter07/createfiles.xml

@@ -67 +67 @@
 messagebus:x:18:18:D-Bus Message Daemon User:/run/dbus:/usr/bin/false
 uuidd:x:80:80:UUID Generation Daemon User:/dev/null:/usr/bin/false
-nobody:x:99:99:Unprivileged User:/dev/null:/usr/bin/false</literal>
+nobody:x:65534:65534:Unprivileged User:/dev/null:/usr/bin/false</literal>
 EOF</userinput></screen>
 
@@ -84 +84 @@
 uuidd:x:80:80:UUID Generation Daemon User:/dev/null:/usr/bin/false
 systemd-oom:x:81:81:systemd Out Of Memory Daemon:/:/usr/bin/false
-nobody:x:99:99:Unprivileged User:/dev/null:/usr/bin/false</literal>
+nobody:x:65534:65534:Unprivileged User:/dev/null:/usr/bin/false</literal>
 EOF</userinput></screen>
 
@@ -117 +117 @@
 uuidd:x:80:
 wheel:x:97:
-nogroup:x:99:
-users:x:999:</literal>
+users:x:999:
+nogroup:x:65534:</literal>
 EOF</userinput></screen>
 
@@ -154 +154 @@
 systemd-oom:x:81:
 wheel:x:97:
-nogroup:x:99:
-users:x:999:</literal>
+users:x:999:
+nogroup:x:65534:</literal>
 EOF</userinput></screen>
 
@@ -166 +166 @@
   besides the group <systemitem class="groupname">root</systemitem> with a
   Group ID (GID) of 0, a group <systemitem class="groupname">bin</systemitem>
-  with a GID of 1 be present. All other group names and GIDs can be chosen
-  freely by the system administrator since well-written programs do not depend
-  on GID numbers, but rather use the group's name.</para>
+  with a GID of 1 be present. The GID of 5 is widely used for
+  <systemitem class="groupname">tty</systemitem> group, and the number 5 is
+  also used in <phrase revision="systemd">systemd</phrase>
+  <phrase revision="sysv"><filename>/etc/fstab</filename></phrase> for the
+  <systemitem class="filesystem">devpts</systemitem> filesystem.
+  All other group names and GIDs can be chosen freely by the system
+  administrator since well-written programs do not depend on GID numbers,
+  but rather use the group's name.</para>
+
+  <para>The ID 65534 is used by the kernel for NFS and separate user
+  namespaces for unmapped users and groups (those exist on the NFS server
+  or the parent user namespace, but <quote>do not exist</quote> on the local
+  machine or in the separate namespace).  We assign
+  <systemitem class="username">nobody</systemitem> and
+  <systemitem class="groupname">nogroup</systemitem> for it to avoid an
+  unnamed ID.  But other distros may treat this ID differently, so any
+  portable program should not depend on this assignment.</para>
 
   <para>Some tests in <xref linkend="chapter-building-system"/> need a regular