BOOK/chapter06/systemd.xml

   1 <?xml version="1.0" encoding="ISO-8859-1"?>
   2 <!DOCTYPE sect1 PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
   3   "http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd" [
   4   <!ENTITY % general-entities SYSTEM "../general.ent">
   5   %general-entities;
   6 ]>
   7
   8 <sect1 id="ch-system-systemd" role="wrap" revision="systemd">
   9   <?dbhtml filename="systemd.html"?>
  10
  11   <sect1info condition="script">
  12     <productname>systemd</productname>
  13     <productnumber>&systemd-version;</productnumber>
  14     <address>&systemd-url;</address>
  15   </sect1info>
  16
  17   <title>Systemd-&systemd-version;</title>
  18
  19   <indexterm zone="ch-system-systemd">
  20     <primary sortas="a-systemd">systemd</primary>
  21   </indexterm>
  22
  23   <sect2 role="package">
  24     <title/>
  25
  26     <para>The systemd package contains programs for controlling the startup,
  27     running, and shutdown of the system.</para>
  28
  29     <segmentedlist>
  30       <segtitle>&buildtime;</segtitle>
  31       <segtitle>&diskspace;</segtitle>
  32
  33       <seglistitem>
  34         <seg>&systemd-ch6-sbu;</seg>
  35         <seg>&systemd-ch6-du;</seg>
  36       </seglistitem>
  37     </segmentedlist>
  38   </sect2>
  39
  40   <sect2 role="installation">
  41     <title>Installation of systemd</title>
  42
  43     <para>First, fix a build error when using Util-Linux built in
  44     Chapter 5:</para>
  45
  46 <screen><userinput remap="pre">sed -i "s:blkid/::" $(grep -rl "blkid/blkid.h")</userinput></screen>
  47
  48 <!-- Not needed as of 231. -renodr
  49     <para>Fix a potential security issue with framebuffer devices:</para>
  50
  51 <screen><userinput remap="pre">sed -e 's@DRI and frame buffer@DRI@'                  \
  52     -e '/SUBSYSTEM==\"graphics\", KERNEL==\"fb\*\"/d' \
  53     -i  src/login/70-uaccess.rules</userinput></screen>
  54 -->
  55
  56     <para>Disable two tests that always fail:</para>
  57
  58 <screen><userinput remap="pre">sed -e 's@test/udev-test.pl @@'  \
  59     -e 's@test-copy$(EXEEXT) @@' \
  60     -i Makefile.in</userinput></screen>
  61
  62 <!-- Not needed as of 232... anyone notice a pattern here? -renodr
  63     <para>Apply a patch to fix a security issue:</para>
  64
  65 <screen><userinput remap="pre">patch -Np1 -i ../systemd-231-security_fix-1.patch</userinput></screen>
  66 -->
  67
  68     <para>Create a file to allow systemd to build when using Util-Linux
  69     built in Chapter 5, to disable LTO by default, and to build without
  70     xlstproc:</para>
  71
  72 <screen><userinput remap="pre">cat &gt; config.cache &lt;&lt; "EOF"
  73 <literal>KILL=/bin/kill
  74 MOUNT_PATH=/bin/mount
  75 UMOUNT_PATH=/bin/umount
  76 HAVE_BLKID=1
  77 BLKID_LIBS="-lblkid"
  78 BLKID_CFLAGS="-I/tools/include/blkid"
  79 HAVE_LIBMOUNT=1
  80 MOUNT_LIBS="-lmount"
  81 MOUNT_CFLAGS="-I/tools/include/libmount"
  82 cc_cv_CFLAGS__flto=no
  83 SULOGIN="/sbin/sulogin"
  84 GPERF_LEN_TYPE=size_t
  85 XSLTPROC="/usr/bin/xsltproc"</literal>
  86 EOF</userinput></screen>
  87
  88     <para>LTO is disabled by default because it causes
  89     <command>systemd</command> and other auxiliary programs to link to
  90     <filename class="libraryfile">libgcc_s.so</filename>, slows the build down
  91     and makes the compiled code larger.</para>
  92
  93     <para>Prepare systemd for compilation:</para>
  94
  95 <screen><userinput remap="configure">./configure --prefix=/usr            \
  96             --sysconfdir=/etc        \
  97             --localstatedir=/var     \
  98             --config-cache           \
  99             --with-rootprefix=       \
 100             --with-rootlibdir=/lib   \
 101             --enable-split-usr       \
 102             --disable-firstboot      \
 103             --disable-ldconfig       \
 104             --disable-sysusers       \
 105             --without-python         \
 106             --with-default-dnssec=no \
 107             --docdir=/usr/share/doc/systemd-&systemd-version;</userinput></screen>
 108
 109     <variablelist>
 110       <title>The meaning of the configure options:</title>
 111
 112       <varlistentry>
 113         <term><parameter>--config-cache</parameter></term>
 114         <listitem>
 115           <para>This switch tells the build system to use
 116           the <filename>config.cache</filename> file which
 117           was created earlier.</para>
 118         </listitem>
 119       </varlistentry>
 120
 121       <varlistentry>
 122         <term><parameter>--with-root*</parameter></term>
 123         <listitem>
 124           <para>These switches ensure that core programs and
 125           shared libraries are installed in the subdirectories
 126           of the root partition.</para>
 127         </listitem>
 128       </varlistentry>
 129
 130       <varlistentry>
 131         <term><parameter>--enable-split-usr</parameter></term>
 132         <listitem>
 133           <para>This switch ensures that systemd will work on
 134           systems where /bin, /lib and /sbin directories are not
 135           symlinks to their /usr counterparts.</para>
 136         </listitem>
 137       </varlistentry>
 138
 139       <varlistentry>
 140         <term><parameter>--without-python</parameter></term>
 141         <listitem>
 142           <para>This switch prevents <command>configure</command>
 143           from trying to use Python which isn't built
 144           in LFS.</para>
 145         </listitem>
 146       </varlistentry>
 147
 148       <varlistentry>
 149         <term><parameter>--disable-firstboot</parameter></term>
 150         <listitem>
 151           <para>This switch prevents installation of systemd
 152           services responsible for setting up the system for
 153           the first time. They are not useful for LFS because
 154           everything is done manually.</para>
 155         </listitem>
 156       </varlistentry>
 157
 158       <varlistentry>
 159         <term><parameter>--disable-ldconfig</parameter></term>
 160         <listitem>
 161           <para>This switch prevents installation of a systemd
 162           unit that runs <command>ldconfig</command> at
 163           boot, making the boot time longer. Remove it if the
 164           described feature is desired, even though it's not
 165           useful for source distributions such as LFS.</para>
 166         </listitem>
 167       </varlistentry>
 168
 169       <varlistentry>
 170         <term><parameter>--disable-sysusers</parameter></term>
 171         <listitem>
 172           <para>This switch prevents installation of systemd
 173           services responsible for setting up the
 174           <filename>/etc/group</filename> and
 175           <filename>/etc/passwd</filename> files. Both files
 176           were created early in this chapter.</para>
 177         </listitem>
 178       </varlistentry>
 179
 180       <varlistentry>
 181         <term><parameter>--with-default-dnssec=no</parameter></term>
 182         <listitem>
 183           <para>This switch turns off the experimental DNSSEC suport.</para>
 184         </listitem>
 185       </varlistentry>
 186
 187     </variablelist>
 188
 189     <para>Fix a generated file:</para>
 190
 191 <screen><userinput remap="pre">sed -i s/size_t/GPERF_LEN_TYPE/ src/resolve/dns_type-from-name.h</userinput></screen>
 192
 193     <para>Compile the package:</para>
 194
 195 <screen><userinput remap="make">make LD_LIBRARY_PATH=/tools/lib</userinput></screen>
 196
 197     <para>This package has a test suite, but it can only be run after the
 198     package has been installed.</para>
 199
 200     <para>Install the package:</para>
 201
 202 <screen><userinput remap="install">make LD_LIBRARY_PATH=/tools/lib install</userinput></screen>
 203
 204 <!-- These get installed into /lib now by default.
 205     <para>Move the NSS libraries to <filename class="directory">/lib</filename>:</para>
 206
 207 <screen><userinput remap="install">mv -v /usr/lib/libnss_{myhostname,mymachines,resolve}.so.2 /lib</userinput></screen>
 208 -->
 209
 210     <para>Remove an unnecessary directory:</para>
 211
 212 <screen><userinput remap="install">rm -rfv /usr/lib/rpm</userinput></screen>
 213
 214     <para>Create the Sysvinit compatibility symlinks, so systemd is used
 215     as the default init system:</para>
 216
 217 <screen><userinput remap="install">for tool in runlevel reboot shutdown poweroff halt telinit; do
 218      ln -sfv ../bin/systemctl /sbin/${tool}
 219 done
 220 ln -sfv ../lib/systemd/systemd /sbin/init</userinput></screen>
 221
 222 <!--
 223     <para>Remove a reference to a non-existent group:</para>
 224
 225 <screen><userinput remap="install">sed -i "s:0775 root lock:0755 root root:g" /usr/lib/tmpfiles.d/legacy.conf</userinput></screen>
 226 -->
 227
 228     <para>Create the <filename>/etc/machine-id</filename> file needed by
 229     <command>systemd-journald</command>:</para>
 230
 231 <screen><userinput remap="install">systemd-machine-id-setup</userinput></screen>
 232
 233     <para>Since the testsuite largely depends on the host system kernel
 234     configuration, some tests may fail. It also needs a modification in
 235     order not to look for a program that will be installed by Util-Linux
 236     package later in this chapter. To test the results, issue:</para>
 237
 238 <screen><userinput remap="test">sed -i "s:minix:ext4:g" src/test/test-path-util.c
 239 make LD_LIBRARY_PATH=/tools/lib -k check</userinput></screen>
 240
 241   </sect2>
 242
 243   <sect2 id="contents-systemd" role="content">
 244     <title>Contents of systemd</title>
 245
 246     <segmentedlist>
 247       <segtitle>Installed programs</segtitle>
 248       <segtitle>Installed libraries</segtitle>
 249       <segtitle>Installed directories</segtitle>
 250
 251       <seglistitem>
 252         <seg>bootctl, busctl, coredumpctl, halt, hostnamectl, init, journalctl,
 253         kernel-install, localectl, loginctl, machinectl, networkctl, poweroff,
 254         reboot, runlevel, shutdown, systemctl, systemd-analyze,
 255         systemd-ask-password, systemd-cat, systemd-cgls, systemd-cgtop,
 256         systemd-delta, systemd-detect-virt, systemd-escape, systemd-hwdb,
 257         systemd-inhibit, systemd-machine-id-setup, systemd-mount,
 258         systemd-notify, systemd-nspawn, systemd-path, systemd-resolve,
 259         systemd-run, systemd-socket-activate,
 260         systemd-stdio-bridge, systemd-tmpfiles, systemd-tty-ask-password-agent,
 261         telinit, timedatectl, and udevadm</seg>
 262         <seg>libnss_myhostname.so.2, libnss_mymachines.so.2,
 263         libnss_resolve.so.2, libnss_systemd.so.2,
 264         libsystemd.so, libsystemd-shared-231.so,
 265         and libudev.so</seg>
 266         <seg>/etc/binfmt.d, /etc/init.d, /etc/kernel, /etc/modules-load.d,
 267         /etc/sysctl.d, /etc/systemd, /etc/tmpfiles.d, /etc/udev,
 268         /etc/xdg/systemd, /lib/systemd, /lib/udev, /usr/include/systemd,
 269         /usr/lib/binfmt.d, /usr/lib/kernel, /usr/lib/modules-load.d,
 270         /usr/lib/sysctl.d, /usr/lib/systemd, /usr/lib/tmpfiles.d,
 271         /usr/share/doc/systemd-&systemd-version;, /usr/share/factory,
 272         /usr/share/systemd, /var/lib/systemd, and /var/log/journal</seg>
 273       </seglistitem>
 274     </segmentedlist>
 275
 276     <variablelist>
 277       <bridgehead renderas="sect3">Short Descriptions</bridgehead>
 278       <?dbfo list-presentation="list"?>
 279       <?dbhtml list-presentation="table"?>
 280
 281       <varlistentry id="bootctl">
 282         <term><command>bootctl</command></term>
 283         <listitem>
 284           <para>used to query the firmware and boot manager settings</para>
 285           <indexterm zone="ch-system-systemd bootctl">
 286             <primary sortas="b-bootctl">bootctl</primary>
 287           </indexterm>
 288         </listitem>
 289       </varlistentry>
 290
 291       <varlistentry id="busctl">
 292         <term><command>busctl</command></term>
 293         <listitem>
 294           <para>Used to introspect and monitor the D-Bus bus</para>
 295           <indexterm zone="ch-system-systemd busctl">
 296             <primary sortas="b-busctl">busctl</primary>
 297           </indexterm>
 298         </listitem>
 299       </varlistentry>
 300
 301       <varlistentry id="coredumpctl">
 302         <term><command>coredumpctl</command></term>
 303         <listitem>
 304           <para>Used to retrieve coredumps from the systemd Journal</para>
 305           <indexterm zone="ch-system-systemd coredumpctl">
 306             <primary sortas="b-coredumpctl">coredumpctl</primary>
 307           </indexterm>
 308         </listitem>
 309       </varlistentry>
 310
 311       <varlistentry id="halt">
 312         <term><command>halt</command></term>
 313         <listitem>
 314           <para>Normally invokes <command>shutdown</command> with the
 315           <parameter>-h</parameter> option, except when already in run-level 0,
 316           then it tells the kernel to halt the system; it notes in the
 317           file <filename>/var/log/wtmp</filename> that the system is being
 318           brought down</para>
 319           <indexterm zone="ch-system-systemd halt">
 320             <primary sortas="b-halt">halt</primary>
 321           </indexterm>
 322         </listitem>
 323       </varlistentry>
 324
 325       <varlistentry id="hostnamectl">
 326         <term><command>hostnamectl</command></term>
 327         <listitem>
 328           <para>Used to query and change the system hostname and related
 329           settings</para>
 330           <indexterm zone="ch-system-systemd hostnamectl">
 331             <primary sortas="b-hostnamectl">hostnamectl</primary>
 332           </indexterm>
 333         </listitem>
 334       </varlistentry>
 335
 336       <varlistentry id="init">
 337         <term><command>init</command></term>
 338         <listitem>
 339           <para>The first process to be started when the kernel has initialized
 340           the hardware which takes over the boot process and starts all the
 341           proceses it is instructed to</para>
 342           <indexterm zone="ch-system-systemd init">
 343             <primary sortas="b-init">init</primary>
 344           </indexterm>
 345         </listitem>
 346       </varlistentry>
 347
 348       <varlistentry id="journalctl">
 349         <term><command>journalctl</command></term>
 350         <listitem>
 351           <para>Used to query the contents of the systemd Journal</para>
 352           <indexterm zone="ch-system-systemd journalctl">
 353             <primary sortas="b-journalctl">journalctl</primary>
 354           </indexterm>
 355         </listitem>
 356       </varlistentry>
 357
 358       <varlistentry id="kernel-install">
 359         <term><command>kernel-install</command></term>
 360         <listitem>
 361           <para>Used to add and remove kernel and initramfs images to and
 362           from /boot</para>
 363           <indexterm zone="ch-system-systemd kernel-install">
 364             <primary sortas="b-kernel-install">kernel-install</primary>
 365           </indexterm>
 366         </listitem>
 367       </varlistentry>
 368
 369       <varlistentry id="localectl">
 370         <term><command>localectl</command></term>
 371         <listitem>
 372           <para>Used to query and change the system locale and keyboard layout
 373           settings</para>
 374           <indexterm zone="ch-system-systemd localectl">
 375             <primary sortas="b-localectl">localectl</primary>
 376           </indexterm>
 377         </listitem>
 378       </varlistentry>
 379
 380       <varlistentry id="loginctl">
 381         <term><command>loginctl</command></term>
 382         <listitem>
 383           <para>Used to introspect and control the state of the systemd Login
 384           Manager</para>
 385           <indexterm zone="ch-system-systemd loginctl">
 386             <primary sortas="b-loginctl">loginctl</primary>
 387           </indexterm>
 388         </listitem>
 389       </varlistentry>
 390
 391       <varlistentry id="machinectl">
 392         <term><command>machinectl</command></term>
 393         <listitem>
 394           <para>Used to introspect and control the state of the systemd Virtual
 395           Machine and Container Registration Manager</para>
 396           <indexterm zone="ch-system-systemd machinectl">
 397             <primary sortas="b-machinectl">machinectl</primary>
 398           </indexterm>
 399         </listitem>
 400       </varlistentry>
 401
 402       <varlistentry id="networkctl">
 403         <term><command>networkctl</command></term>
 404         <listitem>
 405           <para>Used to introspect the state of the network links as seen by
 406           systemd-networkd</para>
 407           <indexterm zone="ch-system-systemd networkctl">
 408             <primary sortas="b-networkctl">networkctl</primary>
 409           </indexterm>
 410         </listitem>
 411       </varlistentry>
 412
 413       <varlistentry id="poweroff">
 414         <term><command>poweroff</command></term>
 415         <listitem>
 416           <para>Tells the kernel to halt the system and switch off the computer
 417           (see <command>halt</command>)</para>
 418           <indexterm zone="ch-system-systemd poweroff">
 419             <primary sortas="b-poweroff">poweroff</primary>
 420           </indexterm>
 421         </listitem>
 422       </varlistentry>
 423
 424       <varlistentry id="reboot">
 425         <term><command>reboot</command></term>
 426         <listitem>
 427           <para>Tells the kernel to reboot the system (see
 428           <command>halt</command>)</para>
 429           <indexterm zone="ch-system-systemd reboot">
 430             <primary sortas="b-reboot">reboot</primary>
 431           </indexterm>
 432         </listitem>
 433       </varlistentry>
 434
 435       <varlistentry id="runlevel">
 436         <term><command>runlevel</command></term>
 437         <listitem>
 438           <para>Reports the previous and the current run-level, as noted in the
 439           last run-level record in <filename>/var/run/utmp</filename></para>
 440           <indexterm zone="ch-system-systemd runlevel">
 441             <primary sortas="b-runlevel">runlevel</primary>
 442           </indexterm>
 443         </listitem>
 444       </varlistentry>
 445
 446       <varlistentry id="shutdown">
 447         <term><command>shutdown</command></term>
 448         <listitem>
 449           <para>Brings the system down in a secure way, signaling all processes
 450           and notifying all logged-in users</para>
 451           <indexterm zone="ch-system-systemd shutdown">
 452             <primary sortas="b-shutdown">shutdown</primary>
 453           </indexterm>
 454         </listitem>
 455       </varlistentry>
 456
 457       <varlistentry id="systemctl">
 458         <term><command>systemctl</command></term>
 459         <listitem>
 460           <para>Used to introspect and control the state of the systemd system
 461           and service manager</para>
 462           <indexterm zone="ch-system-systemd systemctl">
 463             <primary sortas="b-systemctl">systemctl</primary>
 464           </indexterm>
 465         </listitem>
 466       </varlistentry>
 467
 468       <varlistentry id="systemd-analyze">
 469         <term><command>systemd-analyze</command></term>
 470         <listitem>
 471           <para>Used to determine system boot-up performance of the current
 472           boot</para>
 473           <indexterm zone="ch-system-systemd systemd-analyze">
 474             <primary sortas="b-systemd-analyze">systemd-analyze</primary>
 475           </indexterm>
 476         </listitem>
 477       </varlistentry>
 478
 479       <varlistentry id="systemd-ask-password">
 480         <term><command>systemd-ask-password</command></term>
 481         <listitem>
 482           <para>Used to query a system password or passphrase from the user,
 483           using a question message specified on the command line</para>
 484           <indexterm zone="ch-system-systemd systemd-ask-password">
 485             <primary sortas="b-systemd-ask-password">systemd-ask-password</primary>
 486           </indexterm>
 487         </listitem>
 488       </varlistentry>
 489
 490       <varlistentry id="systemd-cat">
 491         <term><command>systemd-cat</command></term>
 492         <listitem>
 493           <para>Used to connect STDOUT and STDERR of a process with the Journal
 494           </para>
 495           <indexterm zone="ch-system-systemd systemd-cat">
 496             <primary sortas="b-systemd-cat">systemd-cat</primary>
 497           </indexterm>
 498         </listitem>
 499       </varlistentry>
 500
 501       <varlistentry id="systemd-cgls">
 502         <term><command>systemd-cgls</command></term>
 503         <listitem>
 504           <para>Recursively shows the contents of the selected Linux control
 505           group hierarchy in a tree</para>
 506           <indexterm zone="ch-system-systemd systemd-cgls">
 507             <primary sortas="b-systemd-cgls">systemd-cgls</primary>
 508           </indexterm>
 509         </listitem>
 510       </varlistentry>
 511
 512       <varlistentry id="systemd-cgtop">
 513         <term><command>systemd-cgtop</command></term>
 514         <listitem>
 515           <para>Shows the top control groups of the local Linux control group
 516           hierarchy, ordered by their CPU, memory and disk I/O load</para>
 517           <indexterm zone="ch-system-systemd systemd-cgtop">
 518             <primary sortas="b-systemd-cgtop">systemd-cgtop</primary>
 519           </indexterm>
 520         </listitem>
 521       </varlistentry>
 522
 523       <varlistentry id="systemd-delta">
 524         <term><command>systemd-delta</command></term>
 525         <listitem>
 526           <para>Used to identify and compare configuration files in
 527           <filename class="directory">/etc</filename> that override default
 528           counterparts in <filename class="directory">/usr</filename></para>
 529           <indexterm zone="ch-system-systemd systemd-delta">
 530             <primary sortas="b-systemd-delta">systemd-delta</primary>
 531           </indexterm>
 532         </listitem>
 533       </varlistentry>
 534
 535       <varlistentry id="systemd-detect-virt">
 536         <term><command>systemd-detect-virt</command></term>
 537         <listitem>
 538           <para>Detects execution in a virtualized environment</para>
 539           <indexterm zone="ch-system-systemd systemd-detect-virt">
 540             <primary sortas="b-systemd-detect-virt">systemd-detect-virt</primary>
 541           </indexterm>
 542         </listitem>
 543       </varlistentry>
 544
 545       <varlistentry id="systemd-escape">
 546         <term><command>systemd-escape</command></term>
 547         <listitem>
 548           <para>Used to escape strings for inclusion in systemd unit
 549           names</para>
 550           <indexterm zone="ch-system-systemd systemd-escape">
 551             <primary sortas="b-systemd-escape">systemd-escape</primary>
 552           </indexterm>
 553         </listitem>
 554       </varlistentry>
 555
 556       <varlistentry id="systemd-hwdb">
 557         <term><command>systemd-hwdb</command></term>
 558         <listitem>
 559           <para>Used to manage hardware database (hwdb)</para>
 560           <indexterm zone="ch-system-systemd systemd-hwdb">
 561             <primary sortas="b-systemd-hwdb">systemd-hwdb</primary>
 562           </indexterm>
 563         </listitem>
 564       </varlistentry>
 565
 566       <varlistentry id="systemd-inhibit">
 567         <term><command>systemd-inhibit</command></term>
 568         <listitem>
 569           <para>Used to execute a program with a shutdown, sleep or idle
 570           inhibitor lock taken</para>
 571           <indexterm zone="ch-system-systemd systemd-inhibit">
 572             <primary sortas="b-systemd-inhibit">systemd-inhibit</primary>
 573           </indexterm>
 574         </listitem>
 575       </varlistentry>
 576
 577       <varlistentry id="systemd-machine-id-setup">
 578         <term><command>systemd-machine-id-setup</command></term>
 579         <listitem>
 580           <para>Used by system installer tools to initialize the machine ID
 581           stored in <filename>/etc/machine-id</filename> at install time with a
 582           randomly generated ID</para>
 583           <indexterm zone="ch-system-systemd systemd-machine-id-setup">
 584             <primary sortas="b-systemd-machine-id-setup">systemd-machine-id-setup</primary>
 585           </indexterm>
 586         </listitem>
 587       </varlistentry>
 588
 589       <varlistentry id="systemd-mount">
 590         <term><command>systemd-mount</command></term>
 591         <listitem>
 592           <para>is a tool to temporarily mount or auto-mount a drive.</para>
 593           <indexterm zone="ch-system-systemd systemd-mount">
 594             <primary sortas="b-systemd-mount">systemd-mount</primary>
 595           </indexterm>
 596         </listitem>
 597       </varlistentry>
 598
 599       <varlistentry id="systemd-notify">
 600         <term><command>systemd-notify</command></term>
 601         <listitem>
 602           <para>Used by daemon scripts to notify the init system about status
 603           changes</para>
 604           <indexterm zone="ch-system-systemd systemd-notify">
 605             <primary sortas="b-systemd-notify">systemd-notify</primary>
 606           </indexterm>
 607         </listitem>
 608       </varlistentry>
 609
 610       <varlistentry id="systemd-nspawn">
 611         <term><command>systemd-nspawn</command></term>
 612         <listitem>
 613           <para>Used to run a command or OS in a light-weight namespace
 614           container</para>
 615           <indexterm zone="ch-system-systemd systemd-nspawn">
 616             <primary sortas="b-systemd-nspawn">systemd-nspawn</primary>
 617           </indexterm>
 618         </listitem>
 619       </varlistentry>
 620
 621       <varlistentry id="systemd-path">
 622         <term><command>systemd-path</command></term>
 623         <listitem>
 624           <para>Used to query system and user paths</para>
 625           <indexterm zone="ch-system-systemd systemd-path">
 626             <primary sortas="b-systemd-path">systemd-path</primary>
 627           </indexterm>
 628         </listitem>
 629       </varlistentry>
 630
 631       <varlistentry id="systemd-resolve">
 632         <term><command>systemd-resolve</command></term>
 633         <listitem>
 634           <para>Used to resolve domain names, IPV4 and IPv6 addresses, DNS
 635           resource records, and services</para>
 636           <indexterm zone="ch-system-systemd systemd-resolve">
 637             <primary sortas="b-systemd-resolve">systemd-resolve</primary>
 638           </indexterm>
 639         </listitem>
 640       </varlistentry>
 641
 642       <varlistentry id="systemd-run">
 643         <term><command>systemd-run</command></term>
 644         <listitem>
 645           <para>Used to create and start a transient .service or a .scope unit
 646           and run the specified command in it</para>
 647           <indexterm zone="ch-system-systemd systemd-run">
 648             <primary sortas="b-systemd-run">systemd-run</primary>
 649           </indexterm>
 650         </listitem>
 651       </varlistentry>
 652
 653       <!-- <varlistentry id="systemd-stdio-bridge">
 654         <term><command>systemd-stdio-bridge</command></term>
 655         <listitem>
 656           <para>To be completed</para>
 657           <indexterm zone="ch-system-systemd systemd-stdio-bridge">
 658             <primary sortas="b-systemd-stdio-bridge">systemd-stdio-bridge</primary>
 659           </indexterm>
 660         </listitem>
 661       </varlistentry> -->
 662
 663       <varlistentry id="systemd-socket-activate">
 664         <term><command>systemd-socket-activate</command></term>
 665         <listitem>
 666           <para>is a tool to listen on socket devices and launch a process upon
 667           connection.</para>
 668           <indexterm zone="ch-system-systemd systemd-socket-activate">
 669             <primary sortas="b-systemd-socket-activate">systemd-socket-activate</primary>
 670           </indexterm>
 671         </listitem>
 672       </varlistentry>
 673
 674       <varlistentry id="systemd-tmpfiles">
 675         <term><command>systemd-tmpfiles</command></term>
 676         <listitem>
 677           <para>Creates, deletes and cleans up volatile and temporary files and
 678           directories, based on the configuration file format and location
 679           specified in
 680           <filename class="directory">tmpfiles.d</filename> directories</para>
 681           <indexterm zone="ch-system-systemd systemd-tmpfiles">
 682             <primary sortas="b-systemd-tmpfiles">systemd-tmpfiles</primary>
 683           </indexterm>
 684         </listitem>
 685       </varlistentry>
 686
 687       <varlistentry id="systemd-tty-ask-password-agent">
 688         <term><command>systemd-tty-ask-password-agent</command></term>
 689         <listitem>
 690           <para>Used to list or process pending systemd password requests</para>
 691           <indexterm zone="ch-system-systemd systemd-tty-ask-password-agent">
 692             <primary sortas="b-systemd-tty-ask-password-agent">systemd-tty-ask-password-agent</primary>
 693           </indexterm>
 694         </listitem>
 695       </varlistentry>
 696
 697       <varlistentry id="telinit">
 698         <term><command>telinit</command></term>
 699         <listitem>
 700           <para>Tells <command>init</command> which run-level to change
 701           to</para>
 702           <indexterm zone="ch-system-systemd telinit">
 703             <primary sortas="b-telinit">telinit</primary>
 704           </indexterm>
 705         </listitem>
 706       </varlistentry>
 707
 708       <varlistentry id="timedatectl">
 709         <term><command>timedatectl</command></term>
 710         <listitem>
 711           <para>Used to query and change the system clock and its settings
 712           </para>
 713           <indexterm zone="ch-system-systemd timedatectl">
 714             <primary sortas="b-timedatectl">timedatectl</primary>
 715           </indexterm>
 716         </listitem>
 717       </varlistentry>
 718
 719       <varlistentry id="udevadm">
 720         <term><command>udevadm</command></term>
 721         <listitem>
 722           <para>Generic Udev administration tool: controls the udevd daemon,
 723           provides info from the Udev database, monitors uevents, waits for
 724           uevents to finish, tests Udev configuration, and triggers uevents
 725           for a given device</para>
 726           <indexterm zone="ch-system-systemd udevadm">
 727             <primary sortas="b-udevadm">udevadm</primary>
 728           </indexterm>
 729         </listitem>
 730       </varlistentry>
 731
 732       <varlistentry id="libsystemd">
 733         <term><filename class="libraryfile">libsystemd</filename></term>
 734         <listitem>
 735           <para>systemd utility library</para>
 736           <indexterm zone="ch-system-systemd libsystemd">
 737             <primary sortas="c-libsystemd">libsystemd</primary>
 738           </indexterm>
 739         </listitem>
 740       </varlistentry>
 741
 742       <varlistentry id="libudev">
 743         <term><filename class="libraryfile">libudev</filename></term>
 744         <listitem>
 745           <para>A library to access Udev device information</para>
 746           <indexterm zone="ch-system-systemd libudev">
 747             <primary sortas="c-libudev">libudev</primary>
 748           </indexterm>
 749         </listitem>
 750       </varlistentry>
 751
 752     </variablelist>
 753
 754   </sect2>
 755
 756 </sect1>