source: BOOK/final-system/common/util-linux.xml@ 9793117

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<!DOCTYPE sect1 PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
  "http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd" [
  <!ENTITY % general-entities SYSTEM "../../general.ent">
  %general-entities;
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<sect1 id="ch-system-util-linux" role="wrap">
  <?dbhtml filename="util-linux.html"?>

  <title>Util-linux-&util-linux-version;</title>

  <indexterm zone="ch-system-util-linux">
    <primary sortas="a-Util-linux">Util-linux</primary>
  </indexterm>

  <sect2 role="package">
    <title/>

    <para>The Util-linux package contains miscellaneous utility programs.
    Among them are utilities for handling file systems, consoles, partitions,
    and messages.</para>

  </sect2>

  <sect2 id="fhs-util-linux" role="installation">
    <title>FHS compliance notes</title>

    <para>The FHS recommends using the <filename
    class="directory">/var/lib/hwclock</filename> directory instead of the
    usual <filename class="directory">/etc</filename> directory as the
    location for the <filename>adjtime</filename> file. To make the
    <command>hwclock</command> program FHS-compliant, run the following:</para>

<screen><userinput>sed -i 's@etc/adjtime@var/lib/hwclock/adjtime@g' \
    hwclock/hwclock.c
mkdir -pv /var/lib/hwclock</userinput></screen>

  </sect2>

  <sect2 role="installation">
    <title>Installation of Util-linux</title>

    <para os="a">Prepare Util-linux for compilation:</para>

<screen os="b"><userinput>./configure --enable-arch \
    --enable-partx --enable-write --disable-wall</userinput></screen>

    <variablelist os="c">
      <title>The meaning of the configure options:</title>

      <varlistentry>
        <term><parameter>--enable-arch</parameter></term>
        <listitem>
          <para>This option allows the <command>arch</command> program to be
          installed.</para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><parameter>--enable-partx</parameter></term>
        <listitem>
          <para>Enables building the <command>addpart</command>, <command>delpart</command>,
           <command>partx</command> programs.</para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><parameter>--enable-write</parameter></term>
        <listitem>
          <para>This option allows the <command>write</command> program to be
          installed.</para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><parameter>--disable-wall</parameter></term>
        <listitem>
          <para>Disables building the <command>wall</command> program,
          as the Sysvinit package installs its own version.</para>
        </listitem>
      </varlistentry>

    </variablelist>

    <para os="d">Compile the package:</para>

<screen os="e"><userinput>make</userinput></screen>

    <para os="f">This package does not come with a test suite.</para>

    <para os="g">Install the package:</para>

<screen os="h"><userinput>make install</userinput></screen>

  </sect2>

  <sect2 id="contents-util-linux" role="content">
    <title>Contents of Util-linux</title>

    <segmentedlist>
      <segtitle>Installed programs</segtitle>
      <segtitle>Installed libraries</segtitle>
      <segtitle>Installed directories</segtitle>

      <seglistitem>
        <seg>addpart, agetty, arch, blkid, blockdev, cal, cfdisk, chkdupexe,
        chrt, col, colcrt, colrm, column, ctrlaltdel, cytune, ddate, delpart,
        dmesg, fdformat, fdisk, findfs, flock, fsck, fsck.cramfs, fsck.minix,
        getopt, hexdump, hwclock, ionice, ipcmk, ipcrm, ipcs, isosize,
        ldattach, line, logger, look, losetup, lscpu, mcookie, mkfs, mkfs.bfs,
        mkfs.cramfs, mkfs.minix, mkswap, more, mount, namei, partx, pg,
        pivot_root, readprofile, rename, renice, rev, rtcwake, script,
        scriptreplay, setarch, setsid, setterm, sfdisk, swapoff (link to
        swapon), swapon, switch_root, tailf, taskset, tunelp, ul, umount,
        uuidd, uuidgen, whereis, and write</seg>
        <seg>libblkid.[a,so] and libuuid.[a,so]</seg>
        <seg>/usr/include/blkid, /usr/include/uuid, /usr/share/getopt,
        /var/lib/hwclock</seg>
      </seglistitem>
    </segmentedlist>

    <variablelist>
      <bridgehead renderas="sect3">Short Descriptions</bridgehead>
      <?dbfo list-presentation="list"?>
      <?dbhtml list-presentation="table"?>

      <varlistentry id="addpart">
        <term><command>addpart</command></term>
        <listitem>
          <para>Informs the kernel of a new partition</para>
          <indexterm zone="ch-system-util-linux addpart">
            <primary sortas="b-addpart">addpart</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="agetty">
        <term><command>agetty</command></term>
        <listitem>
          <para>Opens a tty port, prompts for a login name,
          and then invokes the <command>login</command> program</para>
          <indexterm zone="ch-system-util-linux agetty">
            <primary sortas="b-agetty">agetty</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="arch">
        <term><command>arch</command></term>
        <listitem>
          <para>Reports the machine's architecture</para>
          <indexterm zone="ch-system-util-linux arch">
            <primary sortas="b-arch">arch</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="blkid">
        <term><command>blkid</command></term>
        <listitem>
          <para>A command line utility to locate and print block device
          attributes</para>
          <indexterm zone="ch-system-util-linux blkid">
            <primary sortas="b-blkid">blkid</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="blockdev">
        <term><command>blockdev</command></term>
        <listitem>
          <para>Allows users to call block device ioctls from the command
          line</para>
          <indexterm zone="ch-system-util-linux blockdev">
            <primary sortas="b-blockdev">blockdev</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="cal">
        <term><command>cal</command></term>
        <listitem>
          <para>Displays a simple calendar</para>
          <indexterm zone="ch-system-util-linux cal">
            <primary sortas="b-cal">cal</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="cfdisk">
        <term><command>cfdisk</command></term>
        <listitem>
          <para>Manipulates the partition table of the given device</para>
          <indexterm zone="ch-system-util-linux cfdisk">
            <primary sortas="b-cfdisk">cfdisk</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="chkdupexe">
        <term><command>chkdupexe</command></term>
        <listitem>
          <para>Finds duplicate executables</para>
          <indexterm zone="ch-system-util-linux chkdupexe">
            <primary sortas="b-chkdupexe">chkdupexe</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="chrt">
        <term><command>chrt</command></term>
        <listitem>
          <para>Manipulates real-time attributes of a process</para>
          <indexterm zone="ch-system-util-linux chrt">
            <primary sortas="b-chrt">chrt</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="col">
        <term><command>col</command></term>
        <listitem>
          <para>Filters out reverse line feeds</para>
          <indexterm zone="ch-system-util-linux col">
            <primary sortas="b-col">col</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="colcrt">
        <term><command>colcrt</command></term>
        <listitem>
          <para>Filters <command>nroff</command> output for terminals
          that lack some capabilities, such as overstriking and half-lines</para>
          <indexterm zone="ch-system-util-linux colcrt">
            <primary sortas="b-colcrt">colcrt</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="colrm">
        <term><command>colrm</command></term>
        <listitem>
          <para>Filters out the given columns</para>
          <indexterm zone="ch-system-util-linux colrm">
            <primary sortas="b-colrm">colrm</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="column">
        <term><command>column</command></term>
        <listitem>
          <para>Formats a given file into multiple columns</para>
          <indexterm zone="ch-system-util-linux column">
            <primary sortas="b-column">column</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="ctrlaltdel">
        <term><command>ctrlaltdel</command></term>
        <listitem>
          <para>Sets the function of the Ctrl+Alt+Del key combination to a
          hard or a soft reset</para>
          <indexterm zone="ch-system-util-linux ctrlaltdel">
            <primary sortas="b-ctrlaltdel">ctrlaltdel</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="cytune">
        <term><command>cytune</command></term>
        <listitem>
          <para>Tunes the parameters of the serial line drivers for
          Cyclades cards</para>
          <indexterm zone="ch-system-util-linux cytune">
            <primary sortas="b-cytune">cytune</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="ddate">
        <term><command>ddate</command></term>
        <listitem>
          <para>Gives the Discordian date or converts the given Gregorian date
          to a Discordian one</para>
          <indexterm zone="ch-system-util-linux ddate">
            <primary sortas="b-ddate">ddate</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="delpart">
        <term><command>delpart</command></term>
        <listitem>
          <para>Asks the kernel to remove a partition</para>
          <indexterm zone="ch-system-util-linux delpart">
            <primary sortas="b-delpart">delpart</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="dmesg">
        <term><command>dmesg</command></term>
        <listitem>
          <para>Dumps the kernel boot messages</para>
          <indexterm zone="ch-system-util-linux dmesg">
            <primary sortas="b-dmesg">dmesg</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="fdformat">
        <term><command>fdformat</command></term>
        <listitem>
          <para>Low-level formats a floppy disk</para>
          <indexterm zone="ch-system-util-linux fdformat">
            <primary sortas="b-fdformat">fdformat</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="fdisk">
        <term><command>fdisk</command></term>
        <listitem>
          <para>Manipulates the partition table of the given device</para>
          <indexterm zone="ch-system-util-linux fdisk">
            <primary sortas="b-fdisk">fdisk</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="findfs">
        <term><command>findfs</command></term>
        <listitem>
          <para>Finds a file system by label or Universally Unique Identifier
          (UUID)</para>
          <indexterm zone="ch-system-util-linux findfs">
            <primary sortas="b-findfs">findfs</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="flock">
        <term><command>flock</command></term>
        <listitem>
          <para>Acquires a file lock and then executes a command with the lock
          held</para>
          <indexterm zone="ch-system-util-linux flock">
            <primary sortas="b-flock">flock</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="fsck">
        <term><command>fsck</command></term>
        <listitem>
          <para>Is used to check, and optionally repair, file systems</para>
          <indexterm zone="ch-system-util-linux fsck">
            <primary sortas="b-fsck">fsck</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="fsck.cramfs">
        <term><command>fsck.cramfs</command></term>
        <listitem>
          <para>Performs a consistency check on the Cramfs file system on the
          given device</para>
          <indexterm zone="ch-system-util-linux fsck.cramfs">
            <primary sortas="b-fsck.cramfs">fsck.cramfs</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="fsck.minix">
        <term><command>fsck.minix</command></term>
        <listitem>
          <para>Performs a consistency check on the Minix file system on the
          given device</para>
          <indexterm zone="ch-system-util-linux fsck.minix">
            <primary sortas="b-fsck.minix">fsck.minix</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="getopt">
        <term><command>getopt</command></term>
        <listitem>
          <para>Parses options in the given command line</para>
          <indexterm zone="ch-system-util-linux getopt">
            <primary sortas="b-getopt">getopt</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="hexdump">
        <term><command>hexdump</command></term>
        <listitem>
          <para>Dumps the given file in hexadecimal or in another given
          format</para>
          <indexterm zone="ch-system-util-linux hexdump">
            <primary sortas="b-hexdump">hexdump</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="hwclock">
        <term><command>hwclock</command></term>
        <listitem>
          <para>Reads or sets the system's hardware clock, also called
          the Real-Time Clock (RTC) or Basic Input-Output System (BIOS)
          clock</para>
          <indexterm zone="ch-system-util-linux hwclock">
            <primary sortas="b-hwclock">hwclock</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="ionice">
        <term><command>ionice</command></term>
        <listitem>
          <para>Gives and sets program I/O scheduling class and priority</para>
          <indexterm zone="ch-system-util-linux ionice">
            <primary sortas="b-ionice">ionice</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="ipcmk">
        <term><command>ipcmk</command></term>
        <listitem>
          <para>Creates various IPC resources</para>
          <indexterm zone="ch-system-util-linux ipcmk">
            <primary sortas="b-ipcmk">ipcmk</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="ipcrm">
        <term><command>ipcrm</command></term>
        <listitem>
          <para>Removes the given Inter-Process Communication (IPC) resource</para>
          <indexterm zone="ch-system-util-linux ipcrm">
            <primary sortas="b-ipcrm">ipcrm</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="ipcs">
        <term><command>ipcs</command></term>
        <listitem>
          <para>Provides IPC status information</para>
          <indexterm zone="ch-system-util-linux ipcs">
            <primary sortas="b-ipcs">ipcs</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="isosize">
        <term><command>isosize</command></term>
        <listitem>
          <para>Reports the size of an iso9660 file system</para>
          <indexterm zone="ch-system-util-linux isosize">
            <primary sortas="b-isosize">isosize</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="ldattach">
        <term><command>ldattach</command></term>
        <listitem>
          <para>Attaches a line discipline to a serial line</para>
          <indexterm zone="ch-system-util-linux ldattach">
            <primary sortas="b-ldattach">ldattach</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="line">
        <term><command>line</command></term>
        <listitem>
          <para>Copies a single line</para>
          <indexterm zone="ch-system-util-linux line">
            <primary sortas="b-line">line</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="logger">
        <term><command>logger</command></term>
        <listitem>
          <para>Enters the given message into the system log</para>
          <indexterm zone="ch-system-util-linux logger">
            <primary sortas="b-logger">logger</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="look">
        <term><command>look</command></term>
        <listitem>
          <para>Displays lines that begin with the given string</para>
          <indexterm zone="ch-system-util-linux look">
            <primary sortas="b-look">look</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="losetup">
        <term><command>losetup</command></term>
        <listitem>
          <para>Sets up and controls loop devices</para>
          <indexterm zone="ch-system-util-linux losetup">
            <primary sortas="b-losetup">losetup</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="lscpu">
        <term><command>lscpu</command></term>
        <listitem>
          <para>Prints CPU architechture information</para>
          <indexterm zone="ch-system-util-linux lscpu">
            <primary sortas="b-lscpu">lscpu</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="mcookie">
        <term><command>mcookie</command></term>
        <listitem>
          <para>Generates magic cookies (128-bit random hexadecimal numbers) for
          <command>xauth</command></para>
          <indexterm zone="ch-system-util-linux mcookie">
            <primary sortas="b-mcookie">mcookie</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="mkfs">
        <term><command>mkfs</command></term>
        <listitem>
          <para>Builds a file system on a device (usually a hard disk
          partition)</para>
          <indexterm zone="ch-system-util-linux mkfs">
            <primary sortas="b-mkfs">mkfs</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="mkfs.bfs">
        <term><command>mkfs.bfs</command></term>
        <listitem>
          <para>Creates a Santa Cruz Operations (SCO) bfs file system</para>
          <indexterm zone="ch-system-util-linux mkfs.bfs">
            <primary sortas="b-mkfs.bfs">mkfs.bfs</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="mkfs.cramfs">
        <term><command>mkfs.cramfs</command></term>
        <listitem>
          <para>Creates a cramfs file system</para>
          <indexterm zone="ch-system-util-linux mkfs.cramfs">
            <primary sortas="b-mkfs.cramfs">mkfs.cramfs</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="mkfs.minix">
        <term><command>mkfs.minix</command></term>
        <listitem>
          <para>Creates a Minix file system</para>
          <indexterm zone="ch-system-util-linux mkfs.minix">
            <primary sortas="b-mkfs.minix">mkfs.minix</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="mkswap">
        <term><command>mkswap</command></term>
        <listitem>
          <para>Initializes the given device or file to be used as a swap
          area</para>
          <indexterm zone="ch-system-util-linux mkswap">
            <primary sortas="b-mkswap">mkswap</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="more">
        <term><command>more</command></term>
        <listitem>
          <para>A filter for paging through text one screen at a time</para>
          <indexterm zone="ch-system-util-linux more">
            <primary sortas="b-more">more</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="mount">
        <term><command>mount</command></term>
        <listitem>
          <para>Attaches the file system on the given device to a specified
          directory in the file-system tree</para>
          <indexterm zone="ch-system-util-linux mount">
            <primary sortas="b-mount">mount</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="namei">
        <term><command>namei</command></term>
        <listitem>
          <para>Shows the symbolic links in the given pathnames</para>
          <indexterm zone="ch-system-util-linux namei">
            <primary sortas="b-namei">namei</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="partx">
        <term><command>partx</command></term>
        <listitem>
          <para>Tells the kernel about the presence and numbering of on-disk
          partitions</para>
          <indexterm zone="ch-system-util-linux partx">
            <primary sortas="b-partx">partx</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="pg">
        <term><command>pg</command></term>
        <listitem>
          <para>Displays a text file one screen full at a time</para>
          <indexterm zone="ch-system-util-linux pg">
            <primary sortas="b-pg">pg</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="pivot_root">
        <term><command>pivot_root</command></term>
        <listitem>
          <para>Makes the given file system the new root file system of the
          current process</para>
          <indexterm zone="ch-system-util-linux pivot_root">
            <primary sortas="b-pivot_root">pivot_root</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="readprofile">
        <term><command>readprofile</command></term>
        <listitem>
          <para>Reads kernel profiling information</para>
          <indexterm zone="ch-system-util-linux readprofile">
            <primary sortas="b-readprofile">readprofile</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="rename">
        <term><command>rename</command></term>
        <listitem>
          <para>Renames the given files, replacing a given string with
          another</para>
          <indexterm zone="ch-system-util-linux rename">
            <primary sortas="b-rename">rename</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="renice">
        <term><command>renice</command></term>
        <listitem>
          <para>Alters the priority of running processes</para>
          <indexterm zone="ch-system-util-linux renice">
            <primary sortas="b-renice">renice</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="rev">
        <term><command>rev</command></term>
        <listitem>
          <para>Reverses the lines of a given file</para>
          <indexterm zone="ch-system-util-linux rev">
            <primary sortas="b-rev">rev</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="rtcwake">
        <term><command>rtcwake</command></term>
        <listitem>
          <para>Enters a system sleep state until a specified wakeup time</para>
          <indexterm zone="ch-system-util-linux rtcwake">
            <primary sortas="b-rtcwake">rtcwake</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="script">
        <term><command>script</command></term>
        <listitem>
          <para>Makes a typescript of a terminal session</para>
          <indexterm zone="ch-system-util-linux script">
            <primary sortas="b-script">script</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="scriptreplay">
        <term><command>scriptreplay</command></term>
        <listitem>
          <para>Plays back typescripts created by <command>script</command></para>
          <indexterm zone="ch-system-util-linux scriptreplay">
            <primary sortas="b-scriptreplay">scriptreplay</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="setarch">
        <term><command>setarch</command></term>
        <listitem>
          <para>Changes reported architecture in new program environment and
          sets personality flags</para>
          <indexterm zone="ch-system-util-linux setarch">
            <primary sortas="b-setarch">setarch</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="setsid">
        <term><command>setsid</command></term>
        <listitem>
          <para>Runs the given program in a new session</para>
          <indexterm zone="ch-system-util-linux setsid">
            <primary sortas="b-setsid">setsid</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="setterm">
        <term><command>setterm</command></term>
        <listitem>
          <para>Sets terminal attributes</para>
          <indexterm zone="ch-system-util-linux setterm">
            <primary sortas="b-setterm">setterm</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="sfdisk">
        <term><command>sfdisk</command></term>
        <listitem>
          <para>A disk partition table manipulator</para>
          <indexterm zone="ch-system-util-linux sfdisk">
            <primary sortas="b-sfdisk">sfdisk</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="swapoff">
        <term><command>swapoff</command></term>
        <listitem>
          <para>Disables devices and files for paging and swapping</para>
          <indexterm zone="ch-system-util-linux swapoff">
            <primary sortas="b-swapoff">swapoff</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="swapon">
        <term><command>swapon</command></term>
        <listitem>
          <para>Enables devices and files for paging and swapping and
          lists the devices and files currently in use</para>
          <indexterm zone="ch-system-util-linux swapon">
            <primary sortas="b-swapon">swapon</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="switch_root">
        <term><command>switch_root</command></term>
        <listitem>
          <para>Switches to another filesystem as the root of the mount tree</para>
          <indexterm zone="ch-system-util-linux switch_root">
            <primary sortas="b-switch_root">switch_root</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="tailf">
        <term><command>tailf</command></term>
        <listitem>
          <para>Tracks the growth of a log file. Displays the last 10 lines
          of a log file, then continues displaying any new entries in the
          log file as they are created</para>
          <indexterm zone="ch-system-util-linux tailf">
            <primary sortas="b-tailf">tailf</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="taskset">
        <term><command>taskset</command></term>
        <listitem>
          <para>Retrieves or sets a process's CPU affinity</para>
          <indexterm zone="ch-system-util-linux taskset">
            <primary sortas="b-taskset">taskset</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="tunelp">
        <term><command>tunelp</command></term>
        <listitem>
          <para>Tunes the parameters of the line printer</para>
          <indexterm zone="ch-system-util-linux tunelp">
            <primary sortas="b-tunelp">tunelp</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="ul">
        <term><command>ul</command></term>
        <listitem>
          <para>A filter for translating underscores into escape sequences
          indicating underlining for the terminal in use</para>
          <indexterm zone="ch-system-util-linux ul">
            <primary sortas="b-ul">ul</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="umount">
        <term><command>umount</command></term>
        <listitem>
          <para>Disconnects a file system from the system's file tree</para>
          <indexterm zone="ch-system-util-linux umount">
            <primary sortas="b-umount">umount</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="uuidd">
        <term><command>uuidd</command></term>
        <listitem>
          <para>A daemon used by the UUID library to generate time-based
          UUIDs in a secure and guranteed-unique fashion.</para>
          <indexterm zone="ch-system-util-linux uuidd">
            <primary sortas="b-uuidd">uuidd</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="uuidgen">
        <term><command>uuidgen</command></term>
        <listitem>
          <para>Creates new UUIDs. Each new UUID can reasonably be considered
          unique among all UUIDs created, on the local system and on other
          systems, in the past and in the future</para>
          <indexterm zone="ch-system-util-linux uuidgen">
            <primary sortas="b-uuidgen">uuidgen</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="whereis">
        <term><command>whereis</command></term>
        <listitem>
          <para>Reports the location of the binary, source, and man page
          for the given command</para>
          <indexterm zone="ch-system-util-linux whereis">
            <primary sortas="b-whereis">whereis</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="write">
        <term><command>write</command></term>
        <listitem>
          <para>Sends a message to the given user <emphasis>if</emphasis> that
          user has not disabled receipt of such messages</para>
          <indexterm zone="ch-system-util-linux write">
            <primary sortas="b-write">write</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="libblkid">
        <term><filename class="libraryfile">libblkid</filename></term>
        <listitem>
          <para>Contains routines for device identification and token
          extraction</para>
          <indexterm zone="ch-system-util-linux libblkid">
            <primary sortas="c-libblkid">libblkid</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="libuuid">
        <term><filename class="libraryfile">libuuid</filename></term>
        <listitem>
          <para>Contains routines for generating unique identifiers for objects
          that may be accessible beyond the local system</para>
          <indexterm zone="ch-system-util-linux libuuid">
            <primary sortas="c-libuuid">libuuid</primary>
          </indexterm>
        </listitem>
      </varlistentry>

    </variablelist>

  </sect2>

</sect1>