chapter06/glibc.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-glibc" role="wrap">
   9   <?dbhtml filename="glibc.html"?>
  10
  11   <sect1info condition="script">
  12     <productname>glibc</productname>
  13     <productnumber>&glibc-version;</productnumber>
  14     <address>&glibc-url;</address>
  15   </sect1info>
  16
  17   <title>Glibc-&glibc-version;</title>
  18
  19   <indexterm zone="ch-system-glibc">
  20     <primary sortas="a-Glibc">Glibc</primary>
  21   </indexterm>
  22
  23   <sect2 role="package">
  24     <title/>
  25
  26     <para>The Glibc package contains the main C library. This library provides
  27     the basic routines for allocating memory, searching directories, opening and
  28     closing files, reading and writing files, string handling, pattern matching,
  29     arithmetic, and so on.</para>
  30
  31     <segmentedlist>
  32       <segtitle>&buildtime;</segtitle>
  33       <segtitle>&diskspace;</segtitle>
  34
  35       <seglistitem>
  36         <seg>&glibc-ch6-sbu;</seg>
  37         <seg>&glibc-ch6-du;</seg>
  38       </seglistitem>
  39     </segmentedlist>
  40
  41   </sect2>
  42
  43   <sect2 role="installation">
  44     <title>Installation of Glibc</title>
  45
  46     <note><para>The Glibc build system is self-contained and will install
  47     perfectly, even though the compiler specs file and linker are still
  48     pointing to <filename class="directory">/tools</filename>. The specs
  49     and linker cannot be adjusted before the Glibc install because the
  50     Glibc autoconf tests would give false results and defeat the goal
  51     of achieving a clean build.</para></note>
  52
  53     <para>Some of the Glibc programs use non-FHS compilant
  54     <filename class="directory">/var/db</filename> directory to store
  55     their runtime data. Apply the following patch to make such programs
  56     store their runtime data in the FHS-compliant locations:</para>
  57
  58 <screen><userinput remap="pre">patch -Np1 -i ../&glibc-fhs-patch;</userinput></screen>
  59
  60     <para>The Glibc documentation recommends building Glibc
  61     in a dedicated build directory:</para>
  62
  63 <screen><userinput remap="pre">mkdir -v build
  64 cd       build</userinput></screen>
  65
  66     <para>Prepare Glibc for compilation:</para>
  67
  68 <screen><userinput remap="configure">../configure --prefix=/usr          \
  69              --enable-kernel=&min-kernel; \
  70              --enable-obsolete-rpc</userinput></screen>
  71
  72     <para>Compile the package:</para>
  73
  74 <screen><userinput remap="make">make</userinput></screen>
  75
  76     <important>
  77       <para>In this section, the test suite for Glibc is considered critical.
  78       Do not skip it under any circumstance.</para>
  79     </important>
  80
  81     <para>Generally a few tests do not pass, but you can generally ignore
  82     any of the test failures listed below. Now test the build results:</para>
  83
  84 <screen><userinput remap="test">make check</userinput></screen>
  85
  86     <para>You will probably see some test failures.  The Glibc test suite is
  87     somewhat dependent on the host system.  This is a list of the most common
  88     issues seen for this version of LFS:</para>
  89
  90     <itemizedlist>
  91
  92       <listitem>
  93         <para><emphasis>posix/tst-getaddrinfo4</emphasis> will always fail due
  94         to not having the necessary networking applications when the tests are
  95         run.  <emphasis>posix/tst-getaddrinfo5</emphasis> is also known
  96         to fail on some architectures.</para>
  97       </listitem>
  98
  99       <listitem>
 100         <para>The <emphasis>rt/tst-cputimer1</emphasis> and
 101         <emphasis>rt/tst-cpuclock2</emphasis> tests have been known to
 102         fail.  The reason is not completely understood, but indications are
 103         that minor timing issues can trigger these failures.</para>
 104       </listitem>
 105
 106       <listitem>
 107         <para>The math tests sometimes fail when running on
 108         systems where the CPU is not a relatively new Intel or
 109         AMD processor.</para>
 110       </listitem>
 111
 112       <listitem>
 113         <para>The
 114         <emphasis>nptl/tst-thread-affinity-{pthread,pthread2,sched}</emphasis>
 115         tests may fail for reasons that have not been determined.  </para>
 116       </listitem>
 117
 118       <listitem>
 119         <para>Other tests known to fail on some architectures are
 120         malloc/tst-malloc-usable and nptl/tst-cleanupx4. </para>
 121       </listitem>
 122
 123     </itemizedlist>
 124
 125     <para>Though it is a harmless message, the install stage of Glibc will
 126     complain about the absence of <filename>/etc/ld.so.conf</filename>.
 127     Prevent this warning with:</para>
 128
 129 <screen><userinput remap="install">touch /etc/ld.so.conf</userinput></screen>
 130
 131     <para>Install the package:</para>
 132
 133 <screen><userinput remap="install">make install</userinput></screen>
 134
 135     <para>Install the configuration file and runtime directory for
 136     <command>nscd</command>:</para>
 137
 138 <screen><userinput remap="install">cp -v ../nscd/nscd.conf /etc/nscd.conf
 139 mkdir -pv /var/cache/nscd</userinput></screen>
 140
 141     <para revision="systemd">Install the systemd support files for
 142     <command>nscd</command>:</para>
 143
 144     <screen revision="systemd"><userinput remap="install">install -v -Dm644 ../nscd/nscd.tmpfiles /usr/lib/tmpfiles.d/nscd.conf
 145 install -v -Dm644 ../nscd/nscd.service /lib/systemd/system/nscd.service</userinput></screen>
 146
 147     <para>Next, install the locales that can make the system respond in a
 148     different language.  None of the locales are required, but if some of them
 149     are missing, the test suites of future packages would skip important
 150     testcases.</para>
 151
 152     <para>Individual locales can be installed using the
 153     <command>localedef</command> program. E.g., the first
 154     <command>localedef</command> command below combines the
 155     <filename>/usr/share/i18n/locales/cs_CZ</filename>
 156     charset-independent locale definition with the
 157     <filename>/usr/share/i18n/charmaps/UTF-8.gz</filename>
 158     charmap definition and appends the result to the
 159     <filename>/usr/lib/locale/locale-archive</filename> file.
 160     The following instructions will install the minimum set of
 161     locales necessary for the optimal coverage of tests:</para>
 162
 163 <screen role="nodump"><userinput remap="locale-test">mkdir -pv /usr/lib/locale
 164 localedef -i cs_CZ -f UTF-8 cs_CZ.UTF-8
 165 localedef -i de_DE -f ISO-8859-1 de_DE
 166 localedef -i de_DE@euro -f ISO-8859-15 de_DE@euro
 167 localedef -i de_DE -f UTF-8 de_DE.UTF-8
 168 localedef -i en_GB -f UTF-8 en_GB.UTF-8
 169 localedef -i en_HK -f ISO-8859-1 en_HK
 170 localedef -i en_PH -f ISO-8859-1 en_PH
 171 localedef -i en_US -f ISO-8859-1 en_US
 172 localedef -i en_US -f UTF-8 en_US.UTF-8
 173 localedef -i es_MX -f ISO-8859-1 es_MX
 174 localedef -i fa_IR -f UTF-8 fa_IR
 175 localedef -i fr_FR -f ISO-8859-1 fr_FR
 176 localedef -i fr_FR@euro -f ISO-8859-15 fr_FR@euro
 177 localedef -i fr_FR -f UTF-8 fr_FR.UTF-8
 178 localedef -i it_IT -f ISO-8859-1 it_IT
 179 localedef -i it_IT -f UTF-8 it_IT.UTF-8
 180 localedef -i ja_JP -f EUC-JP ja_JP
 181 localedef -i ru_RU -f KOI8-R ru_RU.KOI8-R
 182 localedef -i ru_RU -f UTF-8 ru_RU.UTF-8
 183 localedef -i tr_TR -f UTF-8 tr_TR.UTF-8
 184 localedef -i zh_CN -f GB18030 zh_CN.GB18030</userinput></screen>
 185
 186     <para>In addition, install the locale for your own country, language and
 187     character set.</para>
 188
 189     <para>Alternatively, install all locales listed in the
 190     <filename>glibc-&glibc-version;/localedata/SUPPORTED</filename> file
 191     (it includes every locale listed above and many more) at once with the
 192     following time-consuming command:</para>
 193
 194 <screen><userinput remap="locale-full">make localedata/install-locales</userinput></screen>
 195
 196     <para>Then use the <command>localedef</command> command to create and
 197     install locales not listed in the
 198     <filename>glibc-&glibc-version;/localedata/SUPPORTED</filename> file
 199     in the unlikely case you need them.</para>
 200
 201   </sect2>
 202
 203   <sect2 id="conf-glibc" role="configuration">
 204     <title>Configuring Glibc</title>
 205
 206     <indexterm zone="conf-glibc">
 207       <primary sortas="e-/etc/nsswitch.conf">/etc/nsswitch.conf</primary>
 208     </indexterm>
 209
 210     <indexterm zone="conf-glibc">
 211       <primary sortas="e-/etc/localtime">/etc/localtime</primary>
 212     </indexterm>
 213
 214   <sect3>
 215   <title>Adding nsswitch.conf</title>
 216
 217     <para>The <filename>/etc/nsswitch.conf</filename> file needs to be created
 218     because the Glibc defaults do not work well in a networked environment.
 219     </para>
 220
 221     <para>Create a new file <filename>/etc/nsswitch.conf</filename> by running the
 222     following:</para>
 223
 224 <screen><userinput>cat &gt; /etc/nsswitch.conf &lt;&lt; "EOF"
 225 <literal># Begin /etc/nsswitch.conf
 226
 227 passwd: files
 228 group: files
 229 shadow: files
 230
 231 hosts: files dns
 232 networks: files
 233
 234 protocols: files
 235 services: files
 236 ethers: files
 237 rpc: files
 238
 239 # End /etc/nsswitch.conf</literal>
 240 EOF</userinput></screen>
 241
 242     </sect3>
 243
 244     <sect3>
 245     <title>Adding time zone data</title>
 246
 247     <para>Install and set up the time zone data with the following:</para>
 248 <screen><userinput>tar -xf ../../tzdata&tzdata-version;.tar.gz
 249
 250 ZONEINFO=/usr/share/zoneinfo
 251 mkdir -pv $ZONEINFO/{posix,right}
 252
 253 for tz in etcetera southamerica northamerica europe africa antarctica  \
 254           asia australasia backward pacificnew systemv; do
 255     zic -L /dev/null   -d $ZONEINFO       -y "sh yearistype.sh" ${tz}
 256     zic -L /dev/null   -d $ZONEINFO/posix -y "sh yearistype.sh" ${tz}
 257     zic -L leapseconds -d $ZONEINFO/right -y "sh yearistype.sh" ${tz}
 258 done
 259
 260 cp -v zone.tab zone1970.tab iso3166.tab $ZONEINFO
 261 zic -d $ZONEINFO -p America/New_York
 262 unset ZONEINFO</userinput></screen>
 263
 264     <variablelist>
 265       <title>The meaning of the zic commands:</title>
 266
 267       <varlistentry>
 268         <term><parameter>zic -L /dev/null ...</parameter></term>
 269         <listitem>
 270           <para>This creates posix time zones, without any leap seconds.  It is
 271           conventional to put these in both
 272           <filename class="directory">zoneinfo</filename> and
 273           <filename class="directory">zoneinfo/posix</filename>. It is
 274           necessary to put the POSIX time zones in
 275           <filename class="directory">zoneinfo</filename>, otherwise various
 276           test-suites will report errors. On an embedded system, where space is
 277           tight and you do not intend to ever update the time zones, you could save
 278           1.9MB by not using the <filename class="directory">posix</filename>
 279           directory, but some applications or test-suites might produce some
 280           failures.</para>
 281         </listitem>
 282       </varlistentry>
 283       <varlistentry>
 284         <term><parameter>zic -L leapseconds ...</parameter></term>
 285         <listitem>
 286           <para>This creates right time zones, including leap seconds. On an
 287           embedded system, where space is tight and you do not intend to
 288           ever update the time zones, or care about the correct time, you could
 289           save 1.9MB by omitting the <filename class="directory">right</filename>
 290           directory.</para>
 291         </listitem>
 292       </varlistentry>
 293       <varlistentry>
 294         <term><parameter>zic ... -p ...</parameter></term>
 295         <listitem>
 296           <para>This creates the <filename>posixrules</filename> file. We use
 297           New York because POSIX requires the daylight savings time rules
 298           to be in accordance with US rules.</para>
 299         </listitem>
 300       </varlistentry>
 301     </variablelist>
 302
 303
 304     <para>One way to determine the local time zone is to run the following
 305     script:</para>
 306
 307 <screen role="nodump"><userinput>tzselect</userinput></screen>
 308
 309     <para>After answering a few questions about the location, the script will
 310     output the name of the time zone (e.g.,
 311     <emphasis>America/Edmonton</emphasis>). There are also some other possible
 312     time zones listed in <filename
 313     class='directory'>/usr/share/zoneinfo</filename> such as
 314     <emphasis>Canada/Eastern</emphasis> or <emphasis>EST5EDT</emphasis> that
 315     are not identified by the script but can be used.</para>
 316
 317     <para>Then create the <filename>/etc/localtime</filename> file by
 318     running:</para>
 319
 320 <screen revision="sysv"><userinput>cp -v /usr/share/zoneinfo/<replaceable>&lt;xxx&gt;</replaceable> /etc/localtime</userinput></screen>
 321
 322 <screen revision="systemd"><userinput>ln -sfv /usr/share/zoneinfo/<replaceable>&lt;xxx&gt;</replaceable> /etc/localtime</userinput></screen>
 323
 324     <para>Replace <replaceable>&lt;xxx&gt;</replaceable> with the name of the
 325     time zone selected (e.g., Canada/Eastern).</para>
 326
 327   </sect3>
 328
 329   <sect3 id="conf-ld" role="configuration">
 330     <title>Configuring the Dynamic Loader</title>
 331
 332     <indexterm zone="conf-ld">
 333       <primary sortas="e-/etc/ld.so.conf">/etc/ld.so.conf</primary>
 334     </indexterm>
 335
 336     <para>By default, the dynamic loader (<filename
 337     class="libraryfile">/lib/ld-linux.so.2</filename>) searches through
 338     <filename class="directory">/lib</filename> and <filename
 339     class="directory">/usr/lib</filename> for dynamic libraries that are
 340     needed by programs as they are run. However, if there are libraries in
 341     directories other than <filename class="directory">/lib</filename> and
 342     <filename class="directory">/usr/lib</filename>, these need to be added
 343     to the <filename>/etc/ld.so.conf</filename> file in order for the
 344     dynamic loader to find them. Two directories that are commonly known
 345     to contain additional libraries are <filename
 346     class="directory">/usr/local/lib</filename> and <filename
 347     class="directory">/opt/lib</filename>, so add those directories to the
 348     dynamic loader's search path.</para>
 349
 350     <para>Create a new file <filename>/etc/ld.so.conf</filename> by running the
 351     following:</para>
 352
 353 <screen><userinput>cat &gt; /etc/ld.so.conf &lt;&lt; "EOF"
 354 <literal># Begin /etc/ld.so.conf
 355 /usr/local/lib
 356 /opt/lib
 357 </literal>
 358 EOF</userinput></screen>
 359
 360   <para>If desired, the dynamic loader can also search a directory and
 361   include the contents of files found there.  Generally the files in
 362   this include directory are one line specifying the desired library path.
 363   To add this capability run the following commands:</para>
 364
 365 <screen role="nodump"><userinput>cat &gt;&gt; /etc/ld.so.conf &lt;&lt; "EOF"
 366 <literal># Add an include directory
 367 include /etc/ld.so.conf.d/*.conf
 368 </literal>
 369 EOF
 370 mkdir -pv /etc/ld.so.conf.d</userinput></screen>
 371
 372   </sect3>
 373   </sect2>
 374
 375   <sect2 id="contents-glibc" role="content">
 376     <title>Contents of Glibc</title>
 377
 378     <segmentedlist>
 379       <segtitle>Installed programs</segtitle>
 380       <segtitle>Installed libraries</segtitle>
 381       <segtitle>Installed directories</segtitle>
 382
 383       <seglistitem>
 384         <seg>catchsegv, gencat, getconf, getent, iconv, iconvconfig, ldconfig,
 385         ldd, lddlibc4, locale, localedef, makedb, mtrace, nscd,
 386         pldd, rpcgen, sln, sotruss, sprof, tzselect, xtrace,
 387         zdump, and zic</seg>
 388         <seg>ld-&glibc-version;.so, libBrokenLocale.{a,so}, libSegFault.so, libanl.{a,so},
 389         libc.{a,so}, libc_nonshared.a, libcidn.so,
 390         libcrypt.{a,so}, libdl.{a,so}, libg.a, libieee.a, libm.{a,so},
 391         libmcheck.a, libmemusage.so, libnsl.{a,so}, libnss_compat.so,
 392         libnss_dns.so, libnss_files.so, libnss_hesiod.so, libnss_nis.so,
 393         libnss_nisplus.so, libpthread.{a,so},
 394         libpthread_nonshared.a, libresolv.{a,so}, librpcsvc.a, librt.{a,so},
 395         libthread_db.so, and libutil.{a,so}</seg>
 396         <seg>/usr/include/arpa, /usr/include/bits, /usr/include/gnu,
 397         /usr/include/net, /usr/include/netash, /usr/include/netatalk,
 398         /usr/include/netax25, /usr/include/neteconet, /usr/include/netinet,
 399         /usr/include/netipx, /usr/include/netiucv, /usr/include/netpacket,
 400         /usr/include/netrom, /usr/include/netrose, /usr/include/nfs,
 401         /usr/include/protocols, /usr/include/rpc, /usr/include/rpcsvc,
 402         /usr/include/sys, /usr/lib/audit, /usr/lib/gconv, /usr/lib/locale,
 403         /usr/libexec/getconf, /usr/share/i18n, /usr/share/zoneinfo,
 404         /var/cache/nscd, and /var/lib/nss_db</seg>
 405       </seglistitem>
 406     </segmentedlist>
 407
 408     <variablelist>
 409       <bridgehead renderas="sect3">Short Descriptions</bridgehead>
 410       <?dbfo list-presentation="list"?>
 411       <?dbhtml list-presentation="table"?>
 412
 413       <varlistentry id="catchsegv">
 414         <term><command>catchsegv</command></term>
 415         <listitem>
 416           <para>Can be used to create a stack trace when a program
 417           terminates with a segmentation fault</para>
 418           <indexterm zone="ch-system-glibc catchsegv">
 419             <primary sortas="b-catchsegv">catchsegv</primary>
 420           </indexterm>
 421         </listitem>
 422       </varlistentry>
 423
 424       <varlistentry id="gencat">
 425         <term><command>gencat</command></term>
 426         <listitem>
 427           <para>Generates message catalogues</para>
 428           <indexterm zone="ch-system-glibc gencat">
 429             <primary sortas="b-gencat">gencat</primary>
 430           </indexterm>
 431         </listitem>
 432       </varlistentry>
 433
 434       <varlistentry id="getconf">
 435         <term><command>getconf</command></term>
 436         <listitem>
 437           <para>Displays the system configuration values for file system
 438           specific variables</para>
 439           <indexterm zone="ch-system-glibc getconf">
 440             <primary sortas="b-getconf">getconf</primary>
 441           </indexterm>
 442         </listitem>
 443       </varlistentry>
 444
 445       <varlistentry id="getent">
 446         <term><command>getent</command></term>
 447         <listitem>
 448           <para>Gets entries from an administrative database</para>
 449           <indexterm zone="ch-system-glibc getent">
 450             <primary sortas="b-getent">getent</primary>
 451           </indexterm>
 452         </listitem>
 453       </varlistentry>
 454
 455       <varlistentry id="iconv">
 456         <term><command>iconv</command></term>
 457         <listitem>
 458           <para>Performs character set conversion</para>
 459           <indexterm zone="ch-system-glibc iconv">
 460             <primary sortas="b-iconv">iconv</primary>
 461           </indexterm>
 462         </listitem>
 463       </varlistentry>
 464
 465       <varlistentry id="iconvconfig">
 466         <term><command>iconvconfig</command></term>
 467         <listitem>
 468           <para>Creates fastloading <command>iconv</command> module configuration
 469           files</para>
 470           <indexterm zone="ch-system-glibc iconvconfig">
 471             <primary sortas="b-iconvconfig">iconvconfig</primary>
 472           </indexterm>
 473         </listitem>
 474       </varlistentry>
 475
 476       <varlistentry id="ldconfig">
 477         <term><command>ldconfig</command></term>
 478         <listitem>
 479           <para>Configures the dynamic linker runtime bindings</para>
 480           <indexterm zone="ch-system-glibc ldconfig">
 481             <primary sortas="b-ldconfig">ldconfig</primary>
 482           </indexterm>
 483         </listitem>
 484       </varlistentry>
 485
 486       <varlistentry id="ldd">
 487         <term><command>ldd</command></term>
 488         <listitem>
 489           <para>Reports which shared libraries are required
 490           by each given program or shared library</para>
 491           <indexterm zone="ch-system-glibc ldd">
 492             <primary sortas="b-ldd">ldd</primary>
 493           </indexterm>
 494         </listitem>
 495       </varlistentry>
 496
 497       <varlistentry id="lddlibc4">
 498         <term><command>lddlibc4</command></term>
 499         <listitem>
 500           <para>Assists <command>ldd</command> with object files</para>
 501           <indexterm zone="ch-system-glibc lddlibc4">
 502             <primary sortas="b-lddlibc4">lddlibc4</primary>
 503           </indexterm>
 504         </listitem>
 505       </varlistentry>
 506
 507       <varlistentry id="locale">
 508         <term><command>locale</command></term>
 509         <listitem>
 510           <para>Prints various information about the current locale</para>
 511           <indexterm zone="ch-system-glibc locale">
 512             <primary sortas="b-locale">locale</primary>
 513           </indexterm>
 514         </listitem>
 515       </varlistentry>
 516
 517       <varlistentry id="localedef">
 518         <term><command>localedef</command></term>
 519         <listitem>
 520           <para>Compiles locale specifications</para>
 521           <indexterm zone="ch-system-glibc localedef">
 522             <primary sortas="b-localedef">localedef</primary>
 523           </indexterm>
 524         </listitem>
 525       </varlistentry>
 526
 527       <varlistentry id="makedb">
 528         <term><command>makedb</command></term>
 529         <listitem>
 530           <para>Creates a simple database from textual input</para>
 531           <indexterm zone="ch-system-glibc makedb">
 532             <primary sortas="b-makedb">makedb</primary>
 533           </indexterm>
 534         </listitem>
 535       </varlistentry>
 536
 537       <varlistentry id="mtrace">
 538         <term><command>mtrace</command></term>
 539         <listitem>
 540           <para>Reads and interprets a memory trace file and displays a summary
 541           in human-readable format</para>
 542           <indexterm zone="ch-system-glibc mtrace">
 543             <primary sortas="b-mtrace">mtrace</primary>
 544           </indexterm>
 545         </listitem>
 546       </varlistentry>
 547
 548       <varlistentry id="nscd">
 549         <term><command>nscd</command></term>
 550         <listitem>
 551           <para>A daemon that provides a cache for the most common name
 552           service requests</para>
 553           <indexterm zone="ch-system-glibc nscd">
 554             <primary sortas="b-nscd">nscd</primary>
 555           </indexterm>
 556         </listitem>
 557       </varlistentry>
 558
 559       <varlistentry id="pldd">
 560         <term><command>pldd</command></term>
 561         <listitem>
 562           <para>Lists dynamic shared objects used by running processes</para>
 563           <indexterm zone="ch-system-glibc pldd">
 564             <primary sortas="b-pldd">pldd</primary>
 565           </indexterm>
 566         </listitem>
 567       </varlistentry>
 568
 569       <varlistentry id="rpcgen">
 570         <term><command>rpcgen</command></term>
 571         <listitem>
 572           <para>Generates C code to implement the Remote Procedure Call (RPC)
 573           protocol</para>
 574           <indexterm zone="ch-system-glibc rpcgen">
 575             <primary sortas="b-rpcgen">rpcgen</primary>
 576           </indexterm>
 577         </listitem>
 578       </varlistentry>
 579
 580       <varlistentry id="sln">
 581         <term><command>sln</command></term>
 582         <listitem>
 583           <para>A statically linked <command>ln</command> program</para>
 584           <indexterm zone="ch-system-glibc sln">
 585             <primary sortas="b-sln">sln</primary>
 586           </indexterm>
 587         </listitem>
 588       </varlistentry>
 589
 590       <varlistentry id="sotruss">
 591         <term><command>sotruss</command></term>
 592         <listitem>
 593           <para>Traces shared library procedure calls of a specified command</para>
 594           <indexterm zone="ch-system-glibc sotruss">
 595             <primary sortas="b-sotruss">sotruss</primary>
 596           </indexterm>
 597         </listitem>
 598       </varlistentry>
 599
 600       <varlistentry id="sprof">
 601         <term><command>sprof</command></term>
 602         <listitem>
 603           <para>Reads and displays shared object profiling data</para>
 604           <indexterm zone="ch-system-glibc sprof">
 605             <primary sortas="b-sprof">sprof</primary>
 606           </indexterm>
 607         </listitem>
 608       </varlistentry>
 609
 610       <varlistentry id="tzselect">
 611         <term><command>tzselect</command></term>
 612         <listitem>
 613           <para>Asks the user about the location of the system and reports
 614           the corresponding time zone description</para>
 615           <indexterm zone="ch-system-glibc tzselect">
 616             <primary sortas="b-tzselect">tzselect</primary>
 617           </indexterm>
 618         </listitem>
 619       </varlistentry>
 620
 621       <varlistentry id="xtrace">
 622         <term><command>xtrace</command></term>
 623         <listitem>
 624           <para>Traces the execution of a program by printing the currently
 625           executed function</para>
 626           <indexterm zone="ch-system-glibc xtrace">
 627             <primary sortas="b-xtrace">xtrace</primary>
 628           </indexterm>
 629         </listitem>
 630       </varlistentry>
 631
 632       <varlistentry id="zdump">
 633         <term><command>zdump</command></term>
 634         <listitem>
 635           <para>The time zone dumper</para>
 636           <indexterm zone="ch-system-glibc zdump">
 637             <primary sortas="b-zdump">zdump</primary>
 638           </indexterm>
 639         </listitem>
 640       </varlistentry>
 641
 642       <varlistentry id="zic">
 643         <term><command>zic</command></term>
 644         <listitem>
 645           <para>The time zone compiler</para>
 646           <indexterm zone="ch-system-glibc zic">
 647             <primary sortas="b-zic">zic</primary>
 648           </indexterm>
 649         </listitem>
 650       </varlistentry>
 651
 652       <varlistentry id="ld.so">
 653         <term><filename class="libraryfile">ld-&glibc-version;.so</filename></term>
 654         <listitem>
 655           <para>The helper program for shared library executables</para>
 656           <indexterm zone="ch-system-glibc ld.so">
 657             <primary sortas="c-ld.so">ld-&glibc-version;.so</primary>
 658           </indexterm>
 659         </listitem>
 660       </varlistentry>
 661
 662       <varlistentry id="libBrokenLocale">
 663         <term><filename class="libraryfile">libBrokenLocale</filename></term>
 664         <listitem>
 665           <para>Used internally by Glibc as a gross hack to get broken programs
 666           (e.g., some Motif applications) running. See comments in
 667           <filename>glibc-&glibc-version;/locale/broken_cur_max.c</filename>
 668           for more information</para>
 669           <indexterm zone="ch-system-glibc libBrokenLocale">
 670             <primary sortas="c-libBrokenLocale">libBrokenLocale</primary>
 671           </indexterm>
 672         </listitem>
 673       </varlistentry>
 674
 675       <varlistentry id="libSegFault">
 676         <term><filename class="libraryfile">libSegFault</filename></term>
 677         <listitem>
 678           <para>The segmentation fault signal handler, used by
 679           <command>catchsegv</command></para>
 680           <indexterm zone="ch-system-glibc libSegFault">
 681             <primary sortas="c-libSegFault">libSegFault</primary>
 682           </indexterm>
 683         </listitem>
 684       </varlistentry>
 685
 686       <varlistentry id="libanl">
 687         <term><filename class="libraryfile">libanl</filename></term>
 688         <listitem>
 689           <para>An asynchronous name lookup library</para>
 690           <indexterm zone="ch-system-glibc libanl">
 691             <primary sortas="c-libanl">libanl</primary>
 692           </indexterm>
 693         </listitem>
 694       </varlistentry>
 695
 696       <varlistentry id="libc">
 697         <term><filename class="libraryfile">libc</filename></term>
 698         <listitem>
 699           <para>The main C library</para>
 700           <indexterm zone="ch-system-glibc libc">
 701             <primary sortas="c-libc">libc</primary>
 702           </indexterm>
 703         </listitem>
 704       </varlistentry>
 705
 706       <varlistentry id="libcidn">
 707         <term><filename class="libraryfile">libcidn</filename></term>
 708         <listitem>
 709           <para>Used internally by Glibc for handling internationalized domain
 710           names in the <function>getaddrinfo()</function> function</para>
 711           <indexterm zone="ch-system-glibc libcidn">
 712             <primary sortas="c-libcidn">libcidn</primary>
 713           </indexterm>
 714         </listitem>
 715       </varlistentry>
 716
 717       <varlistentry id="libcrypt">
 718         <term><filename class="libraryfile">libcrypt</filename></term>
 719         <listitem>
 720           <para>The cryptography library</para>
 721           <indexterm zone="ch-system-glibc libcrypt">
 722             <primary sortas="c-libcrypt">libcrypt</primary>
 723           </indexterm>
 724         </listitem>
 725       </varlistentry>
 726
 727       <varlistentry id="libdl">
 728         <term><filename class="libraryfile">libdl</filename></term>
 729         <listitem>
 730           <para>The dynamic linking interface library</para>
 731           <indexterm zone="ch-system-glibc libdl">
 732             <primary sortas="c-libdl">libdl</primary>
 733           </indexterm>
 734         </listitem>
 735       </varlistentry>
 736
 737       <varlistentry id="libg">
 738         <term><filename class="libraryfile">libg</filename></term>
 739         <listitem>
 740           <para>Dummy library containing no functions. Previously was a runtime
 741           library for <command>g++</command></para>
 742           <indexterm zone="ch-system-glibc libg">
 743             <primary sortas="c-libg">libg</primary>
 744           </indexterm>
 745         </listitem>
 746       </varlistentry>
 747
 748       <varlistentry id="libieee">
 749         <term><filename class="libraryfile">libieee</filename></term>
 750         <listitem>
 751           <para>Linking in this module forces error handling rules for math
 752           functions as defined by the Institute of Electrical and Electronic
 753           Engineers (IEEE). The default is POSIX.1 error handling</para>
 754           <indexterm zone="ch-system-glibc libieee">
 755             <primary sortas="c-libieee">libieee</primary>
 756           </indexterm>
 757         </listitem>
 758       </varlistentry>
 759
 760       <varlistentry id="libm">
 761         <term><filename class="libraryfile">libm</filename></term>
 762         <listitem>
 763           <para>The mathematical library</para>
 764           <indexterm zone="ch-system-glibc libm">
 765             <primary sortas="c-libm">libm</primary>
 766           </indexterm>
 767         </listitem>
 768       </varlistentry>
 769
 770       <varlistentry id="libmcheck">
 771         <term><filename class="libraryfile">libmcheck</filename></term>
 772         <listitem>
 773           <para>Turns on memory allocation checking when linked to</para>
 774           <indexterm zone="ch-system-glibc libmcheck">
 775             <primary sortas="c-libmcheck">libmcheck</primary>
 776           </indexterm>
 777         </listitem>
 778       </varlistentry>
 779
 780       <varlistentry id="libmemusage">
 781         <term><filename class="libraryfile">libmemusage</filename></term>
 782         <listitem>
 783           <para>Used by <command>memusage</command> to help collect
 784           information about the memory usage of a program</para>
 785           <indexterm zone="ch-system-glibc libmemusage">
 786             <primary sortas="c-libmemusage">libmemusage</primary>
 787           </indexterm>
 788         </listitem>
 789       </varlistentry>
 790
 791       <varlistentry id="libnsl">
 792         <term><filename class="libraryfile">libnsl</filename></term>
 793         <listitem>
 794           <para>The network services library</para>
 795           <indexterm zone="ch-system-glibc libnsl">
 796             <primary sortas="c-libnsl">libnsl</primary>
 797           </indexterm>
 798         </listitem>
 799       </varlistentry>
 800
 801       <varlistentry id="libnss">
 802         <term><filename class="libraryfile">libnss</filename></term>
 803         <listitem>
 804           <para>The Name Service Switch libraries, containing functions for
 805           resolving host names, user names, group names, aliases, services,
 806           protocols, etc.</para>
 807           <indexterm zone="ch-system-glibc libnss">
 808             <primary sortas="c-libnss">libnss</primary>
 809           </indexterm>
 810         </listitem>
 811       </varlistentry>
 812
 813       <varlistentry id="libpthread">
 814         <term><filename class="libraryfile">libpthread</filename></term>
 815         <listitem>
 816           <para>The POSIX threads library</para>
 817           <indexterm zone="ch-system-glibc libpthread">
 818             <primary sortas="c-libpthread">libpthread</primary>
 819           </indexterm>
 820         </listitem>
 821       </varlistentry>
 822
 823       <varlistentry id="libresolv">
 824         <term><filename class="libraryfile">libresolv</filename></term>
 825         <listitem>
 826           <para>Contains functions for creating, sending, and interpreting
 827           packets to the Internet domain name servers</para>
 828           <indexterm zone="ch-system-glibc libresolv">
 829             <primary sortas="c-libresolv">libresolv</primary>
 830           </indexterm>
 831         </listitem>
 832       </varlistentry>
 833
 834       <varlistentry id="librpcsvc">
 835         <term><filename class="libraryfile">librpcsvc</filename></term>
 836         <listitem>
 837           <para>Contains functions providing miscellaneous RPC services</para>
 838           <indexterm zone="ch-system-glibc librpcsvc">
 839             <primary sortas="c-librpcsvc">librpcsvc</primary>
 840           </indexterm>
 841         </listitem>
 842       </varlistentry>
 843
 844       <varlistentry id="librt">
 845         <term><filename class="libraryfile">librt</filename></term>
 846         <listitem>
 847           <para>Contains functions providing most of the interfaces specified
 848           by the POSIX.1b Realtime Extension</para>
 849           <indexterm zone="ch-system-glibc librt">
 850             <primary sortas="c-librt">librt</primary>
 851           </indexterm>
 852         </listitem>
 853       </varlistentry>
 854
 855       <varlistentry id="libthread_db">
 856         <term><filename class="libraryfile">libthread_db</filename></term>
 857         <listitem>
 858           <para>Contains functions useful for building debuggers for
 859           multi-threaded programs</para>
 860           <indexterm zone="ch-system-glibc libthread_db">
 861             <primary sortas="c-libthread_db">libthread_db</primary>
 862           </indexterm>
 863         </listitem>
 864       </varlistentry>
 865
 866       <varlistentry id="libutil">
 867         <term><filename class="libraryfile">libutil</filename></term>
 868         <listitem>
 869           <para>Contains code for <quote>standard</quote> functions used in
 870           many different Unix utilities</para>
 871           <indexterm zone="ch-system-glibc libutil">
 872             <primary sortas="c-libutil">libutil</primary>
 873           </indexterm>
 874         </listitem>
 875       </varlistentry>
 876
 877     </variablelist>
 878
 879   </sect2>
 880
 881 </sect1>