BOOK/chapter08/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-fin-sbu;</seg>
  37         <seg>&glibc-fin-du;</seg>
  38       </seglistitem>
  39     </segmentedlist>
  40
  41   </sect2>
  42
  43   <sect2 role="installation">
  44     <title>Installation of Glibc</title>
  45
  46     <para>Some of the Glibc programs use the non-FHS compliant
  47     <filename class="directory">/var/db</filename> directory to store
  48     their runtime data. Apply the following patch to make such programs
  49     store their runtime data in the FHS-compliant locations:</para>
  50
  51 <screen><userinput remap="pre">patch -Np1 -i ../&glibc-fhs-patch;</userinput></screen>
  52
  53     <para>Fix a bug that causes issues with chrooted applications:</para>
  54
  55     <screen><userinput remap="pre">sed -e '402a\      *result = local->data.services[database_index];' \
  56     -i nss/nss_database.c</userinput></screen>
  57
  58     <para>The Glibc documentation recommends building Glibc
  59     in a dedicated build directory:</para>
  60
  61 <screen><userinput remap="pre">mkdir -v build
  62 cd       build</userinput></screen>
  63
  64     <para>Prepare Glibc for compilation:</para>
  65
  66 <screen><userinput remap="configure">../configure --prefix=/usr                            \
  67              --disable-werror                         \
  68              --enable-kernel=&min-kernel;                      \
  69              --enable-stack-protector=strong          \
  70              --with-headers=/usr/include              \
  71              libc_cv_slibdir=/lib</userinput></screen>
  72
  73     <variablelist>
  74       <title>The meaning of the configure options:</title>
  75
  76       <varlistentry>
  77         <term><parameter>--disable-werror</parameter></term>
  78         <listitem>
  79           <para>This option disables the -Werror option passed to
  80           GCC.  This is necessary for running the test suite.</para>
  81         </listitem>
  82       </varlistentry>
  83
  84       <varlistentry>
  85         <term><parameter>--enable-kernel=&min-kernel;</parameter></term>
  86         <listitem>
  87           <para>This option tells the build system that this glibc may
  88           be used with kernels as old as &min-kernel;. This means generating
  89           workarounds in case a system call introduced in a later version
  90           cannot be used.</para>
  91         </listitem>
  92       </varlistentry>
  93
  94       <varlistentry>
  95         <term><parameter>--enable-stack-protector=strong</parameter></term>
  96         <listitem>
  97           <para>This option increases system security by adding
  98           extra code to check for buffer overflows, such as stack
  99           smashing attacks.</para>
 100         </listitem>
 101       </varlistentry>
 102 <!-- do we need this one? -->
 103       <varlistentry>
 104         <term><parameter>--with-headers=/usr/include</parameter></term>
 105         <listitem>
 106           <para>This option tells the build system where to find the
 107           kernel API headers.</para>
 108         </listitem>
 109       </varlistentry>
 110
 111       <varlistentry>
 112         <term><parameter>libc_cv_slibdir=/lib</parameter></term>
 113         <listitem>
 114           <para>This variable sets the correct library for all
 115           systems.  We do not want lib64 to be used.</para>
 116         </listitem>
 117       </varlistentry>
 118
 119       <varlistentry>
 120         <term><option>libc_cv_include_x86_isa_level=no</option></term>
 121         <listitem>
 122           <para>This disables <quote>x86 ISA needed</quote> property in
 123           Glibc libraries.  Use it <emphasis role="bold">if</emphasis>
 124           you are building Glibc with <option>-march</option> option in
 125           <envar>CFLAGS</envar>, to workaround an issue in Glibc-2.33
 126           breaking it.</para>
 127         </listitem>
 128       </varlistentry>
 129
 130     </variablelist>
 131
 132     <para>Compile the package:</para>
 133
 134 <screen><userinput remap="make">make</userinput></screen>
 135
 136     <important>
 137       <para>In this section, the test suite for Glibc is considered critical.
 138       Do not skip it under any circumstance.</para>
 139     </important>
 140
 141     <para>Generally a few tests do not pass. The test failures listed below
 142     are usually safe to ignore.</para>
 143
 144 <!-- Use remap="make" here to work around a jhalfs issue. -->
 145 <!--<screen><userinput remap="make">case $(uname -m) in
 146   i?86)   ln -sfnv $PWD/elf/ld-linux.so.2        /lib ;;
 147   x86_64) ln -sfnv $PWD/elf/ld-linux-x86-64.so.2 /lib ;;
 148 esac</userinput></screen>
 149
 150     <note><para>The symbolic link above is needed to run the tests at this
 151     stage of building in the chroot environment.  It will be overwritten
 152     in the install phase below.</para></note>
 153 -->
 154 <screen><userinput remap="test">make check</userinput></screen>
 155
 156     <para>You may see some test failures.  The Glibc test suite is
 157     somewhat dependent on the host system.  This is a list of the most common
 158     issues seen for some versions of LFS:</para>
 159
 160     <itemizedlist>
 161
 162       <listitem>
 163         <para><emphasis>io/tst-lchmod</emphasis>
 164         is known to fail in the LFS chroot environment.</para>
 165       </listitem>
 166
 167       <listitem>
 168         <para><emphasis>misc/tst-ttyname</emphasis>
 169         is known to fail in the LFS chroot environment.</para>
 170       </listitem>
 171
 172       <listitem>
 173         <para><emphasis>elf/tst-cpu-features-cpuinfo</emphasis>
 174         may fail on some architectures.</para>
 175       </listitem>
 176
 177       <listitem>
 178         <para>The <emphasis>nss/tst-nss-files-hosts-multi</emphasis>
 179         test may fail for reasons that have not been determined.</para>
 180       </listitem>
 181
 182       <listitem>
 183         <para>The <emphasis>rt/tst-cputimer{1,2,3}</emphasis> tests depend on
 184         the host system kernel. Kernels 4.14.91&ndash;4.14.96,
 185         4.19.13&ndash;4.19.18, and 4.20.0&ndash;4.20.5 are known to
 186         cause these tests to fail.
 187         </para>
 188       </listitem>
 189
 190       <listitem>
 191         <para>The math tests sometimes fail when running on
 192         systems where the CPU is not a relatively new Intel or
 193         AMD processor.</para>
 194       </listitem>
 195
 196     </itemizedlist>
 197
 198     <para>Though it is a harmless message, the install stage of Glibc will
 199     complain about the absence of <filename>/etc/ld.so.conf</filename>.
 200     Prevent this warning with:</para>
 201
 202 <screen><userinput remap="install">touch /etc/ld.so.conf</userinput></screen>
 203
 204     <para>Fix the generated Makefile to skip an unneeded sanity check
 205     that fails in the LFS partial environment:
 206     </para>
 207
 208 <screen><userinput remap="install">sed '/test-installation/s@$(PERL)@echo not running@' -i ../Makefile</userinput></screen>
 209
 210     <para>Install the package:</para>
 211
 212 <screen><userinput remap="install">make install</userinput></screen>
 213
 214     <para>Install the configuration file and runtime directory for
 215     <command>nscd</command>:</para>
 216
 217 <screen><userinput remap="install">cp -v ../nscd/nscd.conf /etc/nscd.conf
 218 mkdir -pv /var/cache/nscd</userinput></screen>
 219
 220     <para revision="systemd">Install the systemd support files for
 221     <command>nscd</command>:</para>
 222
 223     <screen revision="systemd"><userinput remap="install">install -v -Dm644 ../nscd/nscd.tmpfiles /usr/lib/tmpfiles.d/nscd.conf
 224 install -v -Dm644 ../nscd/nscd.service /lib/systemd/system/nscd.service</userinput></screen>
 225
 226     <para>Next, install the locales that can make the system respond in a
 227     different language.  None of the locales are required, but if some of them
 228     are missing, the test suites of future packages would skip important
 229     testcases.</para>
 230
 231     <para>Individual locales can be installed using the
 232     <command>localedef</command> program. E.g., the first
 233     <command>localedef</command> command below combines the
 234     <filename>/usr/share/i18n/locales/cs_CZ</filename>
 235     charset-independent locale definition with the
 236     <filename>/usr/share/i18n/charmaps/UTF-8.gz</filename>
 237     charmap definition and appends the result to the
 238     <filename>/usr/lib/locale/locale-archive</filename> file.
 239     The following instructions will install the minimum set of
 240     locales necessary for the optimal coverage of tests:</para>
 241
 242 <screen role="nodump"><userinput remap="locale-test">mkdir -pv /usr/lib/locale
 243 localedef -i POSIX -f UTF-8 C.UTF-8 2> /dev/null || true
 244 localedef -i cs_CZ -f UTF-8 cs_CZ.UTF-8
 245 localedef -i de_DE -f ISO-8859-1 de_DE
 246 localedef -i de_DE@euro -f ISO-8859-15 de_DE@euro
 247 localedef -i de_DE -f UTF-8 de_DE.UTF-8
 248 localedef -i el_GR -f ISO-8859-7 el_GR
 249 localedef -i en_GB -f UTF-8 en_GB.UTF-8
 250 localedef -i en_HK -f ISO-8859-1 en_HK
 251 localedef -i en_PH -f ISO-8859-1 en_PH
 252 localedef -i en_US -f ISO-8859-1 en_US
 253 localedef -i en_US -f UTF-8 en_US.UTF-8
 254 localedef -i es_MX -f ISO-8859-1 es_MX
 255 localedef -i fa_IR -f UTF-8 fa_IR
 256 localedef -i fr_FR -f ISO-8859-1 fr_FR
 257 localedef -i fr_FR@euro -f ISO-8859-15 fr_FR@euro
 258 localedef -i fr_FR -f UTF-8 fr_FR.UTF-8
 259 localedef -i it_IT -f ISO-8859-1 it_IT
 260 localedef -i it_IT -f UTF-8 it_IT.UTF-8
 261 localedef -i ja_JP -f EUC-JP ja_JP
 262 localedef -i ja_JP -f SHIFT_JIS ja_JP.SIJS 2> /dev/null || true
 263 localedef -i ja_JP -f UTF-8 ja_JP.UTF-8
 264 localedef -i ru_RU -f KOI8-R ru_RU.KOI8-R
 265 localedef -i ru_RU -f UTF-8 ru_RU.UTF-8
 266 localedef -i tr_TR -f UTF-8 tr_TR.UTF-8
 267 localedef -i zh_CN -f GB18030 zh_CN.GB18030
 268 localedef -i zh_HK -f BIG5-HKSCS zh_HK.BIG5-HKSCS</userinput></screen>
 269
 270     <para>In addition, install the locale for your own country, language and
 271     character set.</para>
 272
 273     <para>Alternatively, install all locales listed in the
 274     <filename>glibc-&glibc-version;/localedata/SUPPORTED</filename> file
 275     (it includes every locale listed above and many more) at once with the
 276     following time-consuming command:</para>
 277
 278 <screen><userinput remap="locale-full">make localedata/install-locales</userinput></screen>
 279
 280     <para>Then use the <command>localedef</command> command to create and
 281     install locales not listed in the
 282     <filename>glibc-&glibc-version;/localedata/SUPPORTED</filename> file
 283     in the unlikely case you need them.</para>
 284
 285     <note><para>Glibc now uses libidn2 when resolving internationalized
 286     domain names.  This is a run time dependency.  If this capability
 287     is needed, the instructions for installing libidn2 are in the
 288     <ulink url="&blfs-book;general/libidn2.html">BLFS libidn2 page</ulink>.
 289     </para></note>
 290
 291   </sect2>
 292
 293   <sect2 id="conf-glibc" role="configuration">
 294     <title>Configuring Glibc</title>
 295
 296     <indexterm zone="conf-glibc">
 297       <primary sortas="e-/etc/nsswitch.conf">/etc/nsswitch.conf</primary>
 298     </indexterm>
 299
 300     <indexterm zone="conf-glibc">
 301       <primary sortas="e-/etc/localtime">/etc/localtime</primary>
 302     </indexterm>
 303
 304   <sect3>
 305   <title>Adding nsswitch.conf</title>
 306
 307     <para>The <filename>/etc/nsswitch.conf</filename> file needs to be created
 308     because the Glibc defaults do not work well in a networked environment.
 309     </para>
 310
 311     <para>Create a new file <filename>/etc/nsswitch.conf</filename> by running the
 312     following:</para>
 313
 314 <screen><userinput>cat &gt; /etc/nsswitch.conf &lt;&lt; "EOF"
 315 <literal># Begin /etc/nsswitch.conf
 316
 317 passwd: files
 318 group: files
 319 shadow: files
 320
 321 hosts: files dns
 322 networks: files
 323
 324 protocols: files
 325 services: files
 326 ethers: files
 327 rpc: files
 328
 329 # End /etc/nsswitch.conf</literal>
 330 EOF</userinput></screen>
 331
 332     </sect3>
 333
 334     <sect3>
 335     <title>Adding time zone data</title>
 336
 337     <para>Install and set up the time zone data with the following:</para>
 338 <screen><userinput>tar -xf ../../tzdata&tzdata-version;.tar.gz
 339
 340 ZONEINFO=/usr/share/zoneinfo
 341 mkdir -pv $ZONEINFO/{posix,right}
 342
 343 for tz in etcetera southamerica northamerica europe africa antarctica  \
 344           asia australasia backward; do
 345     zic -L /dev/null   -d $ZONEINFO       ${tz}
 346     zic -L /dev/null   -d $ZONEINFO/posix ${tz}
 347     zic -L leapseconds -d $ZONEINFO/right ${tz}
 348 done
 349
 350 cp -v zone.tab zone1970.tab iso3166.tab $ZONEINFO
 351 zic -d $ZONEINFO -p America/New_York
 352 unset ZONEINFO</userinput></screen>
 353
 354     <variablelist>
 355       <title>The meaning of the zic commands:</title>
 356
 357       <varlistentry>
 358         <term><parameter>zic -L /dev/null ...</parameter></term>
 359         <listitem>
 360           <para>This creates posix time zones without any leap seconds.  It is
 361           conventional to put these in both
 362           <filename class="directory">zoneinfo</filename> and
 363           <filename class="directory">zoneinfo/posix</filename>. It is
 364           necessary to put the POSIX time zones in
 365           <filename class="directory">zoneinfo</filename>, otherwise various
 366           test-suites will report errors. On an embedded system, where space is
 367           tight and you do not intend to ever update the time zones, you could save
 368           1.9 MB by not using the <filename class="directory">posix</filename>
 369           directory, but some applications or test-suites might produce some
 370           failures.</para>
 371         </listitem>
 372       </varlistentry>
 373       <varlistentry>
 374         <term><parameter>zic -L leapseconds ...</parameter></term>
 375         <listitem>
 376           <para>This creates right time zones, including leap seconds. On an
 377           embedded system, where space is tight and you do not intend to
 378           ever update the time zones, or care about the correct time, you could
 379           save 1.9MB by omitting the <filename class="directory">right</filename>
 380           directory.</para>
 381         </listitem>
 382       </varlistentry>
 383       <varlistentry>
 384         <term><parameter>zic ... -p ...</parameter></term>
 385         <listitem>
 386           <para>This creates the <filename>posixrules</filename> file. We use
 387           New York because POSIX requires the daylight savings time rules
 388           to be in accordance with US rules.</para>
 389         </listitem>
 390       </varlistentry>
 391     </variablelist>
 392
 393
 394     <para>One way to determine the local time zone is to run the following
 395     script:</para>
 396
 397 <screen role="nodump"><userinput>tzselect</userinput></screen>
 398
 399     <para>After answering a few questions about the location, the script will
 400     output the name of the time zone (e.g.,
 401     <emphasis>America/Edmonton</emphasis>). There are also some other possible
 402     time zones listed in <filename
 403     class='directory'>/usr/share/zoneinfo</filename> such as
 404     <emphasis>Canada/Eastern</emphasis> or <emphasis>EST5EDT</emphasis> that
 405     are not identified by the script but can be used.</para>
 406
 407     <para>Then create the <filename>/etc/localtime</filename> file by
 408     running:</para>
 409
 410 <screen><userinput>ln -sfv /usr/share/zoneinfo/<replaceable>&lt;xxx&gt;</replaceable> /etc/localtime</userinput></screen>
 411
 412     <para>Replace <replaceable>&lt;xxx&gt;</replaceable> with the name of the
 413     time zone selected (e.g., Canada/Eastern).</para>
 414
 415   </sect3>
 416
 417   <sect3 id="conf-ld" role="configuration">
 418     <title>Configuring the Dynamic Loader</title>
 419
 420     <indexterm zone="conf-ld">
 421       <primary sortas="e-/etc/ld.so.conf">/etc/ld.so.conf</primary>
 422     </indexterm>
 423
 424     <para>By default, the dynamic loader (<filename
 425     class="libraryfile">/lib/ld-linux.so.2</filename>) searches through
 426     <filename class="directory">/lib</filename> and <filename
 427     class="directory">/usr/lib</filename> for dynamic libraries that are
 428     needed by programs as they are run. However, if there are libraries in
 429     directories other than <filename class="directory">/lib</filename> and
 430     <filename class="directory">/usr/lib</filename>, these need to be added
 431     to the <filename>/etc/ld.so.conf</filename> file in order for the
 432     dynamic loader to find them. Two directories that are commonly known
 433     to contain additional libraries are <filename
 434     class="directory">/usr/local/lib</filename> and <filename
 435     class="directory">/opt/lib</filename>, so add those directories to the
 436     dynamic loader's search path.</para>
 437
 438     <para>Create a new file <filename>/etc/ld.so.conf</filename> by running the
 439     following:</para>
 440
 441 <screen><userinput>cat &gt; /etc/ld.so.conf &lt;&lt; "EOF"
 442 <literal># Begin /etc/ld.so.conf
 443 /usr/local/lib
 444 /opt/lib
 445 </literal>
 446 EOF</userinput></screen>
 447
 448   <para>If desired, the dynamic loader can also search a directory and
 449   include the contents of files found there.  Generally the files in
 450   this include directory are one line specifying the desired library path.
 451   To add this capability run the following commands:</para>
 452
 453 <screen role="nodump"><userinput>cat &gt;&gt; /etc/ld.so.conf &lt;&lt; "EOF"
 454 <literal># Add an include directory
 455 include /etc/ld.so.conf.d/*.conf
 456 </literal>
 457 EOF
 458 mkdir -pv /etc/ld.so.conf.d</userinput></screen>
 459
 460   </sect3>
 461   </sect2>
 462
 463   <sect2 id="contents-glibc" role="content">
 464     <title>Contents of Glibc</title>
 465
 466     <segmentedlist>
 467       <segtitle>Installed programs</segtitle>
 468       <segtitle>Installed libraries</segtitle>
 469       <segtitle>Installed directories</segtitle>
 470
 471       <seglistitem>
 472         <seg>catchsegv, gencat, getconf, getent, iconv, iconvconfig, ldconfig,
 473         ldd, lddlibc4, locale, localedef, makedb, mtrace, nscd,
 474         pcprofiledump, pldd, sln, sotruss, sprof, tzselect, xtrace,
 475         zdump, and zic</seg>
 476         <seg>ld-&glibc-version;.so, libBrokenLocale.{a,so}, libSegFault.so, libanl.{a,so},
 477         libc.{a,so}, libc_nonshared.a,
 478         libcrypt.{a,so}, libdl.{a,so}, libg.a, libm.{a,so},
 479         libmcheck.a, libmemusage.so, libmvec.{a,so}, libnsl.{a,so},
 480         libnss_compat.so, libnss_dns.so, libnss_files.so, libnss_hesiod.so,
 481         libpcprofile.so, libpthread.{a,so},
 482         libpthread_nonshared.a, libresolv.{a,so}, librt.{a,so},
 483         libthread_db.so, and libutil.{a,so}</seg>
 484         <seg>/usr/include/arpa, /usr/include/bits, /usr/include/gnu,
 485         /usr/include/net, /usr/include/netash, /usr/include/netatalk,
 486         /usr/include/netax25, /usr/include/neteconet, /usr/include/netinet,
 487         /usr/include/netipx, /usr/include/netiucv, /usr/include/netpacket,
 488         /usr/include/netrom, /usr/include/netrose, /usr/include/nfs,
 489         /usr/include/protocols, /usr/include/rpc,
 490         /usr/include/sys, /usr/lib/audit, /usr/lib/gconv, /usr/lib/locale,
 491         /usr/libexec/getconf, /usr/share/i18n, /usr/share/zoneinfo,
 492         /var/cache/nscd, and /var/lib/nss_db</seg>
 493       </seglistitem>
 494     </segmentedlist>
 495
 496     <variablelist>
 497       <bridgehead renderas="sect3">Short Descriptions</bridgehead>
 498       <?dbfo list-presentation="list"?>
 499       <?dbhtml list-presentation="table"?>
 500
 501       <varlistentry id="catchsegv">
 502         <term><command>catchsegv</command></term>
 503         <listitem>
 504           <para>Can be used to create a stack trace when a program
 505           terminates with a segmentation fault</para>
 506           <indexterm zone="ch-system-glibc catchsegv">
 507             <primary sortas="b-catchsegv">catchsegv</primary>
 508           </indexterm>
 509         </listitem>
 510       </varlistentry>
 511
 512       <varlistentry id="gencat">
 513         <term><command>gencat</command></term>
 514         <listitem>
 515           <para>Generates message catalogues</para>
 516           <indexterm zone="ch-system-glibc gencat">
 517             <primary sortas="b-gencat">gencat</primary>
 518           </indexterm>
 519         </listitem>
 520       </varlistentry>
 521
 522       <varlistentry id="getconf">
 523         <term><command>getconf</command></term>
 524         <listitem>
 525           <para>Displays the system configuration values for file system
 526           specific variables</para>
 527           <indexterm zone="ch-system-glibc getconf">
 528             <primary sortas="b-getconf">getconf</primary>
 529           </indexterm>
 530         </listitem>
 531       </varlistentry>
 532
 533       <varlistentry id="getent">
 534         <term><command>getent</command></term>
 535         <listitem>
 536           <para>Gets entries from an administrative database</para>
 537           <indexterm zone="ch-system-glibc getent">
 538             <primary sortas="b-getent">getent</primary>
 539           </indexterm>
 540         </listitem>
 541       </varlistentry>
 542
 543       <varlistentry id="iconv">
 544         <term><command>iconv</command></term>
 545         <listitem>
 546           <para>Performs character set conversion</para>
 547           <indexterm zone="ch-system-glibc iconv">
 548             <primary sortas="b-iconv">iconv</primary>
 549           </indexterm>
 550         </listitem>
 551       </varlistentry>
 552
 553       <varlistentry id="iconvconfig">
 554         <term><command>iconvconfig</command></term>
 555         <listitem>
 556           <para>Creates fastloading <command>iconv</command> module configuration
 557           files</para>
 558           <indexterm zone="ch-system-glibc iconvconfig">
 559             <primary sortas="b-iconvconfig">iconvconfig</primary>
 560           </indexterm>
 561         </listitem>
 562       </varlistentry>
 563
 564       <varlistentry id="ldconfig">
 565         <term><command>ldconfig</command></term>
 566         <listitem>
 567           <para>Configures the dynamic linker runtime bindings</para>
 568           <indexterm zone="ch-system-glibc ldconfig">
 569             <primary sortas="b-ldconfig">ldconfig</primary>
 570           </indexterm>
 571         </listitem>
 572       </varlistentry>
 573
 574       <varlistentry id="ldd">
 575         <term><command>ldd</command></term>
 576         <listitem>
 577           <para>Reports which shared libraries are required
 578           by each given program or shared library</para>
 579           <indexterm zone="ch-system-glibc ldd">
 580             <primary sortas="b-ldd">ldd</primary>
 581           </indexterm>
 582         </listitem>
 583       </varlistentry>
 584
 585       <varlistentry id="lddlibc4">
 586         <term><command>lddlibc4</command></term>
 587         <listitem>
 588           <para>Assists <command>ldd</command> with object files</para>
 589           <indexterm zone="ch-system-glibc lddlibc4">
 590             <primary sortas="b-lddlibc4">lddlibc4</primary>
 591           </indexterm>
 592         </listitem>
 593       </varlistentry>
 594
 595       <varlistentry id="locale">
 596         <term><command>locale</command></term>
 597         <listitem>
 598           <para>Prints various information about the current locale</para>
 599           <indexterm zone="ch-system-glibc locale">
 600             <primary sortas="b-locale">locale</primary>
 601           </indexterm>
 602         </listitem>
 603       </varlistentry>
 604
 605       <varlistentry id="localedef">
 606         <term><command>localedef</command></term>
 607         <listitem>
 608           <para>Compiles locale specifications</para>
 609           <indexterm zone="ch-system-glibc localedef">
 610             <primary sortas="b-localedef">localedef</primary>
 611           </indexterm>
 612         </listitem>
 613       </varlistentry>
 614
 615       <varlistentry id="makedb">
 616         <term><command>makedb</command></term>
 617         <listitem>
 618           <para>Creates a simple database from textual input</para>
 619           <indexterm zone="ch-system-glibc makedb">
 620             <primary sortas="b-makedb">makedb</primary>
 621           </indexterm>
 622         </listitem>
 623       </varlistentry>
 624
 625       <varlistentry id="mtrace">
 626         <term><command>mtrace</command></term>
 627         <listitem>
 628           <para>Reads and interprets a memory trace file and displays a summary
 629           in human-readable format</para>
 630           <indexterm zone="ch-system-glibc mtrace">
 631             <primary sortas="b-mtrace">mtrace</primary>
 632           </indexterm>
 633         </listitem>
 634       </varlistentry>
 635
 636       <varlistentry id="nscd">
 637         <term><command>nscd</command></term>
 638         <listitem>
 639           <para>A daemon that provides a cache for the most common name
 640           service requests</para>
 641           <indexterm zone="ch-system-glibc nscd">
 642             <primary sortas="b-nscd">nscd</primary>
 643           </indexterm>
 644         </listitem>
 645       </varlistentry>
 646
 647       <varlistentry id="pcprofiledump">
 648         <term><command>pcprofiledump</command></term>
 649         <listitem>
 650           <para>Dump information generated by PC profiling</para>
 651           <indexterm zone="ch-system-glibc pcprofiledump">
 652             <primary sortas="b-pcprofiledump">pcprofiledump</primary>
 653           </indexterm>
 654         </listitem>
 655       </varlistentry>
 656
 657       <varlistentry id="pldd">
 658         <term><command>pldd</command></term>
 659         <listitem>
 660           <para>Lists dynamic shared objects used by running processes</para>
 661           <indexterm zone="ch-system-glibc pldd">
 662             <primary sortas="b-pldd">pldd</primary>
 663           </indexterm>
 664         </listitem>
 665       </varlistentry>
 666
 667       <varlistentry id="sln">
 668         <term><command>sln</command></term>
 669         <listitem>
 670           <para>A statically linked <command>ln</command> program</para>
 671           <indexterm zone="ch-system-glibc sln">
 672             <primary sortas="b-sln">sln</primary>
 673           </indexterm>
 674         </listitem>
 675       </varlistentry>
 676
 677       <varlistentry id="sotruss">
 678         <term><command>sotruss</command></term>
 679         <listitem>
 680           <para>Traces shared library procedure calls of a specified command</para>
 681           <indexterm zone="ch-system-glibc sotruss">
 682             <primary sortas="b-sotruss">sotruss</primary>
 683           </indexterm>
 684         </listitem>
 685       </varlistentry>
 686
 687       <varlistentry id="sprof">
 688         <term><command>sprof</command></term>
 689         <listitem>
 690           <para>Reads and displays shared object profiling data</para>
 691           <indexterm zone="ch-system-glibc sprof">
 692             <primary sortas="b-sprof">sprof</primary>
 693           </indexterm>
 694         </listitem>
 695       </varlistentry>
 696
 697       <varlistentry id="tzselect">
 698         <term><command>tzselect</command></term>
 699         <listitem>
 700           <para>Asks the user about the location of the system and reports
 701           the corresponding time zone description</para>
 702           <indexterm zone="ch-system-glibc tzselect">
 703             <primary sortas="b-tzselect">tzselect</primary>
 704           </indexterm>
 705         </listitem>
 706       </varlistentry>
 707
 708       <varlistentry id="xtrace">
 709         <term><command>xtrace</command></term>
 710         <listitem>
 711           <para>Traces the execution of a program by printing the currently
 712           executed function</para>
 713           <indexterm zone="ch-system-glibc xtrace">
 714             <primary sortas="b-xtrace">xtrace</primary>
 715           </indexterm>
 716         </listitem>
 717       </varlistentry>
 718
 719       <varlistentry id="zdump">
 720         <term><command>zdump</command></term>
 721         <listitem>
 722           <para>The time zone dumper</para>
 723           <indexterm zone="ch-system-glibc zdump">
 724             <primary sortas="b-zdump">zdump</primary>
 725           </indexterm>
 726         </listitem>
 727       </varlistentry>
 728
 729       <varlistentry id="zic">
 730         <term><command>zic</command></term>
 731         <listitem>
 732           <para>The time zone compiler</para>
 733           <indexterm zone="ch-system-glibc zic">
 734             <primary sortas="b-zic">zic</primary>
 735           </indexterm>
 736         </listitem>
 737       </varlistentry>
 738
 739       <varlistentry id="ld.so">
 740         <term><filename class="libraryfile">ld-&glibc-version;.so</filename></term>
 741         <listitem>
 742           <para>The helper program for shared library executables</para>
 743           <indexterm zone="ch-system-glibc ld.so">
 744             <primary sortas="c-ld.so">ld-&glibc-version;.so</primary>
 745           </indexterm>
 746         </listitem>
 747       </varlistentry>
 748
 749       <varlistentry id="libBrokenLocale">
 750         <term><filename class="libraryfile">libBrokenLocale</filename></term>
 751         <listitem>
 752           <para>Used internally by Glibc as a gross hack to get broken programs
 753           (e.g., some Motif applications) running. See comments in
 754           <filename>glibc-&glibc-version;/locale/broken_cur_max.c</filename>
 755           for more information</para>
 756           <indexterm zone="ch-system-glibc libBrokenLocale">
 757             <primary sortas="c-libBrokenLocale">libBrokenLocale</primary>
 758           </indexterm>
 759         </listitem>
 760       </varlistentry>
 761
 762       <varlistentry id="libSegFault">
 763         <term><filename class="libraryfile">libSegFault</filename></term>
 764         <listitem>
 765           <para>The segmentation fault signal handler, used by
 766           <command>catchsegv</command></para>
 767           <indexterm zone="ch-system-glibc libSegFault">
 768             <primary sortas="c-libSegFault">libSegFault</primary>
 769           </indexterm>
 770         </listitem>
 771       </varlistentry>
 772
 773       <varlistentry id="libanl">
 774         <term><filename class="libraryfile">libanl</filename></term>
 775         <listitem>
 776           <para>An asynchronous name lookup library</para>
 777           <indexterm zone="ch-system-glibc libanl">
 778             <primary sortas="c-libanl">libanl</primary>
 779           </indexterm>
 780         </listitem>
 781       </varlistentry>
 782
 783       <varlistentry id="libc">
 784         <term><filename class="libraryfile">libc</filename></term>
 785         <listitem>
 786           <para>The main C library</para>
 787           <indexterm zone="ch-system-glibc libc">
 788             <primary sortas="c-libc">libc</primary>
 789           </indexterm>
 790         </listitem>
 791       </varlistentry>
 792
 793       <varlistentry id="libcrypt">
 794         <term><filename class="libraryfile">libcrypt</filename></term>
 795         <listitem>
 796           <para>The cryptography library</para>
 797           <indexterm zone="ch-system-glibc libcrypt">
 798             <primary sortas="c-libcrypt">libcrypt</primary>
 799           </indexterm>
 800         </listitem>
 801       </varlistentry>
 802
 803       <varlistentry id="libdl">
 804         <term><filename class="libraryfile">libdl</filename></term>
 805         <listitem>
 806           <para>The dynamic linking interface library</para>
 807           <indexterm zone="ch-system-glibc libdl">
 808             <primary sortas="c-libdl">libdl</primary>
 809           </indexterm>
 810         </listitem>
 811       </varlistentry>
 812
 813       <varlistentry id="libg">
 814         <term><filename class="libraryfile">libg</filename></term>
 815         <listitem>
 816           <para>Dummy library containing no functions. Previously was a runtime
 817           library for <command>g++</command></para>
 818           <indexterm zone="ch-system-glibc libg">
 819             <primary sortas="c-libg">libg</primary>
 820           </indexterm>
 821         </listitem>
 822       </varlistentry>
 823
 824       <varlistentry id="libm">
 825         <term><filename class="libraryfile">libm</filename></term>
 826         <listitem>
 827           <para>The mathematical library</para>
 828           <indexterm zone="ch-system-glibc libm">
 829             <primary sortas="c-libm">libm</primary>
 830           </indexterm>
 831         </listitem>
 832       </varlistentry>
 833
 834       <varlistentry id="libmcheck">
 835         <term><filename class="libraryfile">libmcheck</filename></term>
 836         <listitem>
 837           <para>Turns on memory allocation checking when linked to</para>
 838           <indexterm zone="ch-system-glibc libmcheck">
 839             <primary sortas="c-libmcheck">libmcheck</primary>
 840           </indexterm>
 841         </listitem>
 842       </varlistentry>
 843
 844       <varlistentry id="libmemusage">
 845         <term><filename class="libraryfile">libmemusage</filename></term>
 846         <listitem>
 847           <para>Used by <command>memusage</command> to help collect
 848           information about the memory usage of a program</para>
 849           <indexterm zone="ch-system-glibc libmemusage">
 850             <primary sortas="c-libmemusage">libmemusage</primary>
 851           </indexterm>
 852         </listitem>
 853       </varlistentry>
 854
 855       <varlistentry id="libnsl">
 856         <term><filename class="libraryfile">libnsl</filename></term>
 857         <listitem>
 858           <para>The network services library</para>
 859           <indexterm zone="ch-system-glibc libnsl">
 860             <primary sortas="c-libnsl">libnsl</primary>
 861           </indexterm>
 862         </listitem>
 863       </varlistentry>
 864
 865       <varlistentry id="libnss">
 866         <term><filename class="libraryfile">libnss</filename></term>
 867         <listitem>
 868           <para>The Name Service Switch libraries, containing functions for
 869           resolving host names, user names, group names, aliases, services,
 870           protocols, etc.</para>
 871           <indexterm zone="ch-system-glibc libnss">
 872             <primary sortas="c-libnss">libnss</primary>
 873           </indexterm>
 874         </listitem>
 875       </varlistentry>
 876
 877       <varlistentry id="libpcprofile">
 878         <term><filename class="libraryfile">libpcprofile</filename></term>
 879         <listitem>
 880           <para>Can be preloaded to PC profile an executable</para>
 881           <indexterm zone="ch-system-glibc libpcprofile">
 882             <primary sortas="c-libpcprofile">libpcprofile</primary>
 883           </indexterm>
 884         </listitem>
 885       </varlistentry>
 886
 887       <varlistentry id="libpthread">
 888         <term><filename class="libraryfile">libpthread</filename></term>
 889         <listitem>
 890           <para>The POSIX threads library</para>
 891           <indexterm zone="ch-system-glibc libpthread">
 892             <primary sortas="c-libpthread">libpthread</primary>
 893           </indexterm>
 894         </listitem>
 895       </varlistentry>
 896
 897       <varlistentry id="libresolv">
 898         <term><filename class="libraryfile">libresolv</filename></term>
 899         <listitem>
 900           <para>Contains functions for creating, sending, and interpreting
 901           packets to the Internet domain name servers</para>
 902           <indexterm zone="ch-system-glibc libresolv">
 903             <primary sortas="c-libresolv">libresolv</primary>
 904           </indexterm>
 905         </listitem>
 906       </varlistentry>
 907
 908       <varlistentry id="librt">
 909         <term><filename class="libraryfile">librt</filename></term>
 910         <listitem>
 911           <para>Contains functions providing most of the interfaces specified
 912           by the POSIX.1b Realtime Extension</para>
 913           <indexterm zone="ch-system-glibc librt">
 914             <primary sortas="c-librt">librt</primary>
 915           </indexterm>
 916         </listitem>
 917       </varlistentry>
 918
 919       <varlistentry id="libthread_db">
 920         <term><filename class="libraryfile">libthread_db</filename></term>
 921         <listitem>
 922           <para>Contains functions useful for building debuggers for
 923           multi-threaded programs</para>
 924           <indexterm zone="ch-system-glibc libthread_db">
 925             <primary sortas="c-libthread_db">libthread_db</primary>
 926           </indexterm>
 927         </listitem>
 928       </varlistentry>
 929
 930       <varlistentry id="libutil">
 931         <term><filename class="libraryfile">libutil</filename></term>
 932         <listitem>
 933           <para>Contains code for <quote>standard</quote> functions used in
 934           many different Unix utilities</para>
 935           <indexterm zone="ch-system-glibc libutil">
 936             <primary sortas="c-libutil">libutil</primary>
 937           </indexterm>
 938         </listitem>
 939       </varlistentry>
 940
 941     </variablelist>
 942
 943   </sect2>
 944
 945 </sect1>