%general-entities; ]> Glibc-&glibc-version; Glibc <para>The Glibc package contains the main C library. This library provides the basic routines for allocating memory, searching directories, opening and closing files, reading and writing files, string handling, pattern matching, arithmetic, and so on.</para> </sect2> <sect2 role="installation"> <title>Installation of Glibc Some packages outside of CLFS suggest installing GNU libiconv in order to translate data from one encoding to another. The project's home page () says This library provides an iconv() implementation, for use on systems which don't have one, or whose implementation cannot convert from/to Unicode. Glibc provides an iconv() implementation and can convert from/to Unicode, therefore libiconv is not required on a CLFS system. The Glibc build system is self-contained and will install perfectly, even though the compiler specs file and linker are still pointing at /tools. The specs and linker cannot be adjusted before the Glibc install because the Glibc Autoconf tests would give false results and defeat the goal of achieving a clean build. The following patch fixes an issue that can cause localdef to segfault: patch -Np1 -i ../&glibc-localedef_segfault-patch; The following patch fixes an issue with iconv: patch -Np1 -i ../&glibc-iconv_fix-patch; The following sed fixes a build issue with Glibc. This will prevent nscd from trying to link to libraries that don't exist: cp -v nscd/Makefile{,.orig} sed -e "/nscd_stat.o: sysincludes = # nothing/d" nscd/Makefile.orig > \ nscd/Makefile The Glibc documentation recommends building Glibc outside of the source directory in a dedicated build directory: mkdir -v ../glibc-build cd ../glibc-build Prepare Glibc for compilation: ../glibc-&glibc-version;/configure --prefix=/usr \ --disable-profile --enable-add-ons --enable-kernel=2.6.0 \ --libexecdir=/usr/lib/glibc The meaning of the new configure option: --libexecdir=/usr/lib/glibc This changes the location of the pt_chown program from its default of /usr/libexec to /usr/lib/glibc. Compile the package: make The test suite for Glibc is considered critical. Do not skip it under any circumstance. Test the results: make -k check >glibc-check-log 2>&1 ; grep Error glibc-check-log The Glibc test suite is highly dependent on certain functions of the host system, in particular the kernel. The posix/annexc test normally fails and you should see Error 1 (ignored) in the output. Apart from this, the Glibc test suite is always expected to pass. However, in certain circumstances, some failures are unavoidable. If a test fails because of a missing program (or missing symbolic link), or a segfault, you will see an error code greater than 127 and the details will be in the log. More commonly, tests will fail with Error 2 - for these, the contents of the corresponding .out file, e.g. posix/annexc.out may be informative. Here is a list of the most common issues: The math tests, at least on i686, fail in the test-double and test-idouble tests with gcc-&gcc-version; . These two failures in the math tests appear to be harmless. The math tests may also fail on systems where the CPU is not a relatively new genuine Intel or authentic AMD. Certain optimization settings are also known to be a factor here. The gettext test sometimes fails due to host system issues. The exact reasons are not yet clear. If you have mounted the CLFS partition with the noatime option, the atime test will fail. As mentioned in , do not use the noatime option while building CLFS. When running on older and slower hardware, some tests can fail because of test timeouts being exceeded. Though it is a harmless message, the install stage of Glibc will complain about the absence of /etc/ld.so.conf. Prevent this warning with: touch /etc/ld.so.conf Install the package: make install Internationalization The locales that can make the system respond in a different language were not installed by the above command. Install them with: make localedata/install-locales To save time, an alternative to running the previous command (which generates and installs every locale listed in the glibc-&glibc-version;/localedata/SUPPORTED file) is to install only those locales that are wanted and needed. This can be achieved by using the localedef command. Information on this command is located in the INSTALL file in the Glibc source. However, there are a number of locales that are essential in order for the tests of future packages to pass, in particular, the libstdc++ tests from GCC. The following instructions, instead of the install-locales target used above, will install the minimum set of locales necessary for the tests to run successfully: mkdir -pv /usr/lib/locale localedef -i de_DE -f ISO-8859-1 de_DE localedef -i de_DE@euro -f ISO-8859-15 de_DE@euro localedef -i en_HK -f ISO-8859-1 en_HK localedef -i en_PH -f ISO-8859-1 en_PH localedef -i en_US -f ISO-8859-1 en_US localedef -i es_MX -f ISO-8859-1 es_MX localedef -i fa_IR -f UTF-8 fa_IR localedef -i fr_FR -f ISO-8859-1 fr_FR localedef -i fr_FR@euro -f ISO-8859-15 fr_FR@euro localedef -i it_IT -f ISO-8859-1 it_IT localedef -i ja_JP -f EUC-JP ja_JP Some locales installed by the make localedata/install-locales command above are not properly supported by some applications that are in the CLFS and BLFS books. Because of the various problems that arise due to application programmers making assumptions that break in such locales, CLFS should not be used in locales that utilize multibyte character sets (including UTF-8) or right-to-left writing order. Numerous unofficial and unstable patches are required to fix these problems, and it has been decided by the CLFS developers not to support such complex locales at this time. This applies to the ja_JP and fa_IR locales as well—they have been installed only for GCC and Gettext tests to pass, and the watch program (part of the Procps package) does not work properly in them. Various attempts to circumvent these restrictions are documented in internationalization-related hints. Configuring Glibc /etc/nsswitch.conf /etc/localtime The /etc/nsswitch.conf file needs to be created because, although Glibc provides defaults when this file is missing or corrupt, the Glibc defaults do not work well in a networked environment. The time zone also needs to be configured. Create a new file /etc/nsswitch.conf by running the following: cat > /etc/nsswitch.conf << "EOF" # Begin /etc/nsswitch.conf passwd: files group: files shadow: files hosts: files dns networks: files protocols: files services: files ethers: files rpc: files # End /etc/nsswitch.conf EOF To determine the local time zone, run the following script: tzselect After answering a few questions about the location, the script will output the name of the time zone (e.g., EST5EDT or Canada/Eastern). Then create the /etc/localtime file by running: cp -v --remove-destination /usr/share/zoneinfo/[xxx] \ /etc/localtime Replace [xxx] with the name of the time zone that tzselect provided (e.g., Canada/Eastern). The meaning of the cp option: --remove-destination This is needed to force removal of the already existing symbolic link. The reason for copying the file instead of using a symlink is to cover the situation where /usr is on a separate partition. This could be important when booted into single user mode. Configuring The Dynamic Loader /etc/ld.so.conf By default, the dynamic loader (/lib/ld-linux.so.2) searches through /lib and /usr/lib for dynamic libraries that are needed by programs as they are run. However, if there are libraries in directories other than /lib and /usr/lib, these need to be added to the /etc/ld.so.conf file in order for the dynamic loader to find them. Two directories that are commonly known to contain additional libraries are /usr/local/lib and /opt/lib, so add those directories to the dynamic loader's search path. Create a new file /etc/ld.so.conf by running the following: cat > /etc/ld.so.conf << "EOF" # Begin /etc/ld.so.conf /usr/local/lib /opt/lib # End /etc/ld.so.conf EOF Contents of Glibc Installed programs Installed libraries catchsegv, gencat, getconf, getent, iconv, iconvconfig, ldconfig, ldd, lddlibc4, locale, localedef, mtrace, nscd, pcprofiledump, pt_chown, rpcgen, rpcinfo, sln, sprof, tzselect, xtrace, zdump, and zic ld.so, libBrokenLocale.[a,so], libSegFault.so, libanl.[a,so], libbsd-compat.a, libc.[a,so], libcrypt.[a,so], libdl.[a,so], libg.a, libieee.a, libm.[a,so], libmcheck.a, libmemusage.so, libnsl.a, libnss_compat.so, libnss_dns.so, libnss_files.so, libnss_hesiod.so, libnss_nis.so, libnss_nisplus.so, libpcprofile.so, libpthread.[a,so], libresolv.[a,so], librpcsvc.a, librt.[a,so], libthread_db.so, and libutil.[a,so] Short Descriptions catchsegv Can be used to create a stack trace when a program terminates with a segmentation fault catchsegv gencat Generates message catalogues gencat getconf Displays the system configuration values for file system specific variables getconf getent Gets entries from an administrative database getent iconv Performs character set conversion iconv iconvconfig Creates fastloading iconv module configuration files iconvconfig ldconfig Configures the dynamic linker runtime bindings ldconfig ldd Reports which shared libraries are required by each given program or shared library ldd lddlibc4 Assists ldd with object files lddlibc4 locale Tells the compiler to enable or disable the use of POSIX locales for built-in operations locale localedef Compiles locale specifications localedef mtrace Reads and interprets a memory trace file and displays a summary in human-readable format mtrace nscd A daemon that provides a cache for the most common name service requests nscd pcprofiledump Dumps information generated by PC profiling pcprofiledump pt_chown A helper program for grantpt to set the owner, group and access permissions of a slave pseudo terminal pt_chown rpcgen Generates C code to implement the Remote Procecure Call (RPC) protocol rpcgen rpcinfo Makes an RPC call to an RPC server rpcinfo sln A statically linked program that creates symbolic links sln sprof Reads and displays shared object profiling data sprof tzselect Asks the user about the location of the system and reports the corresponding time zone description tzselect xtrace Traces the execution of a program by printing the currently executed function xtrace zdump The time zone dumper zdump zic The time zone compiler zic ld.so The helper program for shared library executables ld.so libBrokenLocale Used by programs, such as Mozilla, to solve broken locales libBrokenLocale libSegFault The segmentation fault signal handler libSegFault libanl An asynchronous name lookup library libanl libbsd-compat Provides the portability needed in order to run certain Berkey Software Distribution (BSD) programs under Linux libbsd-compat libc The main C library libc libcrypt The cryptography library libcrypt libdl The dynamic linking interface library libdl libg A runtime library for g++ libg libieee The Institute of Electrical and Electronic Engineers (IEEE) floating point library libieee libm The mathematical library libm libmcheck Contains code run at boot libmcheck libmemusage Used by memusage (included in Glibc, but not built in a base CLFS system as it has additional dependencies) to help collect information about the memory usage of a program libmemusage libnsl The network services library libnsl libnss The Name Service Switch libraries, containing functions for resolving host names, user names, group names, aliases, services, protocols, etc. libnss libpcprofile Contains profiling functions used to track the amount of CPU time spent in specific source code lines libpcprofile libpthread The POSIX threads library libpthread libresolv Contains functions for creating, sending, and interpreting packets to the Internet domain name servers libresolv librpcsvc Contains functions providing miscellaneous RPC services librpcsvc librt Contains functions providing most of the interfaces specified by the POSIX.1b Realtime Extension librt libthread_db Contains functions useful for building debuggers for multi-threaded programs libthread_db libutil Contains code for standard functions used in many different Unix utilities libutil