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Glibc (2.2.5):

Glibc-linuxthreads (2.2.5):

Glibc Patch (2.2.5-2):

Contents of Glibc

Last checked against version 2.2.5.

Program Files

catchsegv, gencat, getconf, getent, glibcbug, iconv, iconvconfig, ldconfig, ldd, lddlibc4, locale, localedef, mtrace, nscd, nscd_nischeck, pcprofiledump, pt_chown, rpcgen, rpcinfo, sln, sprof, tzselect, xtrace, zdump and zic



catchsegv can be used to create a stack trace when a program terminates with a segmentation fault.


gencat generates message catalogues.


getconf displays the system configuration values for filesystem specific variables.


getent gets entries from an administrative database.


glibcbug creates a bug report about glibc and and mails it to the bug email address.


iconv performs character set conversion.


iconvconfig creates fastloading iconv module configuration file.


ldconfig configures the dynamic linker run time bindings.


ldd prints the shared libraries required by each program or shared library specified on the command line.


lddlibc4 assists ldd with object files.


locale is a Perl program which tells the compiler to enable (or disable) the use of POSIX locales for built-in operations.


localedef compiles locale specifications.


mtrace prints the multicast path from a source to a receiver (an IP trace query).


nscd is a daemon that provides a cache for the most common name service requests.


nscd_nischeck checks whether or not secure mode is necessary for NIS+ lookup.


pcprofiledump dumps information generated by PC profiling.


pt_chown sets the owner, group and access permission of the slave pseudo terminal corresponding to the master pseudo terminal passed on file descriptor `3'. This is the helper program for the `grantpt' function. It is not intended to be run directly from the command line.


rpcgen generates C code to implement the RPC protocol.


rpcinfo makes an RPC call to an RPC server.


sln symbolically links dest to source. It is statically linked, needing no dynamic linking at all. Thus sln is useful to make symbolic links to dynamic libraries if the dynamic linking system for some reason is nonfunctional.


sprof reads and displays shared object profiling data.


tzselect asks the user for information about the current location and outputs the resulting time zone description to standard output.


xtrace traces execution of program by printing the currently executed function.


zdump is the time zone dumper.


zic is the time zone compiler.

Library Files, libBrokenLocale.[a,so], libBrokenLocale_p.a,, libanl.[a,so], libanl_p.a, libbsd-compat.a, libc.[a,so], libc_nonshared.a, libc_p.a, libcrypt.[a,so], libcrypt_p.a, libdl.[a,so], libdl_p.a, libg.a, libieee.a, libm.[a,so], libm_p.a, libmcheck.a,, libnsl.a, libnsl_p.a,,,,,,,, libpthread.[a,so], libpthread_p.a, libresolv.[a,so], libresolv_p.a, librpcsvc.a, librpcsvc_p.a, librt.[a,so], librt_p.a,, libutil.[a,so] and libutil_p.a

Descriptions is the helper program for shared library executables.

libBrokenLocale, libBrokenLocale_p

Used by software, such as Mozilla, to solve broken locales.


libSegFault is a segmentation fault signal handler. It tries to catch segfaults.

libanl, libanl_p

libanl is an asynchronous name lookup library.


libbsd-compat provides the portability needed in order to run certain programs in Linux.

libc, libc_nonshared, libc_p

These files constitute the main C library. The C library is a collection of commonly used functions in programs. This way a programmer doesn't need to create his own functions for every single task. The most common things like writing a string to the screen are already present and at the disposal of the programmer.

The C library (actually almost every library) comes in two flavors: a dynamic and a static one. In short, when a program uses a static C library, the code from the C library is copied into the executable file. When a program uses a dynamic library, the executable will not contain the code from the C library, but instead a routine that loads the functions from the library at the time the program is run. This means a significant decrease in the file size of a program. The documentation that comes with the C library describes this in more detail, as it is too complicated to explain here in one or two lines.

libcrypt, libcrypt_p

libcrypt is the cryptography library.

libdl, libdl_p

libdl is the dynamic linking interface library.


libg is a runtime library for g++.


libieee is the IEEE floating point library.

libm, libm_p

libm is the mathematical library.


libmcheck contains code run at boot.


libmemusage is used by memusage to help collect information about the memory usage of a program.

libnsl, libnsl_p

libnsl is the network services library.

libnss_compat, libnss_dns, libnss_files, libnss_hesiod, libnss_nis, libnss_nisplus

The basic idea is to put the implementation of the different services offered to access the databases in separate modules. This has some advantages:

  • contributors can add new services without adding them to GNU C library,

  • the modules can be updated separately,

  • the C library image is smaller.


Code used by the kernel to track CPU time spent in functions, source code lines, and instructions.

libpthread, libpthread_p

The POSIX threads library.

libresolv, libresolv_p

Functions in this library provide for creating, sending, and interpreting packets to the Internet domain name servers.

librpcsvc, librpcsvc_p

Functions in this library provide miscellaneous RPC services.

librt, librt_p

Functions in this library provide most of the interfaces specified by the POSIX.1b Realtime Extension.


Functions is this library are useful for building debuggers for multi-threaded programs.

libutil, libutil_p

Contains code for "standard" functions used in many different Unix utilities.

Glibc Installation Dependencies

Last checked against version 2.2.5.

Bash: sh
Binutils: ar, as, ld, ranlib, readelf
Diffutils: cmp
Fileutils: chmod, cp, install, ln, mknod, mv, mkdir, rm, touch
Gcc: cc, cc1, collect2, cpp, gcc
Grep: egrep, grep
Gzip: gzip
Make: make
Gawk: gawk
Sed: sed
Sh-utils: date, expr, hostname, pwd, uname
Texinfo: install-info, makeinfo
Textutils: cat, cut, sort, tr