Informasi Sains    
   
Daftar Isi ☛
(Sebelumnya) GNU build systemGNU cflow (Berikutnya)

GNU C Library

GNU C Library
Heckert GNU white.svg
Original author(s)Roland McGrath
Developer(s)GNU Project
Initial release1987 (1987)[1]
Stable release2.17 (December 25, 2012; 2 months ago (2012-12-25)[2]) [±] [±]
Development statusActive
Operating systemUnix-like
TypeRuntime library
LicenseGNU Lesser General Public License
Websitewww.gnu.org/software/libc/

The GNU C Library, commonly known as glibc, is the GNU Project's implementation of the C standard library. Originally written by the Free Software Foundation (FSF) for the GNU operating system, the library's development had been overseen by a committee since 2001,[3] with Ulrich Drepper[4] as the lead contributor and maintainer. In March 2012, the steering committee voted to disband itself, in favor of a community-driven development process, with Ryan Arnold, Maxim Kuvyrkov, Joseph Myers, Carlos O'Donell, and Alexandre Oliva as non-decision making project stewards.[5][6]

Released under the GNU Lesser General Public License, glibc is free software.

Contents

History

glibc was initially written mostly by Roland McGrath, working for the Free Software Foundation (FSF) in the 1980s.

In February 1988, FSF described glibc as having nearly completed the functionality required by ANSI C.[7] By 1992, it had the ANSI C-1989 and POSIX.1-1990 functions implemented and work was under way on POSIX.2.[8]

A temporary fork

In the early 1990s, the developers of the Linux kernel forked glibc. Their fork, called "Linux libc", was maintained separately for years and released versions 2 through 5.

When FSF released glibc 2.0 in January 1997, it had much more complete POSIX standards compliance, better internationalisation and multilingual function, IPv6 capability, 64-bit data access, facilities for multithreaded applications, future version compatibility, and the code was more portable.[9] At this point, the Linux kernel developers discontinued their fork and returned to using FSF's glibc.[10]

The last used version of Linux libc used the internal name (soname) libc.so.5. Following on from this, glibc 2.x on Linux uses the soname libc.so.6[11] (Alpha and IA64 architectures now use libc.so.6.1, instead). The soname is often abbreviated as libc6 (for example in the package name in Debian) following the normal conventions for libraries.

According to Richard Stallman, the changes that had been made in Linux libc could not be merged back into glibc because the authorship status of that code was unclear and the GNU project is quite strict about recording copyright and authors.[12]

Version history

VersionDateNotes
0.1 – 0.6Oct 1991 – February 1992 
1.0February 1992 
1.01 – 1.09.3March 1992 – December 1994 
1.90 – 1.102May 1996 – January 1997 
2.0January 1997 
2.0.1January 1997 
2.0.2February 1997 
2.0.91December 1997 
2.0.95July 1998 
2.1February 1999 
2.1.1March 1999 
2.2November 2000 
2.2.1January 2001 
2.2.2February 2001 
2.2.3March 2001 
2.2.4July 2001 
2.3October 2002 
2.3.1October 2002 
2.3.2February 2003Debian 3.1 (Sarge)
2.3.3December 2003 
2.3.4December 2004Standard for LSB 3.0, Used in RHEL 4 (Update 5)
2.3.5April 2005Used in SLES 9
2.3.6November 2005Debian 4.0 (Etch)
2.4March 2006Standard for LSB 4.0, Used in SLES 10
2.5September 2006Used in RHEL 5
2.6May 2007 
2.7October 2007Debian 5 (Lenny), Ubuntu 8.04
2.8April 2008 
2.9November 2008 
2.10May 2009 
2.11October 2009SLES 11, Ubuntu 10.04, eglibc used in Debian 6 (Squeeze)
2.12May 2010Used in RHEL 6
2.13January 2011eglibc 2.13 used in Debian 7 (Wheezy)
2.14June 2011 
2.15March 2012Used in Ubuntu 12.04
2.16June 2012x32 ABI support, ISO C11 compliance, SystemTap
2.17December 201264-bit ARM support

Supported hardware and kernels

Glibc is used in systems that run many different kernels and different hardware architectures. Its most common use is in systems using the Linux kernel on x86 hardware, however, officially supported hardware includes: x86, Motorola 680x0, DEC Alpha, PowerPC, ETRAX CRIS, s390, and SPARC. It officially supports the Hurd and Linux kernels. Additionally, there are heavily patched versions that run on the kernels of FreeBSD and NetBSD (from which Debian GNU/kFreeBSD and Debian GNU/NetBSD systems are built, respectively), as well as the kernel of OpenSolaris.[13] It is also used (in an edited form) and named libroot.so in BeOS and Haiku.

Functionality

glibc provides the functionality required by the Single UNIX Specification, POSIX (1c, 1d, and 1j) and some of the functionality required by ISO C99, Berkeley Unix (BSD) interfaces, the System V Interface Definition (SVID) and the X/Open Portability Guide (XPG), Issue 4.2, with all extensions common to XSI (X/Open System Interface) compliant systems along with all X/Open UNIX extensions.

In addition, glibc also provides extensions that have been deemed useful or necessary while developing GNU.

Use in small devices

glibc has been criticized as being "bloated" and slower than other libraries in the past, e.g. by Linus Torvalds[14] and embedded Linux programmers. For this reason, several alternative C standard libraries have been created which emphasize a smaller footprint. Among them are Bionic (based mostly on libc from BSD and used in Android[15]), dietlibc, uClibc, Newlib, Klibc, and EGLIBC (used in Debian, Ubuntu and Ark Linux).[16]

However, many small-device projects use GNU libc over the smaller alternatives because of its application support, standards compliance, and completeness. Examples include Openmoko[17] and Familiar Linux for iPaq handhelds (when using the GPE display software).[18]

See also

Portal iconFree software portal

References

  1. ^ A turning point for GNU libc, By Jonathan Corbet, March 28, 2012, LWN.net
  2. ^ Miller, David (2012-12-25). "The GNU C Library version 2.17 is now available.". info-gnu. http://lists.gnu.org/archive/html/inf o-gnu/2012-12/msg00016.html. Retrieved 2012-12-27.
  3. ^ "glibc homepage". http://www.gnu.org/software/libc/. "In 2001 The GNU C Library Steering Committee ..., was formed and currently consists of Mark Brown, Paul Eggert, Andreas Jaeger, Jakub Jelinek, Roland McGrath and Andreas Schwab."
  4. ^ "Ulrich Drepper". LinkedIn. http://www.linkedin.com/in/ulrichdrep per. Retrieved 2012-06-13.
  5. ^ Roland McGrath (2012-03-26). "glibc steering committee dissolving". Sourceware.org. http://sourceware.org/ml/libc-alpha/2 012-03/msg01038.html. Retrieved 2012-06-13.
  6. ^ Joseph S. Myers (2012-03-26). "GNU C Library development and maintainers". Sourceware.org. http://sourceware.org/ml/libc-alpha/2 012-03/msg01040.html. Retrieved 2012-06-13.
  7. ^ "http://www.gnu.org/bulletins/bull4.h tml". http://www.gnu.org/bulletins/bull4.ht ml. "Most libraries are done. Roland McGrath [...] has a nearly complete set of ANSI C library functions. We hope they will be ready some time this spring."
  8. ^ "GNU's Bulletin, vol. 1 no. 12". http://www.gnu.org/bulletins/bull12.h tml. "It now contains all of the ANSI C-1989 and POSIX.1-1990 functions, and work is in progress on POSIX.2 and Unix functions (BSD and System V)"
  9. ^ Elliot Lee (2001). "A Technical Perbandingan -- glibc 2.x With Legacy System Libraries". Archived from the original on 11 April 2004. http://web.archive.org/web/2004041119 1201/http://people.redhat.com/~sopwit h/old/glibc-vs-libc5.html.
  10. ^ "Forking: it could even happen to you". http://www.linux.com/archive/feature/ 3874. "the split between GNU LIBC and the Linux LIBC -- it went on for years while Linux stabilized, and then the forks re-merged into one project"
  11. ^ "Fear of Forking essay, see "6. glibc --> Linux libc --> glibc"". http://linuxmafia.com/faq/Licensing_a nd_Law/forking.html.
  12. ^ "Fear of Forking, footnote on Stallman's merge comments". http://linuxmafia.com/faq/Licensing_a nd_Law/forking.html#foot25.
  13. ^ Bartley, David; Michael Spang. "GNU/kOpenSolaris (GNU libc/base + OpenSolaris kernel)". http://csclub.uwaterloo.ca/~dtbartle/ opensolaris/. Retrieved 2008-12-16.
  14. ^ Linus Torvalds: Posting to the glibc mailing list, 9 January 2002 19:02:37
  15. ^ Bionic libc README
  16. ^ EGLIBC
  17. ^ "OpenMoko components". http://wiki.openmoko.org/wiki/OpenMok o. "We will use glibc (not uClibC) ... The alternatives may save more space and be more optimized, but are more likely to give us integration headaches"
  18. ^ "Re: [Familiar] Which glibc for Familiar 0.8.4  ?". http://marc.info/?l=familiar&m=11 8666899424374&w=2. "Question: which version of the GLIBC was used to build the Familiar 0.8.4 ? Answer: 2.3.3"

External links

(Sebelumnya) GNU build systemGNU cflow (Berikutnya)