Product Code Database
The GNU C Library, commonly known as glibc, is the GNU Project implementation of the C standard library. It provides a wrapper around the system calls of the Linux kernel and other kernels for application use. Despite its name, it now also directly supports C++ (and, indirectly, other programming languages). It was started in the 1980s by the Free Software Foundation (FSF) for the GNU operating system.
glibc is free software released under the GNU Lesser General Public License. The GNU C Library project provides the core libraries for the GNU system, as well as many systems that use Linux kernel as the kernel. These libraries provide critical including ISO C11, POSIX.1-2008, BSD, OS-specific APIs and more. These APIs include such foundational facilities as open, read, write, malloc, printf, getaddrinfo, dynamic loading, pthreads, crypt, login, exit and more.
| Minimum for Linux Standard Base (LSB) 3.0 |
| Minimum for LSB 4.0, initial inotify support |
| Full inotify support. RHEL5 end of support was |
| Minimum for LSB 5.0. Initial psiginfo support. |
| SLES11 reached end of long-term support in March 2022. |
| x32 ABI support, ISO C11 compliance, SystemTap |
| 64-bit ARM support |
| Improved C++11 support. Support for Intel TSX lock elision. Support for the Xilinx MicroBlaze and IBM POWER8 microarchitectures. |
| SystemTap probes for malloc. GNU Indirect Function (IFUNC) support for ppc32 and ppc64. New feature test macro _DEFAULT_SOURCE to replace _SVID_SOURCE and _BSD_SOURCE. Preliminary safety documentation for all functions in the manual. ABI change in ucontext and jmp_buf for s390/s390x. |
| Support for file description locks |
| New semaphore implementation |
| Support to enable Google Native Client (NaCl), that originally ran on x86, running on ARMv7-A, Unicode 7.0 |
| Unicode 8.0 |
| Some deprecated features have been removed |
| The getentropy and getrandom functions, and the <sys/random.h> header file have been added. |
| Improved performance (per-thread cache for malloc), Unicode 10 support |
| Performance optimizations. RISC-V support. |
| statx, renameat2, Unicode 11.0.0 |
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| Unicode 12.1.0, the dynamic linker accepts the --preload argument to preload shared objects, the gettid function has been added on Linux, Minguo (Republic of China) calendar support, new Japanese era added to ja_JP locale, memory allocation functions fail with total object size larger than PTRDIFF_MAX; fixed |
| Initial C23 standard support |
| Unicode 13.0, 'access' attribute for better warnings in GCC 10, i.e. to "help detect buffer overflows and other out-of-bounds accesses" |
| HWCAPS |
| libpthread, libdl, libutil, libanl has been integrated into libc. |
| Unicode 14.0, C.UTF-8 locale, restartable sequences. Removed Intel MPX support. |
| The strlcpy and strlcat functions added. libmvec support for ARM64. |
| The stdbit.h header has been added from ISO C2X. Support for shadow stacks on x86_64, new security features, and the removal of libcrypt. |
| Partial support for the ISO C23 standard, a new tunable for the testing of programs, improved 64-bit ARM vector support. |
| Add , , functions. |
| New math functions, support for arbitrary baud rates in the termios.h interface, SFrame-based stack tracing. |
The glibc project was initially written mostly by Roland McGrath, working for the Free Software Foundation (FSF) in the summer of 1987 as a teenager. In February 1988, FSF described glibc as having nearly completed the functionality required by ANSI C. By 1992, it had the ANSI C-1989 and POSIX.1-1990 functions implemented and work was under way on POSIX.2. In September 1995 Ulrich Drepper made his first contribution to the glibc and by 1997 most commits were made by him. Drepper held the maintainership position for many years and until 2012 accumulated 63% of all commits to the project.
In May 2009, glibc was migrated to a Git repository.
In 2010, a licensing issue was resolved which was caused by the Sun RPC implementation in glibc that was not GPL compatible. It was fixed by re-licensing the Sun RPC components under the BSD licenses.
In 2014, glibc suffered from an ABI breakage bug on s390.
In July 2017, 30 years after he started glibc, Roland McGrath announced his departure, "declaring myself maintainer emeritus and withdrawing from direct involvement in the project. These past several months, if not the last few years, have proven that you don't need me anymore".
In 2018, maintainer Raymond Nicholson removed a joke about abortion from the glibc source code. It was restored later by Alexandre Oliva after Richard Stallman demanded to have it returned.
In 2021, the copyright assignment requirement to the Free Software Foundation was removed from the project.
In 2009, Debian and a number of derivatives switched from glibc to the variant eglibc. Eglibc was supported by a consortium consisting of Freescale, MIPS, MontaVista and Wind River. It contained changes that made it more suitable for Embedded system and had added support for architectures that were not supported by glibc, such as the PowerPC e500. The code of eglibc was merged back into glibc at version 2.20. Since 2014, eglibc is discontinued. The Yocto Project and Debian also moved back to glibc since the release of Debian Jessie.
In March 2012, the steering committee voted to disband itself and remove Drepper in favor of a community-driven development process, with Ryan Arnold, Maxim Kuvyrkov, Joseph Myers, Carlos O'Donell, and Alexandre Oliva holding the responsibility of GNU maintainership (but no extra decision-making power).
In addition, glibc also provides extensions that have been deemed useful or necessary while developing GNU.
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