View source for UClibc

{{Short description|Implementation of C standard library for embedded systems based on Linux}}
__NOTOC__{{Lowercase title}}
{{Infobox software
| name                   = uClibc
| title                  = uClibc
| logo                   = <!-- [[File: ]] -->
| logo caption           = 
| screenshot             = <!-- [[File: ]] -->
| caption                = 
| collapsible            = 
| author                 = 
| developer              = Erik Andersen
| released               = {{Start date and age|2000|02|13}}
| discontinued           = yes
| programming language   = [[C (programming language)|C]]
| operating system       = [[Linux]]
| platform               = [[Embedded Linux]]
| size                   = 
| language               = 
| genre                  = {{ubl|[[Runtime library]]|[[C standard library]]}}
| license                = [[GNU Lesser General Public License|LGPLv2.1]]<ref>{{cite web |url=http://www.uclibc.org/FAQ.html#licensing |title=uClibc FAQ: Licensing |work=uclibc.org |access-date=11 July 2015}}</ref>
| website                = {{URL|https://www.uclibc.org/}}
| repo                   = {{URL|https://git.uclibc.org/uClibc/}}
}}
{{Infobox software
| name                   = uClibc-ng
| title                  = uClibc-ng
| latest release version = 1.0.52
| latest release date    = {{Start date and age|2025|04|06}}
| website                = {{URL|https://www.uclibc-ng.org/}}
| repo                   = {{URL|https://cgit.uclibc-ng.org/cgi/cgit/uclibc-ng.git/}}
}}

In [[computing]], '''uClibc''' (sometimes written μClibc) is a small [[C standard library]] intended for [[Linux kernel]]-based operating systems for [[Linux for embedded systems|embedded systems]] and [[Linux for mobile devices|mobile devices]]. uClibc was written to support [[μClinux]], a version of Linux not requiring a [[memory management unit]] and thus suited for [[microcontroller]]s (uCs; the "u" is a [[Latin script]] typographical [[approximation]] - not a proper [[romanization]], which would be letter "m" - of [[μ]] for "micro").<ref>[http://www.uclibc.org/FAQ.html#naming uClibc naming] Accessed on February 10, 2008.</ref>

Development on uClibc started around 1999.<ref>{{cite web |url=http://www.uclibc.org/copyright.txt |title=μClibc Copyright |format=TXT |access-date=February 23, 2024}}</ref> uClibc was mostly written from scratch,<ref>{{cite web | url = http://www.uclibc.org/FAQ.html#history | title = History | work = uClibc FAQ | access-date = 2007-06-19 }}</ref> but has incorporated code from glibc and other projects.<ref>{{cite web | url = http://www.uclibc.org/downloads/Changelog | title = uClibc Changelog | access-date = 2007-06-19 | quote = pthreads support (derived from glibc 2.1.3's linuxthreads library) [...] Merged in the random number support (rand, srand, etc) from glibc. |archive-url = https://web.archive.org/web/20070609171609/http://www.uclibc.org/downloads/Changelog <!-- Bot retrieved archive --> |archive-date = 2007-06-09}}</ref>  The project lead is Erik Andersen, and the other main contributor is Manuel Novoa III. Licensed under the [[GNU Lesser General Public License]], uClibc is [[free and open-source software]].

[[File:Linux kernel System Call Interface and uClibc.svg|thumb|300px|right|uClibc is a wrapper around the [[system call]]s of the [[Linux kernel]] and [[μClinux]].]]

uClibc is much smaller than the [[GNU C Library|glibc]], the C library normally used with Linux distributions. While glibc is intended to fully support all relevant C standards across a wide range of hardware and kernel platforms, uClibc is specifically focused on embedded Linux systems. Features can be enabled or disabled according to space requirements.

uClibc runs on standard and [[memory management unit|MMU]]-less Linux systems. It supports [[Intel 386|i386]], [[x86-64]], [[ARM architecture|ARM]] (big/little endian), [[AVR32|Atmel AVR32]], [[Blackfin|Analog Devices Blackfin]], [[H8 Family|Renesas/Hitachi H8 (h8300)]], [[m68k|Motorola m68k]], [[MIPS architecture|MIPS]] (big/little endian), [[PowerPC|IBM PowerPC]], [[SuperH]] (big/little endian), [[SPARC|Sun SPARC]], and [[v850|Renesas/NEC v850]] processors.

'''uClibc-ng'''<ref>{{cite web|url=https://www.uclibc-ng.org/|title=uClibc-ng|work=uclibc-ng.org|access-date=11 July 2015}}</ref> is a [[fork (software development)|fork]] of uClibc announced on the [[OpenWRT]] mailing list in July 2014 after more than two years had passed without a uClibc release, citing a lack of any communication from the maintainer.<ref>{{cite mailing list|mailing-list=openwrt-devel|url=https://lists.openwrt.org/pipermail/openwrt-devel/2014-July/026922.html|title=uClibc-ng|date=20 July 2014|last=Brodkorb|first=Waldemar|access-date=21 June 2017|archive-date=21 June 2017|archive-url=https://web.archive.org/web/20170621004032/https://lists.openwrt.org/pipermail/openwrt-devel/2014-July/026922.html}}</ref><ref>{{cite mailing list|mailing-list=uclibc|title=uClibc-ng |url=http://lists.uclibc.org/pipermail/uclibc/2014-July/048400.html |date=21 July 2014 |last=Petazzoni|first=Thomas |archive-url=https://web.archive.org/web/20170621001946/http://lists.uclibc.org/pipermail/uclibc/2014-July/048400.html |archive-date=2017-06-21}}</ref><ref>{{cite mailing list|mailing-list=openwrt-devel|url=https://lists.openwrt.org/pipermail/openwrt-devel/2014-July/026953.html|title=uClibc-ng|date=21 July 2014|last=Brodkorb|first=Waldemar|access-date=21 June 2017|archive-date=21 June 2017|archive-url=https://web.archive.org/web/20170621004048/https://lists.openwrt.org/pipermail/openwrt-devel/2014-July/026953.html}}</ref> At present, the original project's author no longer publishes updates, but refers to the still actively developed fork uClibc-ng for current releases.<ref>{{cite web |url=https://www.uclibc.org/news.html |title=uClibc - Latest News|access-date=2019-01-09}}</ref>

==See also==
{{Portal|Free and open-source software}}

{{Div col|colwidth=20em}}
* [[Alpine Linux]]
* [[Buildroot]]
* [[busybox]]
* [[Contiki]]
* [[OpenWrt]]
* [[musl]]
* [[Linux for embedded systems]]
* [[Linux for mobile devices]]
{{div col end}}

==References==
{{Reflist|30em}}

==Further reading==
* {{cite book |author=Karim Yaghmour |author2=Jon Masters |author3=Gilad Ben-Yossef |author4=Philippe Gerum |title=Building Embedded Linux Systems|edition=2|publisher=O'Reilly Media|year=2008|isbn=978-0-596-52968-0|pages=115–127}}
* {{cite book |author=von Hagen, William L. |title=The Definitive Guide to GCC, Second Edition |publisher=APress |location=Berkeley, CA |year=2006 |pages=290–297 |isbn=1-59059-585-8 }}

==External links==
* [https://cxx.uclibc.org uClibc++ website]

{{C programming language|state=collapsed}}
{{Embedded systems}}

{{DEFAULTSORT:Uclibc}}
[[Category:2000 software]]
[[Category:C standard library]]
[[Category:Embedded Linux]]
[[Category:Free computer libraries]]
[[Category:Free software programmed in C]]
[[Category:Interfaces of the Linux kernel]]
[[Category:Linux APIs]]
[[Category:Software using the GNU Lesser General Public License]]