B (programming language): Difference between revisions

Revision as of 00:35, 31 March 2023

Revision as of 22:33, 24 July 2023

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In Thompson's words: "B and the old old C were very very similar languages except for all the types [in C]".<ref name="ken"/>

Early implementations were for the DEC [[PDP-7]] and [[PDP-11]] minicomputers using early [[Unix]], and [[Honeywell]] {{nowrap|[[GE-600 series|GE 645]]}}<ref name="Evolution">{{cite journal |first=Dennis M. |last=Ritchie |title=The Evolution of the Unix Time-sharing System |url=https://www.bell-labs.com/usr/dmr/www/hist.html |archive-url=https://web.archive.org/web/20150611114353/https://www.bell-labs.com/usr/dmr/www/hist.html |archive-date=11 June 2015 |journal=AT&T Bell Laboratories Technical Journal |volume=63 |number=6 Part 2 |year=1984 |pages=1577–1593|doi=10.1002/j.1538-7305.1984.tb00054.x }}</ref> 36-bit mainframes running the operating system [[General Comprehensive Operating System|GCOS]]. The earliest PDP-7 implementations compiled to [[threaded code]], and Ritchie wrote a compiler using [[TMG (language)|TMG]] which produced machine code.<ref>{{cite web |url=http://www.multicians.org/tmg.html |title=TMG |publisher=multicians.org}}</ref><ref>{{cite web |url=https://www.bell-labs.com/usr/dmr/www/chist.html |archive-url=https://web.archive.org/web/20150611114355/https://www.bell-labs.com/usr/dmr/www/chist.html |archive-date=11 June 2015 |title=The Development of the C Language |first=Dennis M. |last=Ritchie |author-link=Dennis Ritchie |publisher=Bell Labs/Lucent Technologies}}</ref><ref name="reader">{{cite techreporttech report |first1=M. D. |last1=McIlroy |author-link1=Douglas McIlroy |year=1987 |url=http://www.cs.dartmouth.edu/~doug/reader.pdf |archive-url=https://ghostarchive.org/archive/20221009/http://www.cs.dartmouth.edu/~doug/reader.pdf |archive-date=2022-10-09 |url-status=live |title=A Research Unix reader: annotated excerpts from the Programmer's Manual, 1971–1986 |series=CSTR |number=139 |institution=Bell Labs}}</ref> In 1970 a PDP-11 was acquired and threaded code was used for the port; an assembler, {{samp|[[dc (Unix)|dc]]}}, and the B language itself were written in B to [[Bootstrapping|bootstrap]] the computer. An early version of [[yacc]] was produced with this PDP-11 configuration. Ritchie took over maintenance during this period.<ref name=chist />{{r|reader}}

The typeless nature of B made sense on the Honeywell, PDP-7 and many older computers, but was a problem on the PDP-11 because it was difficult to elegantly access the character data type that the PDP-11 and most modern computers fully support. Starting in 1971 Ritchie made changes to the language while converting its compiler to produce machine code, most notably adding data typing for variables. During 1971 and 1972 B evolved into "New B" (NB) and then C.<ref name=chist />