Here is a direct reference from the Wikipedia article I referenced in my prior post ...
In 1973, Unix was rewritten in the C programming language<http://en.wikipedia.org/wiki/C_%28programming_language%29>, contrary to the general notion at the time "that something as complex as an operating system, which must deal with time-critical events, had to be written exclusively in assembly language".[4]<http://en.wikipedia.org/wiki/UNIX#cite_note-Stallings-3>The migration from assembly language <http://en.wikipedia.org/wiki/Assembly_Language> to the higher-level language <http://en.wikipedia.org/wiki/High-level_programming_language> C resulted in much more portable<http://en.wikipedia.org/wiki/Software_quality#Portability>software, requiring only a relatively small amount of machine-dependent code to be replaced when porting Unix to other computing platforms<http://en.wikipedia.org/wiki/Platform_%28computing%29> . Prince On Fri, Dec 5, 2008 at 7:57 PM, Prince Riley <[EMAIL PROTECTED]> wrote: > Hello > > I don't mean to start a culture war here, but I think there is a bit of > overstatement in this post that 'C' is somehow a better language for writing > an OS in than say Pascal or OP or anything else. > > In point of fact, the only 'best' language for any processor is its own > machine code which is always binary. > And the first operating system software written was done so in the assembly > language which is written to use mnemoics > that when 'assembled' convert directly into the binary machine language on > a one to one basis. > > Now EVERY compiled language, including C, must be processed from its > syntactical representation into assembly language or machine code. In fact, > if you download the GCC complier source code and read it, you'll see almost > immediately that it actually a 'language' front-end connected to a > 'assembler machine code' back end. > > When the 'C' language was designed at AT&T it used 'assembler' like > constructs and syntax because it's author wanted > to stop writing programs in a language called BCPL.. > > So aside from a 'historical accident' that the first AT&T OS ..UNIX.. was > being written at the same time C was being developed, there is no other > reason for any program, including an OS, to be written in C. To suggest that > C is better is rather like suggesting that Spanish is a better language than > English for writing a novel. > > That said, if someone wished to write a modern OS in FP, which has nearly > every programming construct that 'C' has (ints, doubles, floats, bytes, and > bits) and you were willing to put in the time to fine tune and modify the FP > compiler, you could produce a OS in FP that would be every bit as effective > and perform as well or better as one written in C. And as far as the > processor running the OS couldn't tell what language the OS was written in. > > > If anyone wants to convince themselves on this its simple, you'll find > Ritchie (the creator of the C language) explained these points in the > preface to his first book on C. There is also a brief mention of this in the > Wikipedia article on the UNIX operating system. (see the article footnotes) > > Prince > > > On Fri, Dec 5, 2008 at 6:59 PM, Guillermo Martínez Jiménez < > [EMAIL PROTECTED]> wrote: > >> > Are you sure? >> >> Yes, I am. >> >> > doesn't older MacOS's versions where written in Object Pascal? >> >> Yes, it does, but as I said I think it wasn't the better options. >> >> > I think the problem here (again) is not the language, it's the critical >> mass of users of the language. Using C for Linux was a good bet, not because >> the language is good (Pascal is way better for me), but because C has a >> wider user base who can fix/add features. >> >> I disagree. C is better for write operating systems *by definition*: >> C was created to write UNIX, Pascal was created to learn good >> programming techniques. C is low/mid-level language, Pascal is >> high-level (and Object Pascal is even higher): OS are the lowest >> software level. >> >> I'm not saying it's impossible: here you have MacOS and Toro. I'm >> just saying that _I think_ it isn't the best option. Of course a >> better option is to write the kernel in C and Assembler and the >> utilities in Pascal and Object Pascal. >> >> Guillermo "Ñuño" Martínez >> _______________________________________________ >> fpc-pascal maillist - fpc-pascal@lists.freepascal.org >> http://lists.freepascal.org/mailman/listinfo/fpc-pascal >> > >
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