[Techtalk] Linux file system versus dos/win model

Anne Wainwright anotheranne at fables.co.za
Wed Jul 30 21:01:52 UTC 2008

Hi, see below.

Thanks for your input especially the use of the "/" character. 

On Wed, 30 Jul 2008 09:41:28 -0400
Stephanie wrote:

|> Hello, 
|> I didn't see it mentioned anywhere within the discussion and thought it might be fun side but related tidbit for the curious.  A while ago I had questions surrounding differences between Linux_FS and DOS_FS.  Especially the whole thing with why the use of a forward slashes in LInux and back slashes in DOS/Windows within file path naming conventions.  Initially I thought I would find that this was MS just trying to assert evil and inconvenience to Linux users but it turns out it was much more benign than that :)....
|> Basically came across info that explained that DOS/Windows ended up using back slashes in this way because way back when (pre Windows GUI) they implemented the use of forward slashes as the syntax for specifying command line options.  Similar to the use of the short dash, "-" used in Linux for specifying command line options. 
|> E.g. The following DOS command, "ipconfig" will give a basic listing of your computer's LAN info (DNS suffix, IP Address, Subnet, Default Gateway).  However a much more in depth detail is provided by using the "all" option as shown below.   
|> C:\ Documents and Setting\stephanie>  ipconifg /all
|>               <returns detailed LAN information>  
|> Is it the whole truth of the matter? Not 100% sure, but remember at the time it seemed like a pretty credible explanation.  Unfortunately I don't have a source as it was a while ago, but it probably wouldn't be hard to find.

I did a little bit of research this evening, can't think why but I checked out Wikipedia on CP/M which led me to the following link. 


from which I quote

So, of all the programs supplied with CP/M, none uses the "/" character as an option leadin. Then where did the slash come from?

A hasty search of the SIG/M library (archived on the CP/M CDROM) suggests that one early program that used "/" was DCHBYE (a program that allows a CP/M program to be remotely controlled by a modem). The original program was written by Dave Jaffe in January 1979; DCHBYE dates from 17 October 1980. The convention seems to be confined to BYE until SUPERSUB (18 February 1981) is released; and by the time we reach ZCPR (1982-1983), it's used in a lot of programs.

It may be that the convention did originate with BYE, but there's another possibility. At the time MS-DOS was written, Microsoft sold various language compilers (BASIC, FORTRAN, M80, etc.). These tools were influential; some accounts say that BDOS call 28h was added specifically to support Microsoft FORTRAN, and the .REL file format they use became the standard format for CP/M assemblers and linkers. And the option character used by these programs is... "/".

So you were on the ball!


|> Enjoy!
|> :) Stephanie

so much to do, so little time :(

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