[Info-vax] wrong file format

[Dirk Munk]

Arne Vajhøj wrote:
> On 1/1/2021 11:52 AM, Dirk Munk wrote:
>> Bill Gunshannon wrote:
>>> On 1/1/21 10:46 AM, Dirk Munk wrote:
>>>> Bill Gunshannon wrote:
>>>>> On 12/31/20 3:58 PM, Dirk Munk wrote:
>>>>>> like indexed files. What will that application do with those 
>>>>>> files? RMS will tell you the structure of the file, you don't have 
>>>>>> to guess it.
>>>>>
>>>>> I use GnuCOBOL.  sequential files show up as "ASCII text: as does the
>>>>> COBOL Source File.  Indexed report as "Berkeley DB" as that was the
>>>>> option I chose for indexed files when I built GnuCOBOL.  Other COBOL
>>>>> compiler (like MicroFocus) may differ. Of course, the executable shows
>>>>> up as "ELF 64-bit LSB shared object".  If I wanted to put in the
>>>>> effort I could probably get it to identify the source as COBOL source
>>>>> but I  see no reason to bother.
>>>>>
>>>>
>>>> Cobol source files are always text files of course. But again, with 
>>>> VMS all the file types are offered by RMS, and can be used by any 
>>>> language or even DCL.
>>>
>>> And, as I stated above the exact same is true of Unix and OS-9 and
>>> RT-11 and Windows and probably every other OS.
>>
>> No, Unix does not offer indexed sequential files etc. as standardized 
>> part of the operating system. They can be added as part of a compiler, 
>> like Cobol, but then those files can only be used by applications 
>> written with that compiler, unless the same filesystem is used by 
>> another compiler.
> 
> File system does not matter - from the file system perspective
> then ISAM files are also just a stream of bytes on *nix.
> 
> But yes different compilers use different ISAM libraries. So
> to access files using a different compiler, then either that
> compiler must use the same library *or* the program must
> use the library API explicit.

That is what I mean. You can only use those files by using the ISAM 
library, and the ISAM library is not a part of Unix. It is running on 
Unix, but not part of it, and you have the choice of several ISAM libraries.

With VMS the standard ISAM library is RMS.

> 
>> It seems that Windows does have more file types as part of the OS, but 
>> that feature is very well hidden.
> 
> What are you referring to?
> 

It seems that Windows has a standard ISAM library, and the Windows 
operating system is even using it.