Why use U* over VMS

larry hughes hughes at copper.ucs.indiana.edu
Mon Oct 29 23:48:52 AEST 1990


In article <1990Oct25.160937.28144 at edm.uucp> geoff at edm.uucp (Geoff Coleman) writes:
>	What do you mean by the guts of VMS and UNIX? If you are talking 
>system level programming and accessing devices then Unix is a big winner IMHO.
>Why you ask? Well any O/S who's language of choice for opening and controlling
>devices is FORTRAN (or BLISS) ala VMS has definite drawwbacks. I seem to 
>remember that when I wanted to open a tape drive I had to convert the  C 
>strings into structs with a length component etc. THe other obvious downfall
>of VMS from my point of view was the need to worry about the inifinite 
>combination of file types (fixed length records, fixed block size) versus the
>UNIX philosophy of a file is a file is a file.
>

This really isn't an argument...where is it stated that the language of
choice is FORTRAN or BLISS?  This has never been my impression or
experience.  Also, what does "a file is a file is a file" mean?  In Unix, 
a file is essentially a bytestream; a VMS (RMS actually) text file can be 
treated this way, and also gives you added benefits (ISAM, etc.) for other 
file formats.

The "downfall" you describe about structs with a length component
(they're called string descriptors) is how VMS achieves true language
independence.  It turns out that this IS awkward when programming in
C (particularly because after system service calls you have to null
terminate the strings yourself), but this is because most languages
do not use null terminated strings, and VMS simply does not favor one
language over another (even though DEC is supposedly rewriting most
of the kernel in C).

For the record, I'm a fan of both VMS and Unix...both have advantages, 
disadvantages, and their proper place.

/=========================================================================\\
||       Larry J. Hughes, Jr.        ||        hughes at ucs.indiana.edu        ||
||        Indiana University         ||                                      ||
||   University Computing Services   ||   "The person who knows everything   ||
||    750 N. State Road 46 Bypass    ||      has a lot to learn."            ||
||      Bloomington, IN  47405       ||                                      ||
||         (812) 855-9255            ||   Disclaimer: Same as my quote...    ||
 \\==========================================================================//



More information about the Comp.unix.programmer mailing list