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C and UTC questions?

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The Question is:

 
How can I determine the version of C compiler running?
How can I determine if UTC is available: because gmtime() seems to return
null.
 


The Answer is :

 
  Most (all?) versions of DEC C support a /VERSION qualifier, which will
  display the compiler version:
 
    CC [/DECC] /VERSION NLA0:
 
  Under either compiler, the following brute-force technique -- looking
  at the version information in the listings -- can also be used:
 
    CC [/DECC] [/VAXC] NLA0:/LIST=TT:/NOOBJECT
 
  Baseline system UTC support was added to OpenVMS V6.0, with subsequent
  enhancements in later releases.  The C gmtime call was first supported
  with OpenVMS V6.1.
 
	--
 
  The last version of VAX C was V3.2 -- the current version of C (and
  specifically of DEC C) is V5.7.  (DEC C V4.0 is an ANSI C compiler,
  and it replaced the non-ANSI C VAX C V3.2 compiler many years ago.)
 
  Various DEC C versions also support and can be used on OpenVMS VAX
  V5.5-2, and both DEC C and VAX C can be installed on the same OpenVMS
  VAX system, and the proper compiler can then be selected as required.
  DEC C also includes a mode where it can compile nearly all VAX C coding
  constructs.
 
  OpenVMS VAX V5.5-2 is also rather old -- the current version of OpenVMS
  is V7.1.  The C run-time libraries -- the libraries ship with OpenVMS
  -- have also seen a number of new C functions added into the OpenVMS
  V7.0 and later releases...
 
  DEC C V5.6 and later also include a "backport" library, which allows
  more recent C library calls to be used from programs developed on older
  OpenVMS versions.
 

answer written or last revised on ( 10-SEP-1998 )

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