...here.
See ADAM Programmer Note 7 for a description of these routines.
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...reside.
On Starlink systems this directory will normally be called /star/starlink/lib/hds.
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...program.
This will work even if the object was originally created on a different computer which formats its numbers differently.
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..."mapping".
This terminology derives from the facility provided by some operating systems for mapping the contents of files into the computer's memory, so that they appear as if they are arrays of numbers directly accessible to a program. Although HDS exploits this technique when available, other techniques can also be used to simulate this behaviour, so HDS does not depend on the operating system providing this facility.
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...facility,
This technique works because Fortran normally passes the address of an array to a subroutine, so the routine is fooled into thinking it's getting an array.
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...function
We illustrate the use of the CNF_PVAL function in this document, although in most existing software which calls HDS this function is not used. It has been introduced because of the possibility that Fortran software which stores pointers in 32-bit INTEGERs may need to execute in circumstances where 64 bits are required to store a memory pointer. The purpose of the CNF_PVAL function is then to expand the pointer value out to its full size before use, if necessary. On currently-supported platforms, this step is not normally needed, so use of CNF_PVAL may considered optional. However, its inclusion in new software is recommended as a useful precaution.
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...DAT__NOLOC
As defined in the include file DAT_PAR.
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...invalid).
You are advised not to depend on this mechanism for annulling secondary locators because you will not normally have complete control over a file's reference count (for instance, it may be opened independently for some other purpose in the same piece of software).
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...blocks.
An HDS block is 512 bytes.
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...blocks
An HDS block is 512 bytes.
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...blocks
An HDS block is 512 bytes.
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...blocks
An HDS block is 512 bytes.
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...libraries
On non-Starlink systems you may need to specify a different directory if you have not installed the Starlink software in the standard place.
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...characters
That is, anything except alphanumeric characters, slash `/', period `.', underscore `_' and minus `-'.
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HDS Hierarchical Data System
Starlink User Note 92
R.F. Warren-Smith & M.D. Lawden
23rd February 1999
E-mail:rfws@star.rl.ac.uk

Copyright (C) 1999 Central Laboratory of the Research Councils