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random i/o tools
Date: 11 Jul 90 02:27:44 GMT
From: barmar@Think.COM (Barry Margolin)
Date: Tue, 10 Jul 90 16:57:09 MDT
From: bein@boulder.Colorado.EDU (Jonathan Bein)
Does anyone in the SLUG community have or know of Symbolics
software that can be used for doing random file i/o? I am doing
some database work and need tools for disk based hashing, B-trees, etc.
to integrate in the software I am developing. I am aware that similar
software components are available in Statiuc, but I need random i/o
utilities that are not embeeded in a proprietary product.
You can do random I/O with the standard stream I/O facilities in Genera.
The Common Lisp FILE-POSITION function can be used on binary streams to
go to any position in the file; this isn't permitted for character
streams because character set translations and character style
expansions make it difficult to determine the physical location in the
file corresponding to a character position.
I think we have an application here that does a binary search on a file of
STRING-CHARs. We gave these keyword options to OPEN: :direct t
:element-type 'string-char. Then we used FILE-POSITION to move around.
The :direct keyword is a Symbolics extension, and therefore not portable
(well, at least it used not to be portable.