MAP - Display the Mapping Context for a File
		    --------------------------------------------


MAP is a utility for RSX-11M, RSX-11M-PLUS and MicroRSX systems which is used to
examine the file header of a file and display mapping information statistics.

MAP is run:	MAP filename[,filename ...]

Where:	filename      - name for the file(s) to be MAPped. It may contain
			device, directory, name, extension and version number
			components. Multiple file names are allowed provided
			they are separated by ",". Wild card support has not yet
			been implemented. Elements from the file names are
			propagated down the command line as an aid to the user.
			There are no defaults for any part of the name except
			the standard system defaults (SY:[current]). 

MAP provides output as follows:

>map map.mac,.tsk,[0,0]indexf.sys,dr2:[abcdefghi]delete.me

Mapping information for . . . . . . . . . . : DR0:[370,7]MAP.MAC;1
Space allocated . . . . . . . . . . . . . . : 44 blocks.
File traversal path length  . . . . . . . . : 156 blocks.
Headers  (minimum, actual, efficiency)  . . : 1, 1, 100%
Pointers (minimum, actual, efficiency)  . . : 1, 4, 25%
Contiguity  . . . . . . . . . . . . . . . . : Discontiguous.
Discontiguous segments (no., min, max)  . . : 4, 3, 29.
 
Mapping information for . . . . . . . . . . : DR0:[370,7]MAP.TSK;40
Space allocated . . . . . . . . . . . . . . : 32 blocks.
File traversal path length  . . . . . . . . : 32 blocks.
Headers  (minimum, actual, efficiency)  . . : 1, 1, 100%
Pointers (minimum, actual, efficiency)  . . : 1, 1, 100%
Contiguity  . . . . . . . . . . . . . . . . : Marked as contiguous.
 
Mapping information for . . . . . . . . . . : DR0:[0,0]INDEXF.SYS;1
Space allocated . . . . . . . . . . . . . . : 4058 blocks.
File traversal path length  . . . . . . . . : 69896 blocks.
Headers  (minimum, actual, efficiency)  . . : 1, 1, 100%
Pointers (minimum, actual, efficiency)  . . : 16, 18, 88.9%
Contiguity  . . . . . . . . . . . . . . . . : Discontiguous.
Discontiguous segments (no., min, max)  . . : 2, 1, 4056

Mapping information for . . . . . . . . . . : DR2:[ABCDEFGHI]DELETE.ME;2
Space allocated . . . . . . . . . . . . . . : 33000 blocks.
File traversal path length  . . . . . . . . : 74058 blocks.
Headers  (minimum, actual, efficiency)  . . : 2, 2, 100%
Pointers (minimum, actual, efficiency)  . . : 129, 175, 73.7%
Contiguity  . . . . . . . . . . . . . . . . : Discontiguous.
Discontiguous segments (no., min, max)  . . : 50, 1, 12864 blocks.

MAP -- Version V01.04 - 19-Apr-88.
Copyright (C) 1988 - XDT Computer Consultants. All Rights Reserved.



MAP displays the file name and the number of blocks allocated to the file. The 
file traversal path is calculated and displayed. The traversal path is the 
geometric sum of the distances, in blocks, between file segments mapped by 
individual retrieval pointers. For a contiguously placed file this traversal 
path will be the same as the file size. For a fragmented file it will be larger.
Fragmented files which have individual fragments spread across a large range of 
the disc will have a higher traversal path than files which have their fragments
clustered around a small number of contiguous cylinders.

MAP then calculates the minimum number of file headers headers needed to map the
file and the number of headers actually used to map the file. The same
calculations are done for the retrieval pointers. The percentage efficiency of
header and pointer usage are calculated. 

MAP determines if the file is contiguous or not. If the file is marked as
contiguous (eg a task image) this is displayed. MAP reads all the retrieval
pointers and determines if the file is actually placed contiguously even if it
is not marked as being contiguous and will report "placed contiguously" or
"discontiguous". If the file is discontiguous the number of contiguous segments
and the size of the smallest and largest segment are displayed. 

MAP copes with RSX-11M-PLUS v3.0 named directories and logical name translation
if support for these is present. It has been written to run under any of the RSX
family. 


	Adrian Bottoms - XDT Computer Consultants - 19-Apr-88