UD IC - Unsave Document - In-core, Retrieve register values

(03/30/12)

PURPOSE

To access a document file, either from disk or from an in-core document file (array), and retrieve registers from a specified key. If used with a on-disk document file then the whole file's contents are stored as an in-core document file (array) for further fast accesses within this session. Ten document files with unlimited keys each can be stored concurrently in-core.
'UD IC' should usually be used when more than one access to a large document file takes place.
This operation can also be used with an existing in-core document file (array) created with 'SD IC' 'UD ICE' terminates access to current in-core image of the document file specified, and allows access to a different document file after another 'UD IC' operation.   Example.

SEE ALSO

SD IC [Save Document - In Core, Save registers]
UD ICE [Unsave Document - End use of In Core document file]
UD [Unsave Document]
UD S [Unsave Document - Sequential search]
SD IC [Save Document - In Core, Save registers]
UD NEXT [Unsave Document - Next line]

USAGE

.OPERATION: UD IC <KEY>, [r1],[r2],[r3]

[WHERE: <KEY> is the key; [r1]... are up to 100 register variables to be filled.
Examples:
E1.    UD IC 300,[r1],[r2],[r3]    (KEY is an explicit number)
E2.    UD IC [k],[r1],[r2],[r3]    (KEY is contained in register variable:[k])
E3.    UD IC I,[r1],[r2],[r3]    (KEY is a DO-LOOP index)]

.INPUT DOCUMENT FILE: ADC998
[Enter the name of the document file previously created by a 'SD', 'SD IC', or other operation.]

[In example E1, let's say the document file has the first 490 keys filled. The operation listed above will cause all 490 x 4 numbers of the document file to be stored for future access within this session, and will fill registers [r1]=30, [r2]=1.5 and [r3]=270 with the values stored under key 300. Subsequent access to any other key present in the file (namely 1 ... 490), e.g.
  UD IC 410,[r1],[r2],[r3]
will quickly look up the values stored under key 410 in the in-core image, without the need to access the file.

IMPORTANT: only a imited number of document files may be accessed concurrently with 'UD IC'. Once the limit is reached one of the current files must be cleared by a 'UD ICE' operation. An attempt to apply 'UD IC' to a additional document file before execution of a 'UD ICE' operation to free the area reserved for data from an existing file will result in an error message.]

NOTES

  1. 'Even though it is not advisable, because of its slow speed, it should be mentioned that a operation 'UD' without the in-core option may be applied to a file currently existing as in-core image, without causing interference.

  2. Use 'UD' if you want to retrieve comment keys.

SUBROUTINES

UDOCIC, OPENDOC, LUNDOC

CALLER

DRIV3

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