Applicable release versions: AP, AP 6.1, R83
|Description||describes the mechanism by which the Pick System establishes the disk address of a file.
This item contains ASCII-numeric data which describes the file location in virtual memory.
These numbers are the "base" frame id and the modulo" which resolves to drive, cylinder, sector and head.
File-defining items are often called "fid" or "d-pointers" in reference to the dictionary code in attribute 1.
File-defining items define the nature of the item-id (attribute 0). File-defining items define the relationships between files. File-defining items contain default macros for Access and Update.
In AP, information about the file itself, its physical extents, status, indices, etc., is stored in a separate data structure called the "file control block". This data structure is unavailable to the user except indirectly through the file-defining item.
Attribute 0: Item-Id
Attribute 0 contains the name of the file being defined.
Attribute 1: Dictionary Code (d/code)
For file-defining items this attribute must contain a "d". The following characters may be added to the dictionary code to further define the item:
l Logs any updates to the transaction logger.
n Disable update protection on a file even if global update protection is enabled. May not be used with the "u" option.
p Primary filespace contains only pointer items.
s Item-ids are case sensitive.
u Enable update protection on a file even if global update protection is disabled. May not be used with the "n" option.
x Does not save file contents on file save. The file does not exist on restore.
y Does not save file contents on file save. An empty file of the same modulo exists after restore.
Attribute 2: Base
Attribute 2 contains the frame identification number of the associated file. The value assigned to the base of the file is reflected in the message that displays to the screen when the file is created.
Attribute 3: Modulo
Attribute 3 contains the number of contiguous frames in the primary file space of the file. The value assigned to the modulo of the file is reflected in the message that displays to the screen when the file is created. A file can not be created unless there is a large enough block of contiguous space to handle the requested file size.
Attribute 4: Reserved and Unavailable
Attribute 5: Retrieval Lock
In the md, this attribute controls access to dictionaries. In dict this attribute controls access to files. One of the user's lock codes in attribute 5 of the users item in the users file must match the first lock code specified in this attribute in order to access the appropriate dictionary. Multiple lock codes are treated as multiple values and are separated by value marks within this attribute.
Attribute 6: Update Lock
The update lock attribute controls access to account master dictionaries or file dictionaries for update. One of the user's lock codes in attribute 6 of the users item in the users file must match the first lock code specified in this attribute in order to update the appropriate dictionary. Multiple lock codes are treated as multiple values and are separated by value marks within this attribute.
Attribute 7: Reserved and Unavailable
Attribute 8: Correlative (see "correlative").
Attribute 8 contains processing codes described in "Processing Codes". Processing codes specified in this attribute allow a file to function as an application by pre- and post-processing data, and are applied when an item in this file is updated. This feature is not available in R83 releases.
Attribute 9: Justification
The attribute type contains codes used to specify justification for the item-id:
l Left justification with word wrap on overflow. This option will break on a word.
r Right justification with overflow to the left.
t Left justification with word wrap on overflow. This option word wraps, only breaking on a space.
u Left justification with overflow to the right.
w Processes through OP before listing. Any valid OP command may follow this code or be used in this attribute. This code only works for non-columnar formats. "Dot" commands following the 'w' are prefixed to the attribute. A second value may contain "dot" commands to be postfixed to the attribute for Output Processing.
ww Processes all attributes from the current attribute through the end of the item through OP before listing. This code works for non-columnar formats only. "Dot" commands following the 'ww' are prefixed to the first attribute. Thus, they are executed before the output data. A second value may contain dot commands to be postfixed to the item for Output Processing.
x Used with "l", "r", or "t" to expand display field to fill the terminal or printer width as specified in the term command.
Attribute 10: Column Width
The column width attribute is used to define the number of character spaces to be allocated for displaying the item-id on Access reports.
Attribute 11: Reserved and Unavailable
Attribute 12: Reserved and Unavailable
Attribute 13: Reallocation
The reallocation attribute is used in the save and restore process to redefine the value of the modulo of the associated file.
Attribute 14: Input-Conversion (see "input-conversion")
This attribute contains processing codes to be applied to data prior to entry.
Attribute 15: Macro
The "macro" attribute contains the attribute names to be used as default input specifications for the Update processor. The attribute-defining items listed here are used as the default output list by Access if no "output-macro" is specified, and are automatically listed when any Access verb that allows attribute-defining items is invoked and no attribute names are specified. Attribute names in the list are separated by spaces. If the specified attribute name does not exist in the dictionary, it is ignored.
The "macro" attribute may be multi-valued. When multi-valued macros are used, the macro to be used by Access or the Update processor is determined by calling a Pick/BASIC program from the "input-conversion" of the "d-pointer" that assigns a value number to access(18). This value number corresponds to the value number of the macro to be used.
To automatically prompt for an item-id, the "id-prompt" modifier or the "i" UP option may be used.
Attribute 16: Output-Macro
If present, this becomes the default "output" macro. Otherwise, attribute 15, if present, is used as the output macro. The purpose of having both the "macro" and the "output-macro" is to use different default attribute-defining items for Access and UP.
Attribute 17: Description
This attribute is used for comments and descriptions concerning the function of the current file. "?" gets the help message from the item in the Update processor.
Attribute 18: Reserved
Attribute 19: Reserved
Attribute 20: hotkey.all
Attribute 21: hotkey1
Attribute 22: hotkey2
Attribute 23: hotkey3
Attribute 24: hotkey4
Attribute 25: hotkey5
Attribute 26: hotkey6
Attribute 27: hotkey7
Attribute 28: hotkey8
Attribute 29: hotkey9
Attribute 30: hotkey0