JPH04336341A - File access control system - Google Patents

Abstract

PURPOSE:To decide an error unless a record type specified by an application program matches a file and to freely access a desired file whose contents are to be looked by the application program by receiving record type information on the file. CONSTITUTION:A record type information table 2 has a record type as one of pieces of file control information on files on a file device 6. The file collation part 1 of a file access control part 4 collates the record type requested by the application program 5 with the record type of the record type information table 2 and informs the application program 5 of record type information as the collation result.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a file access control system, and more particularly to a file access control system when files are accessed by executing an application program in a computer system.

0002

[Prior art] In the conventional file access control method,
The record format of records stored in a file is determined by the record definition within the application program, which depends on how the accessing application program itself is created.

0003

[Problem to be Solved by the Invention] In the conventional file access control method described above, even if the record definition of the application program when referencing a file differs from the record definition when the file was created, it is not possible to Although the program operates like this, the disadvantage is that correct processing results cannot be obtained because the record definitions are different. Furthermore, in conventional file access control methods, only program definitions exist for the record format information on a file, so when you simply want to view the contents of a file, you can use a format that ignores the record format (for example, It can only be viewed in a hexadecimal format (print format), and if you want to print in the correct format, you have to provide information on the record format each time, which is inconvenient.

0004

[Means for Solving the Problems] The file access control method of the present invention is a file access control method for a computer system having a file device such as a magnetic disk device or a floppy disk device. It has a record type information table that has a record type as one of the information, and the record type information table and the record type requested by an application program that issued an access request under the control of an operating system that collectively controls access to files. The file matching unit includes a file matching unit that matches the record type of the file on the file device located in the storage device and notifies the requesting application program of the record type information of the matching result.

[0005]

Embodiments Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of the file access control method of the present invention. The application program 5 shown in FIG. 1 is a program that accesses files on the file device 6. The application program 5 shown in FIG. For each file secured on the file device 6, a file label 3 as file management information is created on the same file device 6 for each file. In addition, in this embodiment, a record type information table 2 indicating the record type of the file is used.
is secured in a location different from the file label 3, and a pointer 31 indicating the location is provided in the file label 3, thereby linking the files.

FIG. 2 shows the record type information table 2 in FIG.
It is an information configuration diagram showing an example. The file label 3 and record information table 2 are created at the time of allocating a file. As shown in Figure 2,
The record type information table 2 has an end ID after repeating the item length, item attribute, and item name as many times as the number of items from the beginning of the record for each item that is an element constituting the record.

[0008] Therefore, the application program 5 in FIG. 1 issues an access request to the file access control section 4 in order to access the file.

FIG. 3 is a flowchart showing an example of the operation of the file access control section 4 shown in FIG. The file access control unit 4 is generally provided in a computer system as a function of the operating system.
Referring to FIG. 3, first, a file access request action is received from the application program 5 (step 301). Next, it is determined whether the received action is file verification (step 302), and if it is other than file verification, the process is completed within the file access control unit 4 (step 303), and the result is returned to the application program 5 (step 304). Step 30
If the action is file verification in step 2, file verification unit 1 is called (step 305).

FIG. 4 is a flowchart showing an example of the operation of the file matching section 1 of FIG. The file matching unit 1 called by the file access control unit 4 performs the following operations as shown in FIG.
First, the action parameters passed when the application program 5 requests a file open are checked to determine whether the mode is collation mode or notification mode (step 40).
1) If the verification mode is selected, read the record type information table 2 linked by the pointer 31 from the file label 3 (step 402), compare it with the record definition parameters of the application program 5 (step 403), and send the result to the application program. 5 (step 404). Also, if it is in the notification mode, read the record type information table 2 (step 4).
05), the record type information is returned to the application program 5 (step 406). In either mode, the process is returned to the file access control unit 4 (step 407).

Returning to FIG. 3 again, in step 306, control is returned to the application program 5 that made the access request to complete the access request.

0012

[Effects of the Invention] As explained above, the file access control method of the present invention has the following effects by including the file matching section of the record type information table as one of the file management information. .

(1) Processing can be performed only when the record definition of the application program itself and the record type information match, and an error can be generated when they do not match.

(2) In the notification mode, an accessible record definition can be created based on the record type information notified to the application program, so it is possible to create a program without specifying the files that can be accessed. Become. As an example of application in this case, for example, in response to a request to simply view the contents of a file, conventional technology ignores the record format.
Previously, it was only possible to print in decimal format, but now it is possible to edit and output according to the record type information, making it possible to print the contents more clearly.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of a file access control method of the present invention.

FIG. 2 is an information configuration diagram showing an example of the record type information table 2 of FIG. 1;

FIG. 3 is a flowchart showing an example of the operation of the file access control unit 4 in FIG. 1;

FIG. 4 is a flowchart showing an example of the operation of the file matching unit 1 in FIG. 1;

[Explanation of symbols]

1 File collation unit 2 Record type information table 3 File label 4 File access control unit 5 Application program 6 File device 31 Pointer

Claims (1)

[Claims] 1. In a file access control method for a computer system having a file device such as a magnetic disk device or a floppy disk device, record type information having a record type is one of file management information for a file on the file device. The record type requested by the application program that issued the access request and the record type of the file on the file device in the record type information table are stored under the control of an operating system that collectively controls access to files. 1. A file access control method comprising: a file matching unit that performs the matching and notifies the requesting application program of the record type information of the matching result.