JPH04349545A - File system - Google Patents

Abstract

PURPOSE:To limit an access to a file, and to prevent an illegal access executed by a third person, in an OS of a single user. CONSTITUTION:An MS-DOS compatible file system 13 can access a floppy disk 14 and a hard disk 15 which an OS (MS-DOS) 5 of a single user cannot recognize and in which a format is varied partially, and only a data base program 10 actuated by the MS-DOS 5 can execute a request for accessing the floppy disk 14, etc., to the MS-DOS compatible file system 13.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a database file system suitable for file management.

0002

[Prior Art] Traditionally, database programs are configured on an operating system (hereinafter referred to as OS).
The OS includes single-user OS such as MS-DOS (registered trademark of Microsoft Corporation) and UNI
X (OS developed and licensed by AT&T in the US)
There are multitasking and multiuser OSs such as A database file system based on a database program on a single-user OS such as MS-DOS was created on the premise that there is no possibility of a third party accessing the file.

0003

[Problem to be Solved by the Invention] In a single-user OS such as the above-mentioned MS-DOS, anyone with knowledge of MS-DOS can illegally access the database file system using the MS-DOS database program. . This is particularly noticeable when a single machine is shared by multiple users, and it is not possible to restrict access by others to database files stored on the machine's hard disk. An object of the present invention is to provide a database file system capable of restricting access to files in a single-user OS and preventing illegal access by a third party.

0004

[Means for Solving the Problems] The present invention provides an input means for inputting commands or data, and a first file system formatted by the single-user OS in a file system of a computer controlled and processed by a single-user OS. A first file access means capable of accessing a file; and a second file that is formatted by changing a part of the format of the single user OS so that it cannot be recognized by the single user OS. a second file access means capable of accessing the second file; a file access request means activated by the single user OS and capable of requesting the second file access means to access the second file; a file determining means for determining whether a command to access a file from the means is a first file or a second file; and a file determining means for determining whether the command to access a file is an access to the first file. When it is determined, the first file accessing means accesses the first file, and when it is determined that the file access command is to access the second file, the file access requesting means control processing means for requesting the second file accessing means to access the second file from the file access requesting means and causing the second file to be accessed only when the file access requesting means is activated. It is a file system that

[0005]

[Operation] In a file system that uses a single-user OS, in order to access a second file that cannot be recognized by the single-user OS, access a file system that allows access to this second file. Therefore, access to the second file can be restricted.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be explained with reference to an embodiment shown in the drawings. FIG. 1 is a block diagram showing the hardware configuration of the present invention, FIG. 2 is a conceptual diagram, and FIG. 3 is a flow chart showing the operation. 1 is a keyboard for inputting commands and data; 2 is a display device; 3 is an external storage device such as a hard disk or floppy disk; 4 is a control processing unit for processing commands and data input from the keyboard 1; is configured, for example, as a personal computer.

Next, a case will be described in which a file system is constructed using the MS-DOS as a single user OS, as shown in FIG. MS-DOS5 is
It has a file I/F 6 and other lower modules of I/F 7. The file I/F 6 of MS-DOS 5 accesses external storage devices such as a floppy disk 8 in which files created by MS-DOS 5 are stored and a hard disk (participant area) 9 recognized by MS-DOS 5. . The database program 10 is
User I/F 11 and DB (database) file I
It has a lower module of /F12, and accesses MS-DOS5 by requesting MS-DOS5 through user I/F11 except for file access, and accesses to files are performed by MS-D (described later) through DB file I/F12.
The database program 10 is configured to be able to access only the OS compatible file system 13, and is stored in a storage device (for example, a hard disk) within the control processing unit 4, for example.

The MS-DOS compatible file system 13 consists of a compatible file for the floppy disk 14, which is formatted by changing a part of the MS-DOS5 format so that it cannot be recognized by MS-DOS5, and a compatible file for the MS-DOS5.
5 is a program module configured to be able to access compatible files on a hard disk (participant area) 15 that is recognized as another OS, and it is a storage device (for example, a hard disk) in the control processing unit 4 along with the database program 10. and is loaded into the main memory (not shown) of the control processing section 4 by the MS-DOS 5.

Next, the operation of the present invention will be explained with reference to the flowchart shown in FIG. First, the database program 10 runs on MS-DOS in response to a command from the keyboard 1.
5, for example, the floppy disk 8 of the external storage device 3.
MS-D
An OS compatible file system will also start. Thereafter, when commands etc. are input from the keyboard 1, the database program 10 handles processing other than accessing files by the user I/O.
Processing is requested to MS-DOS5 by F11.

[0010] Now, when a command to access a file is input from the keyboard 1 in step S1, the process proceeds to step S1.
At step 2, it is determined whether the access is to a regular file, that is, MS-DOS5, or a compatible file. For accessing MS-DOS5 files,
A file on the floppy disk 8 or hard disk 9 is accessed by the file I/F 6 of the MS-DOS 5 (step S3). If the access to the file is to a compatible file, it is determined in step S4 whether the access to the file is to a compatible file, and if it is a compatible file, the process advances to step S5.

[0011] In step S5, it is determined whether the database program 10 is running. Since the database program 10 has been loaded into the main memory of the control processing section 4, it is determined that the database program 10 is activated, and the process advances to step S6. Step S6
Then, the MS-DOS compatible file system 13 accesses the floppy disk 14 or hard disk 15. If the database program 10 is not running, it is determined in step S5 that the database program 10 is not running, and the process proceeds to step S7, where an error message is displayed indicating that the file cannot be accessed or the file cannot be found. .

As described above, the present invention prevents access to compatible files on the floppy disk 14 or hard disk 15 if the database program 10 is not started when the user or the authorized user is not using it. , unauthorized access by a third party to the floppy disk 14 or hard disk 15 can be prevented.

Effects of the Invention As detailed above, according to the present invention, when the user or the authorized user does not use the computer, files that cannot be recognized by the single user's OS cannot be accessed. OS
File access management functions can be dramatically improved in file systems that use .

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the hardware configuration of a file system according to an embodiment of the present invention.

FIG. 2 is a conceptual diagram for explaining the embodiment.

FIG. 3 is a flowchart for explaining the operation of the embodiment.

[Explanation of symbols]

1...Keyboard, 2...Display device, 3...External storage device, 4
...Control processing unit, 5...MS-DOS, 10...Database program, 13...MS-DOS compatible file system.

Claims (1)

[Claims] 1. A file system of a computer controlled and processed by a single-user OS, comprising: input means for inputting commands or data; and a first file system capable of accessing a first file formatted by the single-user OS. a second file access means that can access a second file that has been formatted by changing a part of the format of the single user OS so that it cannot be recognized by the single user OS; means, a file access request means activated by the single user OS and capable of requesting the second file access means to access the second file; and access to the file from the input means. a file discriminating means for discriminating whether the command is a first file or a second file; and when the file discriminating means determines that the file access command is an access to the first file; When the first file is accessed by the first file access means and it is determined that the file access command is to access the second file, only when the file access request means is activated. and control processing means for requesting the second file access means to access the second file from the file access request means and causing the second file access means to access the second file.