System for concentrically converting file format

Description: TECHNICAL FIELD [Detailed description of the invention]

【0001】

[Industrial application field]

The present invention relates to CSS (client-server system), and particularly to a system in which a server intensively converts a file format.

【0002】

[Conventional technology]

In recent years, CSS has been put into practical use in which a plurality of terminals are used as client machines and these client machines and server machines are connected by a network. Since these terminals generally have different character code systems and file formats, it is necessary to convert the character code and the file format in order to exchange files with other terminals and server machines. For example, Japanese Patent Application Laid-Open No. 4-178827 describes a method for mutually converting an arbitrary character code into another arbitrary character code.

【0003】

[Problems to be Solved by the Invention]

In a CSS composed of multiple terminals with different character code systems and file formats, a file with a unique character code system and file format created by each terminal is registered, and the file is registered with a different character code system and file format. When reading with a file format terminal, it is common to select and execute a conversion program owned by each terminal or a conversion program owned by the server to perform character code conversion and file format conversion. Assuming that each terminal targets all character code systems and file formats for conversion in this way, in the case of m types of character codes and n types of file formats, n (n-1) types and n (n-1) types can be converted by character code conversion. File conversion requires m (m-1) types of conversion programs, and the number of conversion programs is enormous. It is very difficult for the user of each terminal to definitely select the desired conversion program from these enormous number of conversion programs. Moreover, it is difficult to maintain and manage such a huge number of conversion programs on each terminal.

【0004】

An object of the present invention is to provide a system in which all conversion programs are integrated into a server machine, and each terminal eliminates the trouble of selecting a conversion program and managing the conversion program.

【0005】

[Means for solving problems]

The following files refer to data files, document files, etc. that store a plurality of data records, and do not include program files. The substance of the file is composed of character code, graphic information, image information, voice information, and the like. Generally, the format of a file differs depending on the terminal or the application program that handles the file. For example, document files are allowed several formats, and the format you choose depends on the application program. Files such as the display screen format also differ depending on the application program that handles them. In the case of a file containing graphic information and image information, the data structure and command code generally differ depending on the terminal and the application program. That is, in general, the file format differs depending on the terminal, and even if the terminal is of the same type, it differs depending on the application program. Further, the difference in the file entity may be accompanied not only by the difference in the file format but also by the difference in the character code and the control code.

【0006】

In the present invention, when a terminal as a client issues a read request for a shared file to a server by designating information about a file format and a character code unique to the terminal and the application program, the server is designated. Execute the target conversion program by referring to the table that stores the correspondence between the specified file format and the corresponding conversion program and the table that stores the correspondence between the specified character code and the corresponding conversion program. It features a system that converts the file format and character code of a shared file into a client-specific file format and character code.

【0007】

[Action]

Each terminal simply issues a read request for the shared file to the server machine by specifying information about the client-specific file format and character code, and the server machine specifies the shared file in the specified file format and character code system. Since it is converted to the above file and transferred to the terminal, each terminal does not need to be aware of the file format and character code of the shared file, and does not need to maintain or manage the conversion program.

【0008】

[Example]

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

【0009】

FIG. 1 is a system configuration diagram of a CSS (client / server system) showing an embodiment of the present invention. In FIG. 1, 10 is a server machine, 20 to 50 are terminals serving as clients, and 60 is a communication line connecting each terminal and a server. Reference numeral 70 denotes a shared file database that is connected to the server machine 10 and stores a plurality of shared files that are commonly accessed from the terminals 20 to 50, and has a file storage table 71 that stores the format and access level of the shared files. .. 80 is a conversion database that stores a table that is connected to the server machine 10 and is referred to when performing character code conversion and file format conversion of the file transferred between each terminal machine 20 to 50 and the server machine 10. , Character code conversion program storage table 81, file format conversion program storage table 82, and access level storage table 83. 11 is a program provided in the server machine 10. For the shared file read from the shared file database 70 and the shared file before being written to the shared file database 70, refer to the table on the conversion database 80 for character code conversion and file format. It is a file conversion mechanism that converts. The shared file database 70 and the conversion database 80 are realized by an external storage device connected to the server machine 10. In the shared file database 70, the character code ID is 1 and the file format ID is unified to A1, B1, C1, ... Depending on the shared file, and each file has an access level. Each terminal 20 to 50 has a unique character code, a file format, and a unique character code ID, a file format ID, and a user ID according to the access authority for the file. For example, the character code ID of the terminal 20 is 2, the file format ID is A2, B2, C2, ... And the user ID is y2, the character code ID of the terminal 30 is 3, the file format ID is A3, B3, C3. , ..., etc. and the user ID is y3, ..., etc.

【0010】

FIG. 2A is a diagram showing the data structure of the file storage table 71. In the file storage table 71, the file format IDs are A1, B1, C1, ..., and the access level IDs are α, β, respectively, corresponding to the shared files whose file IDs are A, B, C, ... It has a file address indicating the storage location of each shared file on γ, ..., And the shared file database 70. FIG. 2B is a diagram showing the data structure of the character code conversion program storage table 81. The character code conversion program storage table 81 corresponds to a character code set having a character code ID of 2, 3, ..., And has a conversion program to a character code set having a character code ID of 1 and a character code ID of 1. Stores the start address of the inverse conversion program from the character code set of to the character code set with character code IDs 2, 3, ..., respectively. Here, the conversion program and the inverse conversion program may be a conversion table and an inverse conversion table. FIG. 2C is a diagram showing the data structure of the file format conversion program storage table 82. , File format conversion program storage table 82 is a conversion program from shared files with file format IDs A1, B1, ... To files with file format IDs Ai, Bi, ... (i = 2 ~ 5), respectively. And stores the start address of the inverse conversion program from the file whose file format ID is Ai, Bi, ... To the shared file whose file format ID is A1, B1, ..., respectively. FIG. 2D is a diagram showing the data structure of the access level storage table 83. In the access level storage table 83, the access level IDs are α, β, The access level is stored for each shared file. Here, the access level sets the permission / non-permission of file read and the permission / disapproval of file write for all users, and the permission / disapproval of file read and the permission / disapproval of file write for a specific user group. Is. The upper few digits of the user ID represent the user group ID.

【0011】

FIG. 3 is a flowchart showing the processing flow of the server machine 10 when the terminal reads the shared file in the shared file database 70. Here, a terminal 20 will be described as an example of the terminal. The terminal 20 requests the server machine 10 to read the shared file whose file ID is A (step 101). This read request is accompanied by parameters with a character code ID of 2, a file format ID of A2, and a user ID of y2. The server machine 10 refers to the file storage table 71 and extracts the file format ID of the shared file whose file ID is A and the access level ID of α (step 102). Next, the server machine 10 refers to the access level storage table 83 and determines whether or not the shared file A can be accessed from the user ID y2 and the access level ID α (step 103). If it is inaccessible, a message is displayed and the process is interrupted (step 104). When accessible, the file conversion mechanism 11 reads the character code conversion program a2 and the file format conversion program I2 with reference to the character code conversion program storage table 81 and the file format conversion program storage table 82, and executes these programs. (Step 105). As a result, the file converted into the character code 2 of the terminal 20 and the file format A2 is completed, the server machine 10 sends this file to the terminal 20, and the terminal 20 performs an editing process (step 106). Even when the terminal updates the shared file, the server 10 makes a request to update the shared file in step 101 above, and if it is accessible through steps 102 and 103 above, the file entity to be updated is transmitted from the terminal 20 from the terminal 20. Transfer to the server machine 10, convert the character code and file format in step 105, and replace the converted file with the original file in the shared file database 70 and store it. However, in the case of update, the programs executed in step 105 are the character code conversion program- (a2) and the file format conversion program- (I2).

【0012】

FIG. 4 is a flowchart showing the processing flow of the server machine 10 when the terminal creates a new shared file in the shared file database 70. Here, a terminal 20 will be described as an example of the terminal. The terminal 20 requests the server machine 10 to store the shared file whose file ID is A (step 201). This storage request is accompanied by a parameter with a character code ID of 2 and a file format ID of A2, and a file entity to be created. The server machine 10 refers to the file format conversion program storage table 82 and acquires the file format ID A1 of the shared file whose file format ID corresponds to A2 (step 202). The file conversion mechanism 11 refers to the character code conversion program storage table 81 and the file format conversion program storage table 82, reads the character code conversion program-(a2) and the file conversion program-(I2), and executes these programs ( Step 203). The server machine 10 displays the access level type in the access level storage table 83 to the terminal machine 20 and requests the terminal machine 20 to input the access level (step 204). The terminal 20 selects an access level from the displayed access level contents (step 205). The server machine 10 adds a new entry with the file ID A, the file format ID A1, and the access level ID corresponding to the access level selected as the access level ID to the file storage table 71, and adds the converted shared file. Store in shared file database 70 (step 206).

【0013】

[Effect of the invention]

According to the present invention, since the server recognizes the difference in the character code system and the file format and automatically converts the file, the user of each terminal can use the shared file without being aware of the difference in the character code system and the file format. It can be used. In addition, by unifying the character code system and file format of the shared file, the number of conversion programs in the system as a whole can be significantly reduced.

[Simple explanation of drawings]

[Figure 1]

It is a system configuration block diagram which shows one Example of this invention.

[Figure 2]

It is a figure which shows the data format of various tables which are referred and updated in an Example.

[Fig. 3]

It is a flowchart which shows the process flow of the file read process in an Example.

[Fig. 4]

It is a flowchart which shows the process flow of the file storage process in an Example.

[Explanation of symbols]

10 Server machine 20, 30, 40, 50 ... Terminal 70 Shared file database 11 File conversion mechanism 81 Character code conversion program storage table 82 File format conversion program storage table