JP2001142759A - Method for performing access to file system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To unnecessitate the change of a program for the operation of a hierarchical directory, which is required in a conventional manner, when the program which is operated in a computer system having the hierarchical directory and which includes API using the hierarchical directory is implanted onto a computer not having the hierarchical directory, and moreover, to operate even an existing file by the similar API. SOLUTION: A hierarchical directory interchangeable file system for mapping with a conventional file system, an API processing program for performing access to the hierarchical directory, a plane file for storing the plurality of files in one conventional file and a table for managing device information or mapping information of the hierarchical directory interchangeable file system and the actual file are arranged in the computer system which does not have the hierarchical directory.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a file system of a computer system, and more particularly to an interface for operating a file system in a computer system having no hierarchical directory.

[0002]

2. Description of the Related Art As shown in FIG. 7, an API using a hierarchical directory on a computer system 7-1 having a hierarchical directory and an AP using a processing program 7-3 thereof.
(Application Program) When porting 7-2 to a computer system 7-5 having no hierarchical directory, a computer system having no hierarchical directory has a sequential data set 7-7 having no hierarchical directory structure,
Since there is only a file system with a non-hierarchical directory structure such as a partitioned data set 7-8, the AP 7
6, the part using the API that uses the hierarchical directory is modified and executed.

On the other hand, as a technique for treating a file system having no hierarchical directory as a file system having a hierarchical directory, a delimiter as described in Japanese Patent Application Laid-Open No. Hei 9-114724 is converted as a directory, for example, "DIR1.FILE1". The file "/
For example, a method has been considered in which a file system having no hierarchical directory is made to look like a file system having a hierarchical directory, for example, by converting the file system into a file system having a hierarchical directory by converting the file system into a file system having a hierarchical directory, such as DIR1 / FILE1 and operating from a client computer system connected to a network.

As described above, in a computer system having no hierarchical directory, it is difficult to provide a hierarchical directory in consideration of the structure of a file system and compatibility with an old system. The directory-structured file system was resolved in a way that made it look like an apparently hierarchical directory structure.

A file system having a hierarchical directory structure generally used in PC / WS has a format in which directory information and data of each file are stored in the same file system.

[0006]

In the above method, a conversion mechanism is used, and since a hierarchical directory does not actually exist, an approximate hierarchical directory operation was possible. However, it is not possible to set an access right for each directory, set user information in the directory, and the like, and it is not possible to execute details. In addition, some remodeling was necessary.

Further, since a file system having a hierarchical directory structure generally used in PC / WS has a format in which file data is stored in the file system, the data storage format and the type of file system are different. There is no compatibility between different existing non-hierarchical directory structure file systems. For this reason, PC /
Implementing a file system having a hierarchical directory structure generally used in WS has a problem that the existing file system having a non-hierarchical directory structure cannot be used at all.

According to the present invention, when a program, which operates on a computer system having a hierarchical directory and uses an API that uses a hierarchical directory, is ported to a computer having no hierarchical directory, the hierarchical directory conventionally required is manipulated. It is an object of the present invention to make it unnecessary to change a program at a location where the file is to be changed, and to enable an existing file to be operated with a similar API.

[0009]

An object of the present invention is to provide a computer system having no hierarchical directory, a hierarchical directory compatible file system for mapping with a conventional file system, and an A for accessing a hierarchical directory.
A PI processing program, a plain file for storing a plurality of files in a conventional file, a table for managing a hierarchical directory compatible file system and device information and mapping information of actual files are provided. When an application program accesses a file, This is achieved by determining the type of a file including a plain file and an existing file, and accessing the file using an access method and a data storage format according to the file type.

[0010]

FIG. 1 shows the configuration of an embodiment of the present invention. Computer system 1-1 without hierarchical directory
(For example, a mainframe or the like) includes a sequential data set 1-7 having no hierarchical directory structure and a partitioned data set 1
A conventional file system having a non-hierarchical directory structure such as -6 exists. Such a conventional file system is mapped to a conventional file system so that it can be treated as a file system having a hierarchical directory structure.
A hierarchical directory compatible file system 1-5 is prepared.

In general, a file system having a hierarchical directory structure uses a plain file that fills data to fill a record. Since a file system having such a data storage format does not exist in a conventional file system, the plain file 1-8
Also prepared.

An API using a hierarchical directory
The API and the API processing program 1-3 are prepared so that the file system can be accessed from the AP 1-2 including the API. This API processing program uses a table 1-4 for managing the entire file system.

Here, the API processing program 1-3 will be described with reference to FIG. The API processing program includes a path name analysis unit 2-1 for analyzing a path name of a file to be accessed specified in the API, a directory search unit 2-2 for searching under which directory a target file is located, and adding a directory. Operating means 2-3 for updating an internal table when directory information is changed due to deletion or deletion, etc., and file system type determining means 2 for determining whether a file is a plain file or an existing various file system from information of the table. -4,
Since the actual file access method differs depending on the file system, the file system access means 2-5 and 2-6 corresponding to each file system, and the file information search means 2 for searching a table storing information of files under a directory. -7 is included. These means make the present invention feasible by using the management tables 1-4.

Next, the details of the table 1-4 for managing the file system will be described with reference to FIG. The hierarchical directory compatible file system manages volume information, device information, and the like relating to a file system having a non-hierarchical directory structure, which are necessary when actually accessing a file, using the file system management table 3-1. This is because the traditional non-hierarchical directory structure files are
This table is indispensable because there are various other formats and access methods are generally different from each other.

Information on the directory, such as the directory name and the parent-child relationship of the directory, is managed by the directory management table 3-2. When performing a directory operation from the API, the contents of the data in this table are updated. It also points to file information immediately below the directory and is used to search for files containing directory names.

File protection information, file size,
In a file system with a non-hierarchical directory structure,
Information for mapping an actual file is managed by the file management table 3-3. If compatibility with the conventional file system is not taken into consideration, the contents of the actual file may be stored in this hierarchical directory compatible file system. Need to store information for mapping.

Next, with respect to the operation of the present embodiment, FIGS. 4 and 5 show an example in which a directory is created from an AP and an example in which data is written from an AP to a file containing a directory name.
I will explain using. First, an example of creating a directory from an AP will be described. An API (mkdir ()) for creating a directory is called from the AP (4-
1), the hierarchical directory API processing program analyzes the specified directory name by the path name analysis means 2-1 and searches the directory management table for information on the corresponding directory by the directory search means 2-2 (4). -2).

It is determined whether the directory already exists (4-3). If the directory exists, an error (4-6) occurs, and
Do not create directories. If the specified directory does not exist, the directory operation table 2-3 adds directory information to the directory management table (4).
-5), the creation of the directory is completed (4-6).

Next, an example of writing data from an AP to a file including a directory name will be described. When an API (write ()) for writing data is called from the AP (5-1), the hierarchical directory API processing program analyzes the specified directory name by the path name analysis means 2-1 as in the directory creation processing. Then, the directory search means 2-2 searches the directory management table for information on the corresponding directory (5-
2). Here, there are error cases such as the directory does not exist, but the description is omitted because it is not the main subject. When the directory information is found, the corresponding file management table is searched from the directory information by the file information search means 2-7 (5-3). Since the data writing process differs depending on the type of the file system to which the corresponding file belongs,
The file type is determined by the file system determination means 2-4 according to the attribute of the file system management table (5-4). If the data set is a conventional data set, the file system access unit 2-5 writes the data in the conventional data set in the conventional data storage format using the information on the file system stored in the file system management table ( 5-5). If the type of the file is a plain file, the information about the file system stored in the file system management table is used.
6, data is written in a plain file processing and data storage format. When a series of processing is completed, data writing is completed (5-6). in this way. By allocating the data structure and processing method according to the type of file, while guaranteeing access to the conventional file system,
It also allows access to a file system with a hierarchical directory structure.

Although the directory can be manipulated by the method described above, a file system having a hierarchical directory structure generally uses plain files, and thus an AP using a file system having a hierarchical file structure. In order for this to work without modification, this point also needs to be considered. This will be described with reference to FIG. In a conventional file system such as a sequential data set or a divided data set, unlike a plain file, a method in which a user specifies a file size for each file in advance is adopted 6-4. The data storage format is a format for storing one character string for each record 6-3. However, in the case of a plain file, the file size does not need to be specified by the user, and the data is stored in a format in which a character string delimiter such as a line feed code is stored in a record, and data is stored in one record. 6-1. The difference in the data storage format can be solved by the difference between the file system access means 2-5 and 2-6. However, if 1 file = 1 data set (conventional 1 file), the file size needs to be defined in advance. , AP does not need remodeling,
The user needs to define the file size in advance. In order to solve this problem, a plurality of files = 1 data set is set so that the file size can be freely managed 6-2. Since the processing program manages the file size, the user does not need to specify the file size for each file.

[0021]

According to the present invention, when a program including an API for operating a hierarchical directory operating on a computer system having a hierarchical directory is ported to a computer having no hierarchical directory, a portion for operating the hierarchical directory which has been conventionally required. No program change is required.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing an embodiment of the present invention.

FIG. 2 is a functional configuration diagram of a hierarchical directory API processing program according to the embodiment of the present invention.

FIG. 3 is a table diagram of the embodiment of the present invention.

FIG. 4 is a diagram showing a table structure according to the embodiment of the present invention.

FIG. 5 is a diagram showing the contents of data according to the embodiment of the present invention.

FIG. 6 is a diagram showing the difference between the data storage format of a plain file and that of a conventional data.

FIG. 7 is a diagram showing a conventional method.

[Explanation of symbols]

1-1: Computer system without hierarchical directory,
1-2.. A including API for operating hierarchical directory
P, 1-3 ... an API processing program using a hierarchical directory, 1-4 ... a file system management table,
1-5: Hierarchical directory compatible file system, 1-
6 ... Segment data set, 1-7 ... Order data set, 1-
8 Plain file, 2-1, 2-2, 2-3, 2-
4.2-2-5 ・ 2-6 ・ 2-7 ... Hierarchical directory API
Means included in the processing program, 3-1: File system management table, 3-2: Directory management table, 3-3: File management table, 6-1: Data storage format of plane file, 6-2: Variable file size 6-3: conventional data storage format, 6-4: fixed file size file system,
7-1: Computer system having hierarchical directory, 7-
2 ... AP including API for operating hierarchical directory, 7
-3: an API processing program using a hierarchical directory, 7-4: a hierarchical directory structure file system,
7-5: Computer system without hierarchical directory
7-6 AP that operates hierarchical directory requiring remodeling
AP including I, 7-7... Sequential data set, 7-8.

Claims (3)

[Claims] In a computer system having a first file system having a non-hierarchical directory structure and having no hierarchical directory, a second file system having a hierarchical directory mapped to the first file system and a hierarchical directory are accessed. Processing table for managing mapping information and device information between the second file system and the file of the first file system, and the first file system through the mapping information of the second file system from the application program. A file system access method for determining the file type of the file in the first file system when accessing the file, and accessing the file using an access method and a data storage format according to the file type. 2. The method according to claim 1, wherein a plurality of files of the first file system are stored in one of the first file systems.
A file system access method with a plain file stored in a file. 3. The method according to claim 2, wherein when the application program accesses the file of the first file system through the mapping information of the second file system, the file type including the file of the first file system and the plain file is changed. A file system access method for determining and accessing a file or a plain file of a first file system in an access method and a data storage format according to a file type.