JPH0559459B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is suitably used in a system including a plurality of input/output means, such as a computer system, and dynamically controls the input/output means specified by an execution program. This invention relates to a method for changing input/output means.

PRIOR ART In general, in a computer system (for example, a system with multiple printers) connected to a plurality of input/output devices, an operating system (hereinafter referred to as (abbreviated as "OS") is used, and various execution programs are started according to the specifications of this OS.

Conventionally, in such a computer system, when printing out data is required to create various execution programs, one of the multiple printing devices installed in the system is used. Which printing device should be used to perform printout was described in each execution program. When an execution program with such a description is started, the OS allocates the printing device specified by the execution program for printing out the data of the execution program and performs printing operations. was.

Problems to be Solved by the Invention In the prior art as described above, when each execution program is created, the execution program is specified by the OS and system configuration on which the execution program is started.
It is necessary to specify an input/output device such as a printing device, which creates a great burden in creating each execution program. In addition, as mentioned above, the printing device specified in each execution program is unique to that execution program, and the data printed out by each execution program depends on the usage status of each input/output device of the system. It was not possible to switch the printing device used. Therefore, there has been a limit to the improvement in convenience of such a system.

An object of the present invention is to solve the above-mentioned problems, eliminate the need to pay attention to the configuration of input/output means of a system in which the executable program is used when creating an executable program, and to Input/output means assigned to the program,
It is an object of the present invention to provide a method for changing input/output means that allows switching between a plurality of means.

Means for Solving the Problems The present invention comprises: a control means 1; a storage means 5 in which an execution program that defines the operation of the control means 1 is stored; and a plurality of inputs whose operations are controlled by the control means 1. /output means 2 and 3, and the storage means 5 stores a logical name 14 that is specified by the execution program and defines each input/output means 2 and 3;
A storage area 11 is provided in which a device number 15 uniquely given to each input/output means 2, 3 and a file name 16 associated with a logical name are stored, and the input/output means 2, 3 are stored according to the logical name. 3 is started, the storage area 12 is searched, and if a file name corresponding to the logical name is assigned, the input/output means 2 having the device number 16 corresponding to the file name is activated. , 3, prepare an instruction for changing the contents of this storage area 11, and execute the instruction without changing the program contents of the execution program. After changing and registering a new file name corresponding to a logical name, when an execution program with the logical name is started, the device number of the input/output means specified by this logical name will be changed. This is a method for changing input/output means characterized by the following.

Operation The storage means according to the present invention has a logical name 1 which is instructed by the execution program and which designates each input/output means.
4, the device number 15, and the file name 16 are associated with each other. Prior to starting the execution program, read/write is performed on this storage area.
It is possible to easily register a new file name that corresponds to the logical name in the instruction without writing and changing the program contents of the executable program, and it is possible to easily register a new file name that corresponds to the logical name in the instruction. You can create executable programs without paying anything. Furthermore, if reading/writing is performed on the storage area as described above before starting the execution program, the input/output means for outputting data of the execution program can be arbitrarily set as necessary. Can be changed.

Embodiment FIG. 1 is a block diagram showing the configuration of, for example, an electronic computer system according to an embodiment of the present invention. 1st
The configuration of this embodiment will be explained with reference to the drawings. This computer system includes a central processing unit (hereinafter abbreviated as CPU) 1, a control console (including a keyboard and a cathode ray tube (CRT)) 2 that controls the entire computer system, and general functions of such a system. For example, a plurality of keyboards 3c that can be used by users, printing devices such as various printers 3a, and a CRT (cathode ray tube) 3.
b, etc. are connected to a common line 4. If the above-mentioned reference marks 3a, 3b, and 3c are collectively represented by reference mark 3, the above-mentioned control console 2, keyboard 3c, various printers 3a, and CRT 3d are:
Input/output means 2 and 3 are configured.

On the other hand, connected to this line 4 is an internal memory 5 which is a storage means that can be immediately accessed by the CPU 1. The internal memory 5 is composed of random access memory (RAM), read-only memory (ROM), and the like, and includes an execution program storage area 6 and an OS storage area 7.
The OS stored in the OS storage area 7 includes a printer management service module (hereinafter referred to as PMS) 8 that manages the allocation status of printers in this system, and is also managed by this PMS 8. A device allocation table 9 including a print control table, which will be described later, is provided. Connected to the line 4 is an external storage device 10 comprising a floppy disk and a disk drive device constituting storage means.

Figure 2 shows the device allocation table 9 shown in Figure 1.
3 is a diagram showing the configuration of the printer control table 11 of the device allocation table 9. FIG. With reference to FIGS. 2 and 3,
The configurations of the device allocation table 9 and the printer control table 11 will be explained. As shown in FIG. 1, the device allocation table 9 includes a printer control table 11 in which the allocation states of a plurality of printers 3a are set in relation to respective execution programs, a similar CRT terminal control table 12, and a similar CRT terminal control table 12. Keyboard control table 17
and a console control table 13 in which the allocation status of the control console 2 is described. Also each table 13,1
2, 11, 16, ... are device numbers "0", "1", "2", "3" indicating the types of input/output devices such as the control console 2, CRT terminal 3b, printer 3a, and keyboard 3c, respectively. ”,… are given.

As shown in FIG. 3, the printer control table 11 includes logical names "PRT00" and
A logical name storage area 14 in which "PRT01", "PRT02", etc. are stored, and a logical name storage area 14 that is uniquely given to, for example, four printers 3a provided in the computer system shown in the first figure, and is used to distinguish each printer 3a. Printer device numbers used “1”, “2”, “3”,
A device number storage area 15 in which "4" is stored, a file name "/dev/prt0" that has a unique correspondence with each printer device number, is associated with the logical name, and has the following format, for example, "/dev/prt1",
... is stored in the file name storage area 16. When the computer system shown in FIG. 1 is started up, the contents of the printer control table 11 are initialized in advance as shown in FIG. 3.

FIG. 4 is a flowchart illustrating the processing performed when an instruction to perform printout is issued when one execution program is started in the electronic computer system shown in FIG. With reference to Figures 1 to 4,
The processing in this case will be explained. In the execution program in the computer system in this embodiment, input/output devices are specified in the third
This is done using one of the logical names shown in FIG.

Therefore, when an execution program that specifies an input/output device using such a logical name is started, in step n1 of FIG. 4, the CPU 1 searches the device allocation table 9 shown in FIG. 2 for the logical name. . Next, in step n2,
It is determined whether the file name shown in FIG. 3 that corresponds to the logical name is set in this device allocation table 9. If the determination is positive, the process moves to step n3, where an input having a file name (for example, the above-mentioned "/dev/prt0") and a corresponding printer device number ("1") for the logical name (for example, "PRT00") is entered. /Enables sending and receiving of information to and from an output device.

If the judgment in step n2 is negative,
This means that the file name corresponding to the logical name has not been assigned, and in this case the process will skip to step 1.
Moving on to n4, for the initialized file name (for example, logical name "PRT00") in the device allocation table 9 of FIG. 3, the file name "/dev/
prt0") enables the exchange of information with devices that support it. The input/output processing in the execution program after steps n3 and n4 is performed by the input/processing device corresponding to the file name set in each step.

FIG. 5 is a flowchart illustrating an operation for changing the contents of the printer control table 11 shown in FIG. 3, for example. In this embodiment, in order to execute such an operation, for example, an instruction "passign" is prepared in the electronic computer system shown in the first diagram. This instruction is used according to the format below.

"passign PRT00 /dev/prti" (i = 0, 1, 2, ...) The execution of this command "passign" does not change the program contents of the executing program that attempts to change the input/output device. executed independently.

At step m1 in FIG. 5, for example, the command "passign PRT00 /dev/prt1" is input and executed. In step m2, the CTU 1 searches the device allocation table 9 for the logical name "PRT00" in the above instruction. step
In m3, it is determined whether a file name specifying an input/output device is assigned to the logical name "PRT00" in the device assignment table 9. If this judgment is positive (for example, the third
As shown in FIG. 1, it is assumed that the file name "/dev/prt0" is assigned to the logical name "PRT00") The process moves to step m4, where printer control table 1 in device assignment table 9 is assigned.
The file name assigned in 1 “/
dev/prt0".

Next, the file name "/dev/prt1" newly assigned to the logical name "PRT00" is newly registered in the file name storage area 16 by the command "passign" given in the above format.

Through the series of processes described above, the printer control table 11 changes from the state shown in FIG. 1 to the state shown in FIG.
The state is changed to the one shown. Therefore, after this, when the execution program having the logical name "PRT00" is started in the computer system shown in the first figure, for example, the printer 3a of the output means 3 specified by the logical name "PRT00" is The device number "1" shown in FIG. 1 is changed to the device number "2".

If the judgment in step m3 is negative, the file name storage area 16 corresponding to the logical name "PRT00" is blank, so the process moves to step m5 without going through step m4.
The process of step m5 may be executed for the blank area. As described above, in this embodiment, by preparing the instruction "passign" shown in the above format, the input specified by the execution program can be processed without changing the contents of each execution program. /Output device can be changed arbitrarily.

Effects As described above, according to the present invention, the present invention includes a control means, a storage means in which an execution program that defines the operation of the control means is stored, and a plurality of input/output means for causing the control means to control the operation. In the system, the storage means includes logic 14 for specifying each input/output means instructed by an execution program, a storage area 11 for storing a device number 15, and a file name 16 in association with each other. . Further, reading/writing is performed to/from this storage area prior to starting the execution program.

Therefore, in the execution program, when instructing the input/output means, an instruction for changing the contents of the storage area 11 is prepared, and the execution program is executed without changing the program contents, and the logic in the instruction is All you have to do is register a new file name that corresponds to the name. In this way, the burden of input/output operations on the execution program can be reduced, and the input/output means employed in a given execution program can be changed as necessary, so that such input/output operations can be reduced. The convenience of the system including the output means is greatly improved.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of a computer system according to an embodiment of the present invention, FIG. 2 is a diagram showing the configuration of a device allocation table 9, FIG. 3 is a diagram showing the configuration of a printer control table 11, and FIG. FIG. 4 is a flowchart illustrating operations when starting an execution program and performing input/output, and FIG. 5 is a flowchart illustrating operations for changing the printer control table 11 in one embodiment of the present invention. 1...CPU, 2...Input means, 3a...Printer, 5...Internal memory, 8...PMS, 9...
Device allocation table, 11... Printer control table, 14... Logical name storage area, 15... Device number storage area, 16... File name storage area.

Claims (1)

[Claims] A control means 1; a storage means 5 in which an execution program that defines the operation of the control means 1 is stored; and a plurality of input/output means 2, 3 whose operations are controlled by the control means 1. The storage means 5 includes a logical name 14 that is specified by the execution program and defines each input/output means 2, 3;
A storage area 11 is provided in which a device number 15 uniquely given to each input/output means 2, 3 and a file name 16 associated with a logical name are stored, and the input/output means 2, 3 are stored according to the logical name. 3 is started, the storage area 12 is searched, and if a file name corresponding to the logical name is assigned, the input/output means 2 having the device number 16 corresponding to the file name is activated. , 3, prepare an instruction for changing the contents of this storage area 11, and execute the instruction without changing the program contents of the execution program. After changing and registering a new file name corresponding to a logical name, when an execution program with the logical name is started, the device number of the input/output means specified by this logical name will be changed. An input/output means changing method characterized by: