JPH0922375A - File management method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the omission of data from occurring by managing the final recording unit of a file as an invalid recording unit when the size of the file is not the integral multiple of a prescribed recording unit. SOLUTION: Whether or not all the final recording unit of the file to be added is valid, is checked. In this case, since the file A (2) is to be added to the file A (1), the data of the final recording track (m) of the A (1) are checked. The judgement is performed depending on whether or not a file capacity is the integral multiple of a track capacity. That is, it is judged that all the data of the final recording track (m) are valid in the case of being the integral multiple and that invalid data are present in the track (m) in the case of not being the integral multiple. In this case, since an invalid data part 204 is present in the final recording track (m), NO is judged and the valid data part 306 of the final recording track (m) of the file A (1) to be added is read onto the butter memory of a host computer. Then, addition is performed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a file management method for data files on an information recording medium, and more particularly to a file management method for adding data to a file on an information recording medium that cannot be erased and rewritten.

[0002]

2. Description of the Related Art Conventionally, as an information recording medium, a floppy disk for recording / reproducing by using magnetism, an optical information recording medium for recording / reproducing by using light, etc. are known. The optical information recording medium has a disc shape,
Various types such as cards and tapes are known. Among such optical information recording media, a card-shaped optical information recording medium (hereinafter, referred to as an optical card) is expected to be in great demand as a relatively large-capacity information recording medium that is small and lightweight and convenient to carry. Has been. Information recording media are erasable and rewritable depending on the characteristics of the media, but optical cards are generally erasable and non-erasable, which is an advantage that rewriting is not possible in the medical field. It is expected to be applied in the following fields.

Generally, in order to manage a large amount of data on such an information recording medium, auxiliary data for managing data block by block, so-called directory is used. The directory is usually composed of file information such as the file name, file length and head data track number of the file managed by the directory, and this is written in a part of the recording medium to manage the file of the data section. The above optical cards, especially the non-erasable optical cards, have a large recording capacity even if they are about the size of a credit card. Requires a method of managing information using a directory.

FIG. 7 is a schematic plan view showing an example of an optical card. As shown in FIG. 7, in the recording area of the optical card, a data section 10 (101, 10) including data tracks is formed.
2, ..., 10n) and the directory unit 20 (201,
202, ..., 20 m). When recording data in the data section 10 above the optical card, E
When the directory information, which is the data management information, is recorded in the directory portion 20 below the optical card 1, the data is written in the D direction.

On the other hand, in order to manage data as a file, in addition to directory information which is identification information for distinguishing a file from other files, which track of the information recording medium, or which track the file has, may be determined. Starting from a sector that is divided into units, or a cluster that is a management unit in which a plurality of sectors are grouped together, it is arranged in which track (hereinafter, the minimum recording unit and the management unit is one track) and in what order. Information indicating whether the file is stored, that is, map information for indicating file storage information is required. Generally, this map information is called a file allocation table (FAT).

FIG. 8 is a diagram for explaining the concept of such FAT. In FIG. 8, the FAT 30 has areas 1, 2, ..., Which correspond to the data tracks on the optical card.
N (generally around 2500) is prepared, and a track number in which information subsequent to the information recorded in that track is recorded is recorded in each area. For example, FIG. 8 shows that the file starting in the area 1 continues to the area 2 and the area 4, and the file starting to the area 3 continues to the area 5, the area 6 and the area 7. In FIG. 8, "FF" in the area indicates that the file does not continue, that is, the last track of the file, and "0" indicates that track. Indicates that it is an unused (no data recorded) track. By using the FAT and the directory together, the identification information such as the file name and the head track number can be known from the directory, and the stored information can be known from the FAT, so that efficient file management can be performed.

By the way, a FAT managed in track units
In order to record FAT on an optical card,
Assuming that the maximum track number is 2500, 12 bits are required for one area in FIG. 8 and 2500 areas are required. Therefore, 12 bits × 2500 = 30000 bits =
A storage capacity of 3750 bytes is required. This is about 7.3 when the capacity of one track is 512 bytes.
It is equivalent to the capacity of the track.

If the recording medium is erasable and rewritable, FAT
The area may be prepared in a specific area on the medium, and when there is a change in the stored information due to a new file being recorded or the file being updated, the area may be rewritten with the latest information. However, with a non-erasable rewritable medium such as an optical card, a new FA is added whenever the stored information changes.
It is necessary to additionally record T, and for example, each time a new file is added, the information recording capacity of about 8 tracks must be used as the FAT as described above. This means that if the total number of tracks is 2500, for example,
/ 8 = about 312, which means that even if all tracks are set to FAT, only about 300 changes in stored information can be tolerated.

Actually, since the data and the directory are recorded, the number of tracks applied to the FAT is further reduced, but on the other hand, for example, several times at a time (from inserting the optical card into the recording / reproducing device to ejecting it). Even if there is a change in the stored information, the FAT needs to be recorded only once before the ejection of the optical card, so a value of about 300 times is only a guide, but it does not deviate significantly from this value. As described above, in the related art, when the FAT is recorded on the optical card that cannot be erased and rewritten for file management, there is a problem that the information capacity of the optical card cannot be effectively used.

Such a problem does not allow random recording of data on tracks, but only sequential recording, that is, recording of a new file is always performed from the track next to the last recording track at that time. Starting, the data can be resolved by sequentially recording on subsequent tracks. In this case, the first track number and the size of the file (the number of used tracks) can be known from the directory information, and the continuation of information is always in the next track.
The FAT can be constructed from the directory information without recording the FAT on the optical card.

On the other hand, the applicant of the present application has disclosed a method of using an append flag as a method of adding (appending) data to a file in an information recording medium which cannot be erased and rewritten in Japanese Patent Laid-Open No. 1-258288. That is, a flag (append flag) indicating addition of file data is provided in the directory, and when data is added to an existing file, the data to be added is recorded as another file,
Additional data file (partial file) in the directory section
In the directory for managing the files, by incrementing and recording the append flag, a file having the same file name but different append flags is considered as one file divided and recorded in the order of the append flag.

FIG. 9 is a diagram for explaining the addition of data to a file using such an append flag, and schematically shows the data part. In FIG. 9, A,
B indicates the file name, and the numerical value in parentheses indicates the append flag. For example, 201 indicates the first data (partial file) of the file A. Similarly, 202 indicates the first data of the file B, and 203 indicates the next data of the file A, that is, the data added to A (1). Although not shown in FIG. 9, a directory managing each partial file is recorded in the directory section. A (1) is from track 1 to m, B is
(1) occupies tracks m + 1 to n-1 and A (2) occupies tracks m to k.

If data is recorded on a track-by-track basis, the file size is not always an integral multiple of the capacity of one track. For example, as shown in tracks m and k in FIG. Generally, invalid data sections 204 and 205 are present in the last track of each file. When the files A (1) and A (2) are considered as one continuous logical file A, the logical file structure is such that the first part of the file A (2) is the invalid data section 204. Should exist, and that conversion needs to be done.

However, for example, when reading data byte by byte, it is necessary to read the first byte of track n after the last valid byte of track m, which causes a problem of complicated processing. Further, since data is reproduced for each track, the time required for reproducing one track is the same even if there is no invalid data portion in one track, and the more the number of additions, the more wasteful it is. There is also a problem that the time increases and it takes time to reproduce. This problem is especially due to the fact that the amount of added files and added data is a fraction of the amount of data within one track.
And it is remarkable when small. For example, if the file size is ⅕ of one track, one track is required for one addition, so if four times addition is performed, five tracks including the first file must be reproduced. Actually, the contents of all files corresponding to the storage capacity of one track (1/5 × 5 = 1) cannot be reproduced.

Therefore, the applicant of the present application has disclosed a file management method that solves this problem in Japanese Patent Application Laid-Open No. 4-141867. In this file management method, data is sequentially recorded in continuous tracks in the data section, a flag indicating addition of file data is provided in the directory for managing file data, and the flag is added when additional data is recorded in an existing file. Data is sequentially recorded as a separate file in the data section, and a directory for managing additional file data is recorded in the directory section by incrementing and recording the flag. In the file management method of managing as one file dividedly recorded in numerical order, when the additional data is recorded, when the last recording track of the file to which data is added has an invalid data part,
The data recorded on the last recording track is read into a buffer memory, data to be newly added is added to the rear portion of the read data and sequentially recorded, and at the time of reproduction, a file having the same file name but different flag The last recorded track of a file whose flag is other than the maximum value is managed as an invalid track.

[0016]

Now, as a result of applying the recording process of the above file management method,
Consider a case where each file data is arranged as shown in FIG. 3C when the data part is simulated. FIG.
In (c), A and B indicate the file name, and the numerical value in parentheses indicates the append flag. For example, 201
Is the first data (partial file) of file A
2 is the first partial file of file B, 308, 30
Reference numeral 9 indicates the second and third partial files of the file A. That is, the file A is A (1), A (2), A
It consists of three partial files in (3). A (1)
Are recorded on tracks 1 to m, and 204 of the last recording track m is invalid data and 306 is valid data.

A (2) is track n to track j.
-1 of the first track n is placed at -1, and the first track n of 307 is 3 in the last track m of A (1).
It is a copy of 06. Furthermore, the final track j-1
Are all valid data, and there is no invalid data in A (2). A (3) is arranged in the track j to the track k-1, and the final track k-1 has an invalid section 311.
Since the last recording track j-1 of the partial file A (2) immediately before A (3) is all valid data, that data is not copied to the head track of A (3). On the other hand, B (1) of the file B is a single file, is arranged in the tracks m + 1 to n-1, and valid data is recorded in all the tracks.

Here, when each file data is arranged as shown in FIG. 3C, the processing at the time of reproduction of the above file management method is applied as follows. That is,
Since A (3) is a partial file having the maximum value of the append flag of the file A, its final recording unit, that is, the final recording track k-1 cannot be considered as an invalid recording unit. On the other hand, since the append flag of A (1) and A (2) is not the maximum value, the final recording unit thereof, that is, track m and track j-1 is managed as an invalid recording unit. In this case, since track 204 has invalid data from the beginning and 306 has been copied as 307 in A (2), there is no problem in managing track m as invalid data.

However, although track j-1 is originally all valid data (that is, not copied to the first track of A (3)), it is managed as invalid data and A Part of the data in (2) will be lost. That is, according to the conventional file management method, when all the final recording units of the final file before data addition (A (2) in this example) are valid data, data addition (A (3 in this example) () Is added), there is a problem that the data recorded in the final recording unit of the partial file before the addition is lost during the reproduction.

In view of the above-mentioned conventional problems, the present invention provides a file management method capable of preventing data loss and easily reproducing data without requiring any complicated processing. It is intended.

[0021]

It is an object of the present invention to use an existing file by using a recording medium having a data section for recording file data and a directory section for recording a directory for managing the file data. When additionally recording data, the data to be added is recorded in the data section as a file different from the existing file, and a directory for managing the additional file data is added to indicate the addition of the file data included in the directory. By incrementing the flag and recording the same in the directory section, files having the same name but different flags are managed as one file divided and recorded in the order of the flag number. If there is invalid data in the final recording unit, the final recording The effective data of the order is read into the storage means, and the data to be added is stored after the effective data of the storage means and sequentially recorded in the data part, and when reproducing the data, the file name is the same name and the flag is the maximum. When the file is a value other than the value and the size of the file is not an integral multiple of the predetermined recording unit, the final recording unit of the file is managed as an invalid recording unit, which is achieved by the file management method.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below in detail with reference to the drawings. First, FIG. 2 is a flowchart showing a data recording process to a file by the file management method of the present invention. 3 shows a file in the data section 10 of the optical card 1 and FIG. 4 shows a directory in the directory section 20. In the state shown in FIGS. 3A and 4A, a new file A (2) is created. The process of additionally recording will be described with reference to FIG. In FIG. 2, first, when the optical card 1 of FIG. 7 is set in the information recording / reproducing device (not shown), it is checked whether all the final recording units of the file to be added are valid (S201). Here, FIG.
Since the file A (2) is added to the file A (1) of (a), the data of the final recording track m of A (1) is checked. The determination of this check is based on the file A recorded in the directory section 20 as shown in FIG.
It is determined whether the file capacity in the directory 301 for managing (1) is an integral multiple of the track capacity.
That is, if it is an integral multiple, it is determined that all data on the final recording track m is valid, and if it is not an integral multiple, invalid data exists on the track m.

In this example, since the invalid data section 204 exists in the last recording track m as shown in FIG.
The file A (1) to be added is judged as NO in 01 and is added.
The valid data portion 306 of the final recording track m of the above is read into the buffer memory of the host computer (S20).
2). The host computer is a host controller of the information recording / reproducing apparatus, and the data in the buffer memory of the host computer is shown in FIG. 401 is the last recording track m of the file A (1) read on the buffer memory
Is valid data of. Next, as shown in FIG. 5, the data 402 to be added to the data 401 read on the buffer memory is added after the data 401 (S20).
3). The data to be recorded is prepared in the buffer memory as described above, and then the data in the buffer memory is sequentially recorded in the data section 10 of the optical card 1 for each track (S).
204). In this embodiment, the file A (2) is the file shown in FIG.
Tracks n to j-1 are recorded as shown in FIG.

Here, the data 401 on the buffer memory
Is recorded on the track n as data 307 as shown in FIG. 3B, and the valid data of the last recording track m of the file A (1) to be added is copied as the data 307 to the first track n of the file A (2). To be done. Further, the data 402 on the buffer memory 400 is recorded as the data 308. Finally, file A as shown in FIG.
The directory 303 for managing (2) is recorded in the directory section 20 (S205). In this case, the append flag in the directory information is recorded as "2" as 1 increment because the maximum append flag value of the directory that manages the file having the file name A up to that point is "1".

Next, processing for additionally recording the file A (3) in the file of FIG. 3 (b) will be described. In this case, the capacity of the added file A (2) is an integral multiple of the capacity of one track, as is apparent from FIG. In this example, in S201, the file A
All the data of the final recording track j-1 of (2) are judged to be valid data. Therefore, in this case, file A
Since it is useless to copy the data of the final recording track j-1 of (2), the data 403 to be added to the buffer memory is read without copying as shown in FIG. 5 (S206). The rest is the same as the above description, and the data 403 on the buffer memory is stored in the data section 10 of the optical card 1 as 1
It is sequentially recorded for each track (204). here,
As shown in FIG. 3C, data is recorded from track j to track k-1. Finally, file A as shown in FIG.
The directory 304 for managing (3) is recorded, and the process ends (S205). Note that the append flag in the directory information is incremented by 1 and recorded as "3" because the maximum append flag value of the directory that manages the file with the file name A up to that point is "2".

Next, a process for creating a FAT from directory information when reproducing information will be described with reference to FIGS. 1 and 6. FIG. 1 is a flowchart showing the flow of processing when creating a FAT from directory information, and FIG. 6 is an explanatory diagram showing the contents of the FAT created by that processing. First, when the optical card 1 is inserted into an information recording / reproducing apparatus (not shown), all directories in the directory section 20 of the optical card 1 are read and stored in a buffer memory (not shown) of the host computer (step 101). ). In this case, file A (1), file B as shown in FIG.
The directories 301 to 304 for managing (1), file A (2), and file A (3) are read onto the buffer memory.

Next, one directory is read from the buffer memory (step 102), and it is determined whether the file corresponding to that directory is the end (S103). At this time, since the directory has just been read, it is determined that the end of the file has not been reached, and the FAT is created based on that directory. In this case, the first track number (track 1 in this case) in the directory information and the file capacity are known,
The capacity of one track is fixed, so you can see the final track. Therefore, first, the next track number 2 is stored in the FAT corresponding area 1 (S104), and then the next track number 3 is stored in the next corresponding area 2 of the FAT (S10).
5). By repeating the processing of S103 to S105 in this manner, the FAT is created as shown in FIG. Then, when it is determined in S103 that the file is at the end, the area m corresponding to the final track as shown in FIG.
The FF indicating the end of the file is stored in (S10).
6).

Next, in S107, it is checked whether the file managed by the directory is an additional file, that is, whether the append flag is "1" indicating the first file. In this case, the append flag is "1" and it is not an additional file, so the routine proceeds to step 113, where it is checked whether or not there is a directory on the buffer memory that has not been read. If the directory exists, the process returns to step 102, and if it does not exist, the process proceeds to step 114. In this case, since there is a directory that has not been read yet, the process returns to step 102 and the same process is performed on the next directory. At this time, the directory 302 is read out to the buffer memory next, and the file B managed by the directory 302 is read.
Since (1) is not an additional file like the file A (1), its processing is the same as the processing relating to the directory 301 described above. FIG. 6B shows the state of the FAT after the processing regarding the directory 302 is completed.

Subsequently, the next directory 303 is read out, and similarly, FAT is also based on the directory information.
Is updated. In this case, the file name is A which is the same as that previously reproduced, and the append flag is "2", so it can be seen that this is the information added to the file A (1) in step 107. Therefore, at this time, the directory that manages the added file, that is, the file A
The directory 301 of (1) is read again (step 108), and it is checked whether the file capacity is an integral multiple of the track capacity (step 109). If the result of this check is that it is an integer multiple, that is, if there is no invalid data in the partial file managed by that directory, the process proceeds to step 112. If it is not an integer multiple, that is, invalid data is found in the partial file managed by that directory. If there is, go to step 110.

Here, in the file management method of the present embodiment, when data is added to the file as described above, if the final recording unit of the file to be added has an invalid data section, the last recording unit is valid. The data is copied in the first recording unit of the added file. Therefore,
In step 110, the final track of the file to be added, in this example, the area m of the FAT corresponding to the final recording track m of the file A (1) is rewritten to "FE" indicating that it is an invalid track. In step 111, the track m immediately before the last track
After rewriting the area m-1 of the FAT corresponding to -1 to the head track n of the file A (2) to be added, the processing from step 113 onward is performed. Directory 303
FIG. 6 shows the state of the FAT at the time when the processing relating to FIG.
(C).

Then, the next directory 304 is read into the buffer memory and the same processing is performed. In this case, since it is found in step 107 that the file is an additional file, similar processing is performed in steps 108 and 109.
That is, in step 109, since the file size of A (2) is an integral multiple of the track capacity, the process proceeds to step 112, and the final recording unit of the file to be added, in this example the final track j- of file A (2). FA equivalent to 1
The area j-1 of T is rewritten to j which is the head track of the file A (3) to be added, and the process proceeds to step 113. FA at the time when the processing related to the directory 304 is completed
T is shown in FIG. At this point, there is no unread directory in the buffer memory, so in step 114, "00" indicating unused is recorded in all the remaining FATs, and the creation of the FAT ends. The final FAT is shown in FIG.

Next, the operation of reproducing the data of the optical card 1 by using the FAT thus created will be described. First, the file A is physically divided into three, but is logically one file. When playing back this file A, track 1 is followed according to FAT.
To the track m-1 are sequentially reproduced. Then FA
In the area m-1 of T, there is information indicating that the following information of the file is recorded in the track n, so that the track n is reproduced without reproducing the track m, and then the track n + 1 is sequentially recorded. Plays up to j-1.
In the area j-1 of the FAT, there is information that the following information of the file is recorded on the track j, and therefore, from the track j to the track k-1, "FF" indicating the end of the file is displayed in the FAT. Is continuously reproduced up to the track on which is recorded.

Here, track m is at the beginning of track n.
Since the valid data 306 recorded in (1) is copied as the data 307, it is possible to reproduce the continuously added information without loss of data. Moreover, since all the data on each track are only valid data, and a track in which valid data and invalid data are mixed (for example, track m) is not accessed, complicated processing is performed considering how valid the data of one track is. It is possible to sequentially reproduce the information simply according to the information indicated by the FAT. Also, like the conventional file management method, when the file size of the partial file is an integral multiple of the track capacity, that is, when the partial file has no invalid data part,
The valid data recorded in the final recording unit (track j-1 of the file A (2) in this example) is managed as invalid data, and there is no problem of data loss.

Further, the present embodiment has an advantage that the information of the last recorded track of the file can be updated when the last track of the file has an invalid data portion. That is,
If the last recorded track has an invalid data section, the data of the last track is read once into the buffer memory as described above, so if you update that data in the memory at this point, the updated data will be added to the additional file. It is possible to record at the beginning of the, and it is possible to logically update the data. If the size of the file is (capacity of one track-1 byte), all data can be updated. In this case, as directory information, there is a directory that manages files before update, and there are directories with the same file name but different append flags for the number of updates, and all files with the same name have been added. Although it is recognized as one file, the mark "FE" indicating an invalid track is recorded in the area corresponding to the file other than the maximum append flag number of FAT. As a result, the last added (actually updated) file Only the data of can be reproduced.

If the capacity of the file to be added and the data to be added is a small fraction of N (N is an integer) of the data capacity within 1 track, the total file capacity is 1 track by adding N-1 times. It is not necessary to play N tracks as before until the capacity of is reached, and the data of all files can be obtained by playing only one track in which the last additional file is recorded based on the FAT information. However, it is not necessary to reproduce all the added M tracks as in the conventional case, even if the tracks are added by M times (M is an integer of M> N) times. That is, all the tracks that have become valid data by the addition (the number of tracks is
When int () is an integer part of the value in parentheses, it can be represented by int (M / N)) and only the last track of the file is reproduced (therefore, the number of reproduced tracks is int (M / N)). / N) +1, which is obviously smaller than M), and has the advantage that the number of reproduction tracks is small and the time required for reproduction can be shortened.

In the above embodiments, the minimum recording unit and the management unit are one track.
This is not limited to tracks, but may be sectors or clusters. Further, in the embodiment, the case where two additions are made has been described as an example, but when there are more additions,
The same process may be repeated. Further, in the embodiment, at the time of reproduction, all the directories on the optical card are once read into the buffer memory and then the directories are read one by one from the buffer memory for processing, but the same directory is read twice during processing. This is because it is necessary to read, and the processing speed is faster when reading from the buffer memory than when reading from the optical card, but if the processing speed does not matter or you want to save the buffer memory,
It may be read from the optical card every time.

Further, in the embodiment, for the sake of simplicity of explanation, it is assumed that there is no directory whose file size is 0 bytes. However, when the information recording / reproducing apparatus is controlled by an operating system such as MS-DOS, there is a possibility that a directory whose managed file size is 0 byte is recorded. In this case, since there is no entity of the file managed by the directory, whether the file capacity managed by the directory read in steps 102 and 108 is 0 bytes before steps 103 and 109 in FIG. A step for checking whether or not each is provided, and if it is not 0 bytes, proceed to the next step (step 103 and step 109). If it is 0 byte, no FAT creation processing is performed and the processing proceeds directly to step 113. Should be added.

[0038]

As described above, according to the present invention, when a file to which data has been added is reproduced for each recording unit, the information added continuously is reproduced only by sequentially reproducing from the first recording unit according to FAT. Reproduction is possible, and the data of each recording unit to be reproduced is only valid data except for the final recording unit of the last partial file. Therefore, without performing any complicated processing, simply follow the information indicated by the FAT. You can easily play it just by playing it. Even if the file size of the partial file is an integral multiple of the capacity of the recording unit as in the conventional case, the valid data recorded in the final recording unit is managed as invalid data and the data is lost. There is no problem.

Furthermore, even if the medium cannot be erased and rewritten,
If the last recording unit of the file has an invalid data section,
There is also an advantage that the information of the final recording unit of the file can be logically updated. Especially, if the size of the file is (capacity of recording unit-1 byte) or less, all data can be logically updated. . In addition, when the capacity of the added file and the data to be added is a small fraction of the data capacity of the recording unit, the number of reproduction recording units for reproducing the entire added file is small, There are many advantages such as the advantage that the time required can be shortened.

[Brief description of drawings]

FIG. 1 is a flowchart showing a process of creating a FAT from directory information in the file management method of the present invention.

FIG. 2 is a flowchart showing a process at the time of additional recording of data to a file according to the file management method of the present invention.

FIG. 3 is a diagram showing a file of a data section of an optical card.

FIG. 4 is a diagram showing a directory in a directory portion of an optical card.

FIG. 5 is a diagram showing data on a buffer memory of a host computer.

6 is an FA created according to the flowchart of FIG.
It is the figure which showed T.

FIG. 7 is a schematic plan view showing an example of an optical card.

FIG. 8 is a diagram for explaining the concept of FAT.

FIG. 9 is a diagram for explaining addition of data to a file using a conventional append flag.

[Explanation of symbols]

 10 data part 20 directory part 30 FAT 201, 202, 308, 309 file 204, 205, 311 invalid data part 306, 310 valid data part 400 buffer memory 301, 302, 303, 304 directory

Claims (1)

[Claims] 1. A data section for recording file data,
When additionally recording data in an existing file using a recording medium having a directory section for recording a directory for managing the file data, the data to be added is stored in the data section as a file different from the existing file. By recording a directory for recording and managing the additional file data in the directory portion by incrementing a flag indicating addition of file data included in the directory, files having the same file name but different flags are recorded. In the file management method of managing as one file dividedly recorded in the order of the flag numbers, when the final recording unit of the file to which data is added has invalid data, the valid data of the final recording unit is read into the storage means, In addition, the data to be added is stored in the effective data of the storage means. When the data is reproduced, the file name is the same and the flag is other than the maximum value, and the file size is not an integral multiple of the predetermined recording unit. A file management method characterized in that the final recording unit of the file is managed as an invalid recording unit.