9.1 The syntax of the FILE statements:

1. Backup all subdirectories and files in the system data directory to the specifical directory.
Syntax: FILE BACKUP PathName
Return: Integer
Explain: Return Integer(0) if executed successfully; throw a error message if failed.

2. Restore all subdirectories and files in the specifical directory to the system data directory.
Syntax: FILE RESTORE PathName
Return: Integer
Explain: Return Integer(0) if executed successfully;throw a error message if failed.

3. Get all subdirectories in a directory.
Syntax: FILE GETCATALOGS
Return: String
Explain: Use the delimiter '\n' between one catalogname and another catalogname;  throw a error message if failed.

4. Get all files in a directory.
Syntax: FILE GETFILES
Return: String
Explain: Use the delimiter '\n' between one filename and another filename; throw a error message if failed.

5. Read the binary file.
Syntax: FILE READBINARY FileName
Return: java.io.InputStream
Explain: Return java.io.InputStream if executed successfully; throw a error message if failed.

6. Create and write the binary file.
Syntax: FILE WRITEBINARY FileName
Return: java.io.OutputStream
Explain: Return java.io.OutputStream if executed successfully; throw a error message if failed.

7. Check whether a file exists.
Syntax: FILE EXIST FileName
Return: Boolean
Explain: Return Boolean(true) if executed successfully; else return Boolean(false).

8. Rename a file.
Syntax: FILE RENAME SourceFileName,DestFileName
Return: Boolean
Explain: Return Boolean(true) if executed successfully; else return Boolean(false).

9. Check whether the time when the source file is updated is later than the time when the destination file is updated.
Syntax: FILE ISUPDATE SourceFileName,DestFileName  
Return: Boolean
Explain: Return Boolean(true) if the time updating the  source file is later than the destination file;else return Boolean(false).
.

10. Delete a directory or a file.
Syntax: FILE DELETE FileName
Return: Boolean
Explain: Return Boolean(true) if executed successfully; else return Boolean(false).

9.2 The execution of the FILE statements
The interface method of the FILE statements: execute(String cmd).
The method returns Object object;you can convert the object into a corresponding object as follows: Integer,String,InputStream,OutputStream,Boolean,then continue other manipulations. 

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