How SQL Server reads and writes operating system files

DECLARE @object int
DECLARE @hr int
DECLARE @src varchar (255), @desc varchar (255)
Declare @tmp int
DECLARE @msg varchar (3000)

-------------------------1. Write the file--------------------------------------

--write this string of characters into the Nipsan.Txt file in the installation directory of SQL Server

SET @msg = ' Hello '.   MS SQL Server 2000. I Love you!!! '

--Get the installation path for SQL Server
DECLARE @strPath nvarchar (512)
Exec sp_msget_setup_paths @strPath OUTPUT

--Output path, file name
Set @[email protected]+ '/nipsan.txt '


--Create scripting Component Instances
EXEC @hr = sp_OACreate ' Scripting.FileSystemObject ', @object out
IF @hr <> 0
BEGIN
EXEC sp_OAGetErrorInfo @object, @src out, @desc out
SELECT Hr=convert (varbinary (4), @hr), [email protected], [email protected]
RETURN
END

--Create a file
EXEC @hr = sp_OAMethod @object, ' CreateTextFile ', @tmp OUTPUT, @strPath
IF @hr <> 0
BEGIN
EXEC sp_OAGetErrorInfo @object
RETURN
END
--Write the @msg to the file.
EXEC @hr = sp_OAMethod @tmp, ' Write ', NULL, @msg
IF @hr <> 0
BEGIN
EXEC sp_OAGetErrorInfo @object
RETURN
END

  --close the file stream   
  exec   @hr    =   sp_oamethod   @tmp,   ' Close ', null   
  IF    @hr    <>   0   
  begin   
         exec   sp_oageterrorinfo   @object    
          return   
  end   

   ------------------------------2. Open file-------------------------------------------------  
    
  EXEC   @hr    =   sp_oamethod   @object,   ' OpenTextFile ',   @tmp    output  , @strPath    
  if    @hr    <>   0   
  begin   
         exec   sp_oageterrorinfo   @object    
           return   
  end   
   

------------------------------3. Read the file-------------------------------------------------
SET @msg = ' '
EXEC @hr = sp_OAMethod @tmp, ' Read ', @msg out,3000
IF @hr <> 0
BEGIN
EXEC sp_OAGetErrorInfo @object
RETURN
END

SELECT @msg as RESULT

How SQL Server reads and writes operating system files