Wrap I/O for Text Files

Wrap I/O for Text Files

In a production application, every time you want to access a file for reading or writing, you must retrieve a free handle using the FreeFile() function to ensure you don’t overwrite an existing handle. You also must remember to close the file after you finish with it. In some cases, you can avoid the trouble by encasing this functionality inside utility functions. For example, I wrote these two functions to go between strings and text files in my apps:

 Public Function ReadFile(FileName As String) As String	Dim hFile As Integer	hFile = FreeFile	On Error GoTo ErrorTrap		Open FileName For Input As #hFile		ReadFile = Input(LOF(hFile), hFile)		Close # hFile	Exit FunctionErrorTrap:	ReadFile = ""End FunctionPublic Sub WriteFile(FileName As String, Contents As 	_	String)	Dim hFile As Integer	hFile = FreeFile	On Error Resume Next	Open FileName For Output As #hFile	Print #hFile, Contents;	Close #hFileEnd Sub

Once you put these functions in your project, you can read and write text files quickly. For example, here’s a way you might use these functions to copy text files:

 Call WriteFile("c:.txt", ReadFile("c:a.txt"))


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