Geek Speak.

This is a pretty handy set of functions. In lots of the other scripts I have published, I have hard coded in a temporary working file name to copy our data into while we are trying to process data. While this works fine and dandy when there is just one copy of the script running, if you are calling a function recursively or running more than one copy of the script at a time, you will run into errors because the scripts will step on top of each other trying to copy data into, and out of the same working file.

This is kind of a bummer that wasn't immediately foreseen. Well, that's an easy fix too. All we have to do to resolve that is write yet another function to generate a random file name, and one more to make sure that the file name we create doesn't already exist in our temporary working directory.

We can do this a variety of ways but for the sake of compactness and neatness we can loop through the ASCII character numbers so we don't have to list every single character out and associate them with the random number that is created. The first function, "RndFileName" will generate the random 8.3 file name no questions asked. Quick and dirty.

The second function, "TempFile" calls the first function, generating the file name, but also checks our %TEMP% folder to ensure that this file doesn't already exist. If it does, it re-calls the "RndFileName" function in a do-loop until it finds a filename that isn't in use, then returns this file name as it's value.

Here is the code:

Function RndFileName()   'This function will generate an alpha-numeric random 8.3   'file name that ends in .tmp. This function does not accept   'any arguments.   'This script is provided under the Creative Commons license located   'at http://creativecommons.org/licenses/by-nc/2.5/ . It may not   'be used for commercial purposes with out the expressed written consent   'of NateRice.com     For x=1 To 8     Randomize     vChar = Int(36*Rnd)     If vChar < 10 Then 'append number       RndFileName = RndFileName & vChar     Else 'else append a letter       RndFileName = RndFileName & Chr(97+(vChar-10))     End If   Next   RndFileName = RndFileName & ".tmp" End Function Function TempFile()   'We'll use this function to generate a working temp file name   'that we can reliably copy data into and out of while   'we're generating data. We don't actually create the file   'here we just generate the name and verify that a file of   'this name doesn't already exist. We can use this function to   'generate an 8.3 temporary random file name so that we can   'call our other functions recursively or run 2 scripts at the   'same time without encountering weird errors. This function   'does not accept any arguemtents.   'This script is provided under the Creative Commons liscense located   'at http://creativecommons.org/licenses/by-nc/2.5/ . It may not   'be used for comercial purposes with out the expressed written consent   'of NateRice.com      Const OpenAsDefault = -2   Const FailIfNotExist = 0   Const ForReading = 1      Set oShell = CreateObject("WScript.Shell")   Set oFSO = CreateObject("Scripting.FileSystemObject")   sTemp = oShell.ExpandEnvironmentStrings("%TEMP%")      Do Until sGenerationIsSuccessful     sWorkingFileName = RndFileName     If oFSO.FileExists(sTemp & "\" & sWorkingFile) Then       'File exists loop again       sGenerationIsSuccessful = False     Else       'File Doesn't exist and is safe to use       sGenerationIsSuccessful = True     End If   Loop      TempFile = sWorkingFileName   Set oShell = Nothing   Set oFSO = Nothing End Function

That's all for now. Questions and comment's, as always, are welcome.