05-18-2024, 09:42 AM
@RhoSigma That "File Not Found" *is* an internal existence check. It tells you if the file isn't found, and then exits the process for you. Let me see if I can illustrate a little better what I'm trying to highlight here:
The old method would automatically CREATE a file when you OPEN FOR BINARY, if none existed before. That file would be size 0 in length; you'd read a 0-byte string, and then once you close the file, you're left with a size-0 file on your drive which you'd probably need to clean up.
With _ReadFile$, it checks to see if the file exists, and if it doesn't find it where you specified, it tosses the "File Not Found" error and then exits, returning you a 0-byte string if you click "Continue". What it doesn't do is create that file on your drive anywhere, so you never have to worry about cleaning up any junk files from your drive.
That "File Not Found" *is* a form of an existence check... at least, that's what I'd consider it to be. I suppose someone else might consider it to be an ERROR. I guess it's all just a matter of perspective on how you consider things.
What our new little command does, is actually something very similar to all the below here:
That's a pretty good reduction for a good bit of typing/coding, for one quick shortcut of a command.
Code: (Select All)
Open "temp.txt" For Output As #1: Close 'create a file
Kill "temp.txt" ' so we can kill that file to make certain it doesn't exist, without errors
If _FileExists("temp.txt") Then Print "Somethings wrong! We kilt it and it didn't die!"
Open "temp.txt" For Binary As #1
temp$ = Space$(LOF(1))
Get #1, 1, temp$
Close
If _FileExists("temp.txt") Then
Print "Even though there was no temp.txt, there is now! OPEN FOR BINARY made one!"
Else
Print "File still missing. Open For Binary didn't make one."
End If
Kill "temp.txt" ' kill that file
If _FileExists("temp.txt") Then Print "Somethings wrong! We kilt it and it didn't die!"
temp$ = _ReadFile$("temp.txt") ' and now readfile$ will toss an error for "File Not Found"
If _FileExists("temp.txt") Then
Print "Even though there was no temp.txt, there is now! ReadFile$ made one!"
Else
Print "File still missing, as ReadFile didn't make one."
End If
The old method would automatically CREATE a file when you OPEN FOR BINARY, if none existed before. That file would be size 0 in length; you'd read a 0-byte string, and then once you close the file, you're left with a size-0 file on your drive which you'd probably need to clean up.
With _ReadFile$, it checks to see if the file exists, and if it doesn't find it where you specified, it tosses the "File Not Found" error and then exits, returning you a 0-byte string if you click "Continue". What it doesn't do is create that file on your drive anywhere, so you never have to worry about cleaning up any junk files from your drive.
That "File Not Found" *is* a form of an existence check... at least, that's what I'd consider it to be. I suppose someone else might consider it to be an ERROR. I guess it's all just a matter of perspective on how you consider things.
What our new little command does, is actually something very similar to all the below here:
Code: (Select All)
Dim f As Long
Dim temp$
If _FileExists("temp.txt") = 0 Then
_MessageBox "ERROR -- File Not Found", "Error! File Not Found", "error"
Else
f = FreeFile
Open "temp.txt" For Binary As #f
temp$ = Space$(LOF(f))
Get #f, 1, temp$
Close #f
End If
That's a pretty good reduction for a good bit of typing/coding, for one quick shortcut of a command.