Looping through an open file

[Hap]

I have opened a text file and am attempting to loop through the lines of data. However, using the EOF function I can't seem to reset this setting without closing and reopening the file. So what's happening is when I try to start a new loop it recognizes that it's already at the end of the file and skips over the next loop. I'm assuming I'm missing something obvious. Any help would be greatly appreciated.

 

[shg]

A text file is not usually opened for random access -- you can't back it up.

Why not read the data into memory and loop there?

 

[Hap]

Would I effectively be reading to an array and then looping through the array? Mostly I have been trying to be conscious of execution speed.

 

[shg]

It will be much faster to loop through an array, if the whole file fits in memory.

 

[Hap]

I haven't worked with arrays much. Are vb arrays dynamic? if so whats the best way to determine the extents of the loops?

Thank you

 

[shg]

VBA arrays can be dynamic. Depending on the size of the file, you could read the file into a string variable and then use the Split function to separate it into lines.

 

[Rick Rothstein]

VBA arrays can be dynamic. Depending on the size of the file, you could read the file into a string variable and then use the Split function to separate it into lines.

To follow up on shg's message, here is some code to get you started...

Dim FileNum As Long, TotalFile As String, Lines() As String
FileNum = FreeFile
Open PathAndFileName For Binary As #FileNum
  TotalFile = Space(LOF(FileNum))
  Get #FileNum, , TotalFile
Close #FileNum
Lines = Split(TotalFile, vbNewLine)

After the above code runs, the Lines array contains each Windows newline character sequence (Carriage Return followed by a Line Feed) delimited line within the file in a separate array element.

 

[Hap]

This is what I have so far although it is in a infinite loop so I'm missing something. I was going to determine the number of columns in my aArray and redim similar to what I was doing for each line. Whaddya think?

Do Until EOF(1)
Line Input #1, aLine
If InStr(1, aLine, "Type", 1) Then

For i = 1 To 256
If GetElement(aLine, ",", i) = "" Then
j = j + 1
End If
Next i
Exit Do
End If
Loop

ReDim aArray(1, j)
k = 1
Do Until EOF(1)
Line Input #1, aLine
For i = 1 To j
Do Until i = j
aArray(k, i) = GetElement(aLine, ",", i)
Loop
ReDim Preserve aArray(UBound(aArray) + 1, j)
k = k + 1
Next i
Loop

 

[Hap]

The GetElement function I believe is something from CPearson's site. It returns the value at the i location in the aline.

 

[shg]

Could you explain what you're trying to do, without reference to your code?