Replace all text in text file using regular expression - vba

Question

I have a text file with following text
161624.406 : Send:[sometext1]
161624.437 : Send:[sometext2]
161624.468 : Send:[sometext3]
161624.499 : Send:[sometext4]
161624.531 : Send:[sometext5]
I want to keep only the sometext part in that file. Desired output is
sometext1
sometext2
sometext3
sometext4
sometext5
I am using the following code in Excel-VBA
Public Sub testa()
a = "C:\Users\pankaj.jaju\Desktop\test.log"
Set objFSO = CreateObject("Scripting.FileSystemObject")
Set objTxtFile = objFSO.OpenTextFile(a, 1)
strText = objTxtFile.ReadAll
objTxtFile.Close
Set objTxtFile = Nothing
Set objRegEx = CreateObject("VBScript.RegExp")
With objRegEx
.Global = True
.MultiLine = True
.Pattern = "\[([^]]+)\]"
Set objRegMC = .Execute(strText)
b = objRegMC(0).SubMatches(0)
End With
Set objRegEx = Nothing
Debug.Print b
End Sub
The problem is the output is displayed as sometext1 only. How do I ReplaceAll in the text file and save the file with the desired text only.

Answer 1

The regex.Replace method should do the trick.
Separate your pattern into groups like this: "(.*?)(\[)([^]]+)(\])(.*?)"
And now you can replace your input string with the matching group which is group three in this case: objRegEx.Replace(strText, "$3")
Here is a helpful link to different examples of Regex within Excel.

Answer 2

I know you've already got your answer. But for a simple program like this, why even utilize regular expressions? Here's a 4 line script that can do the same thing - yes it has been tested.
Dim a, text: a = "C:\testenv\test.log"
text = split(CreateObject("Scripting.FileSystemObject").OpenTextFile(a, 1).ReadAll, vbcrlf)
for i=0 to ubound(text) : text(i) = replace(split(text(i), "[")(1), "]", "") : next
CreateObject("Scripting.FileSystemObject").OpenTextFile(a, 2).Write(Join(text, vbcrlf))

Answer 3

The regex obviously only grabbing the first match of the string. I'm not proficient enough with regex to come up with a regex only solution that takes into account \n
A simple workaround would be to use objTxtFile.ReadLine instead of ReadAll
Read each string in one by one, apply regex and get output.
Public Sub testa()
a = "C:\Users\pankaj.jaju\Desktop\test.log"
Set objFSO = CreateObject("Scripting.FileSystemObject")
Set objTxtFile = objFSO.OpenTextFile(a, 1)
Do Until (objTxtFile.AtEndOfStream) 'Loop till EOF
strText = objTxtFile.ReadLine 'Single line read instead of ReadAll
Set objRegex = CreateObject("VBScript.RegExp")
With objRegex
.Global = True
.MultiLine = True
.Pattern = "\[([^]]+)\]"
Set objRegMC = .Execute(strText)
b = objRegMC(0).SubMatches(0)
End With
Set objRegex = Nothing
Debug.Print b 'replace this with the code to output the string where you want etc
Loop
objTxtFile.Close
End Sub

Answer 4

OK ... found a way to do it (Thanks MSDN ... sometimes the docs are useful :-)). Sharing the answer
Public Sub testa()
a = "C:\Users\pankaj.jaju\Desktop\test.log"
Set objFSO = CreateObject("Scripting.FileSystemObject")
Set objTxtFile = objFSO.OpenTextFile(a, 1)
strText = objTxtFile.ReadAll
objTxtFile.Close
Set objTxtFile = Nothing
b = ""
Set objRegEx = CreateObject("VBScript.RegExp")
With objRegEx
.Global = True
.MultiLine = True
.Pattern = "\[([^]]+)\]"
Set objMatches = .Execute(strText)
For Each Match In objMatches
For Each SubMatch In Match.SubMatches
b = b & SubMatch & vbCrLf
Next SubMatch
Next Match
End With
Set objRegEx = Nothing
Set objTxtFile = objFSO.OpenTextFile(a, 2)
objTxtFile.Write b
objTxtFile.Close
Set objTxtFile = Nothing
End Sub
EDIT - Based on #PortlandRunner's suggestion
Public Sub testa()
a = "C:\Users\pankaj.jaju\Desktop\test.log"
Set objFSO = CreateObject("Scripting.FileSystemObject")
Set objTxtFile = objFSO.OpenTextFile(a, 1)
strText = objTxtFile.ReadAll
objTxtFile.Close
Set objTxtFile = Nothing
b = ""
Set objRegEx = CreateObject("VBScript.RegExp")
With objRegEx
.Global = True
.MultiLine = True
.Pattern = "(.*?)(\[)([^]]+)(\])(.*?)"
b = objRegEx.Replace(strText, "$3")
End With
Set objRegEx = Nothing
Set objTxtFile = objFSO.OpenTextFile(a, 2)
objTxtFile.Write b
objTxtFile.Close
Set objTxtFile = Nothing
End Sub