VB.NET Read Certain text in a text file - vb.net

Question

I want my program to read certain text in a text file. For example if I have a text file that contains the following info..
acc=blah
pass=hello
I want my vb.net application to get that the account variable is equal to blah, and the password variable is equal to hello.
Can anyone tell me how to do this?
Thanks

Answer 1

Here is a quick little bit of code that, after you click a button, will:
take an input file (in this case I created one called "test.ini")
read in the values as separate lines
do a search, using regular expressions, to see if it contains any "ACC=" or "PASS=" parameters
then write them to the console
here is the code:
Imports System.IO
Imports System.Text.RegularExpressions
Public Class Form1
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim strFile As String = "Test.INI"
Dim sr As New StreamReader(strFile)
Dim InputString As String
While sr.Peek <> -1
InputString = sr.ReadLine()
checkIfContains(InputString)
InputString = String.Empty
End While
sr.Close()
End Sub
Private Sub checkIfContains(ByVal inputString As String)
Dim outputFile As String = "testOutput.txt"
Dim m As Match
Dim m2 As Match
Dim itemPattern As String = "acc=(\S+)"
Dim itemPattern2 As String = "pass=(\S+)"
m = Regex.Match(inputString, itemPattern, _
RegexOptions.IgnoreCase Or RegexOptions.Compiled)
m2 = Regex.Match(inputString, itemPattern2, _
RegexOptions.IgnoreCase Or RegexOptions.Compiled)
Do While m.Success
Console.WriteLine("Found account {0}", _
m.Groups(1), m.Groups(1).Index)
m = m.NextMatch()
Loop
Do While m2.Success
Console.WriteLine("Found password {0}", _
m2.Groups(1), m2.Groups(1).Index)
m2 = m2.NextMatch()
Loop
End Sub
End Class

Answer 2

Have a look at this article
Reading and writing text files with VB.NET
Wile reading the file line by line, you can use String.Split Method with the splitter being "=", to split the string into param name, and param value.

Answer 3

Looks like you've got an INI file of some kind... The best way to read these is using the *PrivateProfile* functions of the windows API, which means you can actually have a proper full INI file quite easily for anything you need. There is a wrapper class here you may like to use.
Microsoft recommends that you use the registry to store this sort of information though, and discourages use of INI files.
If you wish to just use a file manually with the syntax you have, it is a simple case of splitting the string on '=' and put the results into a Dictionary. Remember to handle cases where the data was not found in the file and you need a default/error. In modern times though, XML is becoming a lot more popular for data text files, and there are lots of libraries to deal with loading from these.

Answer 4

My suggestion: you use XML. The .NET framework has a lot of good XML tools, if you're willing to make the transition to put all the text files into XML, it'll make life a lot easier.
Not what you're looking for, probably, but it's a cleaner solution than anything you could do with plain text (outside of developing your own parser or using a lower level API).

Answer 5

You can't really selectively read a certain bit of information in the file exclusively. You'll have to scan each line of the file and do a search for the string "pass=" at the beginning of the line. I don't know VB but look up these topics:
File readers (espically ones that can read one line at a time)
String tokenizers/splitting (as Astander mentioned)
File reading examples

Answer 6

Have you thought about getting the framework to handle it instead?
If you add an entry into the settings tab of the project properties with name acc, type string, scope user (or application, depending on requirements) and value pass, you can use the System.Configuration.ApplicationSettingsBase functionality to deal with it.
Private _settings As My.MySettings
Private _acc as String
Private _pass as String
Public ReadOnly Property Settings() As System.Configuration.ApplicationSettingsBase
Get
If _settings Is Nothing Then
_settings = New My.MySettings
End If
Return _settings
End Get
End Property
Private Sub SetSettings()
Settings.SettingsKey = Me.Name
Dim theSettings As My.MySettings
theSettings = DirectCast(Settings, My.MySettings)
theSettings.acc=_acc
theSettings.pass=_pass
Settings.Save()
End Sub
Private Sub GetSettings()
Settings.SettingsKey = Me.Name
Dim theSettings As My.MySettings
theSettings = DirectCast(Settings, My.MySettings)
_acc=theSettings.acc
_pass=theSettings.pass
End Sub
Call GetSettings in whatever load event you need, and SetSettings in closing events
This will create an entry in the application.exe.config file, either in your local settings \apps\2.0\etc etc directory, or your roaming one, or if it's a clickonce deployment, in the clickonce data directory. This will look like the following:-
<userSettings>
<MyTestApp.My.MySettings>
<setting name="acc" serializeAs="String">
<value>blah</value>
</setting>
<setting name="pass" serializeAs="String">
<value>hello</value>
</setting>
</MyTestApp.My.MySettings>
</userSettings>

Answer 7

Writing your own parser is not that hard. I managed to make one for a game (Using C#, but VB appears to have Regex class too. Using that, the acc variable in your file would be everything up to the = sign, and then blah would be everything past the = to the newline character (\n) Then go to the next line and repeat.

Answer 8

I have written this for you, check it and enjoy with the results, have a great day!
Public Class Form1
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Dim acc As New List(Of String)
Dim pass As New List(Of String)
Dim lines() As String = System.IO.File.ReadAllLines(".\credentials.txt")
For Each lineItem As String In lines
Dim vals() As String = lineItem.Split(Convert.ToChar("="))
If vals.Length > 0 Then
Dim lineId As String = vals(0)
If lineId = "acc" Then
acc.Add(vals(1))
ElseIf lineId = "pass" Then
pass.Add(vals(1))
End If
End If
Next
TextBox_acc.Text = String.Join(Environment.NewLine, acc)
TextBox_pass.Text = String.Join(Environment.NewLine, pass)
End Sub
End Class