Search engine in vb.net - vb.net

I am building a search engine in vb.net which would have to search for a word entered by the user in 40 text files within the project directory.
It should return the results as the total number of matches (text files) and the number of times this word is in each file. Any suggestions for a start would be grateful.
Regards.

get a list of the files in the directory with something like: Directory.GetFiles(ProjectDir, "*.*"), then read each file in the list like this:
Dim sr As StreamReader = New StreamReader(fileName)
Dim line As String
Do
line = sr.ReadLine()
scan the line and count
Loop Until line Is Nothing
sr.Close()

Try this code, in a console application, not only could find a word
even you can get the results using a RegEx Expression.
Class TextFileInfo
Public File As System.IO.FileInfo
public Count As Integer
public FileText As String
public ItMatch as Boolean = False
Sub New (FileFullName as String,WordPattern as String)
File = new System.IO.FileInfo(FileFullName)
Using Fs As System.IO.StreamReader(File.FullName)
FileText = Fs.ReadToEnd()'//===>Read Text
End Using
Count = _CountWords(WordPattern,FileText)
ItMatch = Count > 0
End Sub
Public Sub DisplayInfo()
System.Console.WriteLine("File Name:" + File.Name)
System.Console.WriteLine("Matched Times:" & Count)
End Sub
Private Function _CountWords(Word As String,Text As String) as Integer
Dim RegEx as System.Text.RegularExpressions.Regex(Word)
return RegEx.Matches(Text).Count'//===>Returns how many times this word match in the Text
End Fuction
End Class
Public Function SearchEngine(PatternWord As String,RootDirectory As String) List(Of TextFileInfo)
Dim MatchedFiles As New List(Of TextFileInfo)
Dim RootDir As New System.IO.DirectoryInfo(RootDirectory)
For Each iTextFile as System.IO.FileInfo In RootDir.GetFiles("*.txt")
'//===>Create a object of TextFileInfo and check if the file contains the word
Dim iMatchFile as New TextFileInfo(iTextFiles.FullName,PatternWord)
If iMatchFile.ItMatch Then
'//===>Add the object to the list if it has been matches
MatchedFiles.Add(iMatchFile)
End If
Loop
retur MatchedFiles '//===>Return the results of the files that has the matched word
End Function
Sub Main()
Dim SearchResults as List(Of TextFileInfo) = SearchEngine("JajajaWord","C:\TextFiles\")
For Each iSearch As TextFileInfo In SearchResults
iSearch.DisplayInfo()
Loop
End Sub

Related

Index of line textfile using StreamReader vb.net

How can I use this code?
TextBox1.Text = Array.FindIndex(linestring, Function(s) s.Contains(something))
but to use the code, without a word, and to display my array index following the code below:
Dim lines As New List(Of String)
Using reader As New StreamReader(My.Application.Info.DirectoryPath + ("\Data.txt"))
Dim line As String
Do Until line.StartsWith(endPrefix)
lines.Add(line)
line = reader.ReadLine()
'maybe here index of array
Loop
so how do I use this to get the line index from my text files?
Here is an example which uses the File.ReadLines method (which enumerates the lines of a file) where you can pass the predicate for the comparison to get the line number (starting at 1) of the first match:
Imports System.IO
Module Module1
Function FindLineNumber(sourceFile As String, textToFind As String, predicate As Func(Of String, String, Boolean)) As Integer
Dim lineNo = 1
For Each l In File.ReadLines(sourceFile)
If predicate(l, textToFind) Then
Return lineNo
End If
lineNo += 1
Next
Return -1
End Function
Sub Main()
' File to look in:
Dim src = "C:\temp\population.csv"
' Text to find:
Dim find = "133"
Dim lineNum = FindLineNumber(src, find, Function(a, b) a.Contains(b))
If lineNum > 0 Then
Console.WriteLine($"""{find}"" found at line {lineNum}.")
Else
Console.WriteLine($"""{find}"" not found.")
End If
Console.ReadLine()
End Sub
End Module

Getfile with multiple extension filter and order by file name

i am working on vb.net desktop application.now i need that files coming from directory is in with extension .txt and .sql and also need that files coming in order by folder name. in need both together how to do it?
Try
Dim s As String = Txtfolder.Text
Dim files As List(Of String) = New List(Of String)()
Try
For Each f As String In Directory.GetFiles(s, "*.*").Where(Function(f1) f1.EndsWith(".sql") OrElse f1.EndsWith(".txt")).OrderBy(Function(f) f.LastWriteTime).First()
files.Add(f)
Next
For Each d As String In Directory.GetDirectories(s)
files.AddRange(DirSearch(d))
Next
Catch excpt As System.Exception
MessageBox.Show(excpt.Message)
End Try
Private Function DirSearch(ByVal sDir As String) As List(Of String)
Dim files As List(Of String) = New List(Of String)()
Try
For Each f As String In Directory.GetFiles(sDir, "*.*").Where(Function(f1) f1.EndsWith(".sql") OrElse f1.EndsWith(".txt"))
files.Add(f)
Next
For Each d As String In Directory.GetDirectories(sDir)
files.AddRange(DirSearch(d))
Next
Catch excpt As System.Exception
MessageBox.Show(excpt.Message)
End Try
Return files
End Function
Here is an example of option 1 from my comment, i.e. get all file paths and filter yourself:
Dim folderPath = "folder path here"
Dim filePaths = Directory.GetFiles(folderPath).
Where(Function(s) {".txt", ".sql"}.Contains(Path.GetExtension(s))).
OrderBy(Function(s) Path.GetFileName(s)).
ToArray()
Here's an example of option 2, i.e. get paths by extension and combine:
Dim folderPath = "folder path here"
Dim filePaths = Directory.GetFiles(folderPath, "*.txt").
Concat(Directory.GetFiles(folderPath, "*.sql")).
OrderBy(Function(s) Path.GetFileName(s)).
ToArray()
An alternative method, which allows searching for multiple directories and filtering the results using multiple search patterns.
It returns an ordered List(Of String):
Private Function DirSearch(ByVal sDirList As String(), SearchPatter As String()) As List(Of String)
Return sDirList.SelectMany(
Function(dir) SearchPatter.SelectMany(
Function(filter)
Return Directory.GetFiles(dir, filter, SearchOption.AllDirectories)
End Function).OrderBy(Function(xDir) xDir)).ToList()
End Function
You can pass the method a list of paths and a list of extensions:
Dim SearchPaths As String() = New String() {"[Directory1]", "[Directory2]"}
Dim ItemSearchPattern As String() = New String() {"*.txt", "*.sql", "*.jpg"}
Dim DirListing As List(Of String) = DirSearch(SearchPaths, ItemSearchPattern)
Extract the content of a sigle directory with:
Dim FilesInDir As List(Of String) = DirListing.
Where(Function(entry) entry.ToUpper().
Contains("[DirectoryName]".ToUpper())).ToList()
This is a case insensitive filter. Remove (ToUpper()) for a case sensitive one.

how to write to/read from a "settings" text file

I'm working on a Timer program, that allows the user to set up a timer for each individual user account on the computer. I'm having some trouble writing the settings to a text file and reading from it. I want to know if it's possible to write it in this fashion --> username; allowedTime; lastedLoggedIn; remainingTime; <-- in one line for each user, and how would I go about doing that? I also wanted to know if it's possible to alter the text file in this way, in the case that there's already an entry for a user, only change the allowedTime, or the remainingTime, kinda just updating the file?
Also I'm also having trouble being able to read from the text file. First of all I can't figure out how to determine if a selected user is in the file or not. Form there, if the user is listed in the file, how can access the rest of the line, like only get the allowedTime of that user, or the remaining time?
I tried a couple of ways, but i just can't get it to do how I'm imaging it, if that makes sense.
here's the code so far:
Public Sub saveUserSetting(ByVal time As Integer)
Dim hash As HashSet(Of String) = New HashSet(Of String)(File.ReadAllLines("Settings.txt"))
Using w As StreamWriter = File.AppendText("Settings.txt")
If Not hash.Contains(selectedUserName.ToString()) Then
w.Write(selectedUserName + "; ")
w.Write(CStr(time) + "; ")
w.WriteLine(DateTime.Now.ToLongDateString() + "; ")
Else
w.Write(CStr(time) + "; ")
w.WriteLine(DateTime.Now.ToLongDateString() + "; ")
End If
End Using
End Sub
Public Sub readUserSettings()
Dim currentUser As String = GetUserName()
Dim r As List(Of String) = New List(Of String)(System.IO.File.ReadLines("Settings.txt"))
'For Each i = 0 to r.lenght - 1
'Next
'check to see if the current user is in the file
MessageBox.Show(r(0).ToString())
If r.Contains(selectedUserName) Then
MessageBox.Show(selectedUserName + " is in the file.")
'Dim allowedTime As Integer
Else
MessageBox.Show("the user is not in the file.")
End If
'if the name is in the file then
'get the allowed time and the date
'if the date is older than the current date return the allowed time
'if the date = the current date then check thhe remaning time and return that
'if the date is ahead of the current date return the reamining and display a messgae that the current date needs to be updated.
End Sub
edit: I just wanted to make sure if I'm doing the serialization right and the same for the deserialization.
this is what i got so far:
Friend userList As New List(Of Users)
Public Sub saveUserSetting()
Using fs As New System.IO.FileStream("Settings.xml", IO.FileMode.OpenOrCreate)
Dim bf As New BinaryFormatter
bf.Serialize(fs, userList)
End Using
End Sub
Public Sub readUserSettings()
Dim currentUser As String = GetUserName()
Dim useList As New List(Of Users)
Using fs As New System.IO.FileStream("Settings.xml", IO.FileMode.OpenOrCreate)
Dim bf As New BinaryFormatter
useList = bf.Deserialize(fs)
End Using
MessageBox.Show(useList(0).ToString)
End Sub
<Serializable>
Class Users
Public userName As String
Public Property allowedTime As Integer
Public Property lastLoggedInDate As String
Public Property remainingTime As Integer
Public Overrides Function ToString() As String
Return String.Format("{0} ({1}, {2}, {3})", userName, allowedTime, lastLoggedInDate, remainingTime)
End Function
End Class
edit 2:
I'm not too familiar with try/catch but would this work instead?
Public Sub readUserSettings()
If System.IO.File.Exists("Settings") Then
Using fs As New System.IO.FileStream("Settings", FileMode.Open, FileAccess.Read)
Dim bf As New BinaryFormatter
userList = bf.Deserialize(fs)
End Using
Else
MessageBox.Show("The setting file doesn't exists.")
End If
End Sub
You have a few typos and such in your code, but it is pretty close for your first try:
Friend userList As New List(Of Users)
Public Sub saveUserSetting()
' NOTE: Using the BINARY formatter will write a binary file, not XML
Using fs As New System.IO.FileStream("Settings.bin", IO.FileMode.OpenOrCreate)
Dim bf As New BinaryFormatter
bf.Serialize(fs, userList)
End Using
End Sub
Public Sub readUserSettings()
' this doesnt seem needed:
Dim currentUser As String = GetUserName()
' do not want the following line - it will create a NEW
' useRlist which exists only in this procedure
' you probably want to deserialize to the useRlist
' declared at the module/class level
' Dim useList As New List(Of Users)
' a) Check if the filename exists and just exit with an empty
' useRlist if not (like for the first time run).
' b) filemode wass wrong - never create here, just read
Using fs As New System.IO.FileStream("Settings.bin",
FileMode.Open, FileAccess.Read)
Dim bf As New BinaryFormatter
' user list is declared above as useRList, no useList
useList = bf.Deserialize(fs)
End Using
' Console.WriteLine is much better for this
MessageBox.Show(useList(0).ToString)
End Sub
<Serializable>
Class Users
' I would make this a property also
Public userName As String
Public Property allowedTime As Integer
Public Property lastLoggedInDate As String
Public Property remainingTime As Integer
Public Overrides Function ToString() As String
Return String.Format("{0} ({1}, {2}, {3})", userName, allowedTime, lastLoggedInDate, remainingTime)
End Function
End Class
ToDo:
a) decide whether you want XML or binary saves. With XML, users can read/edit the file.
b) Use a file path created from Environment.GetFolder(); with a string literal it may end up in 'Program Files' when deployed, and you cannot write there.
c) when reading/loading the useRlist, use something like
FileStream(myUserFile, FileMode.Open, FileAccess.Read)
It wont exist the first time run, so check if it does and just leave the list empty. After that, you just need to open it for reading. For saving use something like:
FileStream(myUserFile, FileMode.OpenOrCreate, FileAccess.Write)
You want to create it and write to it. You might put the Load/Save code inside a Try/Catch so if there are file access issues you can trap and report them, and so you know the list did not get saved or read.
Using a serializer, the entire contents of the list - no matter how long - will get saved with those 3-4 lines of code, and the entire list read back in the 2-3 lines to load/read the file.
I don't have the answer to all your questions however I've been also working on a timer application and just recently started using text file to read and write information. The method I'm using has proven itself fairly easy to use and not very confusing. Here is an extract of my code:
Dim startup As String = "C:\Users\DigiParent\Desktop\Project data\Digitimeinfo.txt"
Dim reader As New System.IO.StreamReader(startup, Encoding.Default)
Dim data As String = reader.ReadToEnd
Dim aryTextFile(6) As String
aryTextFile = data.Split(",")
This will read everything in the text file and in sort separate everything in between the , and store them individual in the array. To put the code back in one line use
Dim LineOfText As String
LineOfText = String.Join(",", aryTextFile)
so you could write someting like this to write your info to a text file:
Dim startup As String = "C:\Users\DigiParent\Desktop\Project data\Digitimeinfo.txt"
Dim objWriter As New System.IO.StreamWriter(startup, False)
Dim aryTextFile(2) As String
aryTextFile(0) = pasword
aryTextFile(1) = user
aryTextFile(2) = remainingtime
LineOfText = String.Join(",", aryTextFile)
objWriter.WriteLine(LineOfText)
objWriter.Close()
and to read it you could use steam reader.

Searching By File Extensions VB.NET [duplicate]

This question already has answers here:
What is a NullReferenceException, and how do I fix it?
(27 answers)
Closed 5 years ago.
Hi all i have been trying to search a specified directory and all sub directories for all files that have the specified file extension. However the inbuilt command is useless as it errors up and dies if you dont have access to a directory. So here's what i have at the moment:
Private Function dirSearch(ByVal path As String, Optional ByVal searchpattern As String = ".exe") As String()
Dim di As New DirectoryInfo(path)
Dim fi As FileInfo
Dim filelist() As String
Dim i As Integer = 0
For Each fi In di.GetFiles
If System.IO.Path.GetExtension(fi.FullName).ToLower = searchpattern Then
filelist(i) = fi.FullName
i += 1
End If
Next
Return filelist
End Function
However i get an "System.NullReferenceException: Object reference not set to an instance of an object." when i try to access the data stored inside the filelist string array.
Any idea's on what im doing wrong?
You didn't instantiate the Dim filelist() As String array. Try di.GetFiles(searchPattern)
Dim files() as FileInfo = di.GetFiles(searchPattern)
Use static method Directory.GetFiles that returns an array string
Dim files = Directory.GetFiles(Path,searchPattern,searchOption)
Demo:
Dim files() As String
files = Directory.GetFiles(path, "*.exe", SearchOption.TopDirectoryOnly)
For Each FileName As String In files
Console.WriteLine(FileName)
Next
Recursive directory traversal:
Sub Main()
Dim path = "c:\jam"
Dim fileList As New List(Of String)
GetAllAccessibleFiles(path, fileList)
'Convert List<T> to string array if you want
Dim files As String() = fileList.ToArray
For Each s As String In fileList
Console.WriteLine(s)
Next
End Sub
Sub GetAllAccessibleFiles(path As String, filelist As List(Of String))
For Each file As String In Directory.GetFiles(path, "*.*")
filelist.Add(file)
Next
For Each dir As String In Directory.GetDirectories(path)
Try
GetAllAccessibleFiles(dir, filelist)
Catch ex As Exception
End Try
Next
End Sub
Use System.IO.Directory.EnumerateFiles method and pass SearchOption.AllDirectories in to traverse the tree using a specific search pattern. Here is an example:
foreach (var e in Directory.EnumerateFiles("C:\\windows", "*.dll", SearchOption.AllDirectories))
{
Console.WriteLine(e);
}

compare and merge multiple files the text file using VB.NET

I have a multiple text files that I need to merge. but I need to compare the reference number before merge it.
below is the text file
Text 1
001Email
002Video
003SocialNetwork
Text 2
001Gmail
001Yahoo
002Youtube
002Metacafe
003Facebook
003Myspace
Text 3
www.gmail.com001
www.yahoo.com001
www.youtube.com002
www.myspace.com002
www.facebook.com003
www.myspace.com003
Output
001Email
001Gmail
www.gmail.com001
001Yahoo
wwww.yahoo.com001
002Video
002Youtube
www.youtube.com002
002Metacafe
www.metacafe.com002
003SocialNetwork
003Facebook
www.facebook.com003
003Myspace
www.myspace.com003
What will be the fastest way to deal it read line by line to compare. the text file consist of thousand of line
Here's what might possibly be an overly complex solution. The comments in the code should explain everything hopefully. The output doesn't match exactly what you have because I don't know how much order is important for everything. It sorts everything first by the reference number and then by the text portion of the string (excluding www.). The results you posted were in reference number order and then file parsing order and then alphabetical (002Metacafe came after 002Video). Let me know if that's important.
Option Explicit On
Option Strict On
Imports System.IO
Imports System.Text.RegularExpressions
Public Class Form1
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
''//List of files to process
Dim Files As New List(Of String)
Files.Add(Path.Combine(My.Computer.FileSystem.SpecialDirectories.Desktop, "Text1.txt"))
Files.Add(Path.Combine(My.Computer.FileSystem.SpecialDirectories.Desktop, "Text2.txt"))
Files.Add(Path.Combine(My.Computer.FileSystem.SpecialDirectories.Desktop, "Text3.txt"))
''//Will hold the current line being read
Dim Line As String
''//Holds our main collection of data
Dim MyData As New List(Of Data)
''//Loop through each file
For Each F In Files
''//Open the file for reading
Using FS As New FileStream(F, FileMode.Open, FileAccess.Read, FileShare.Read)
Using SR As New StreamReader(FS)
''//Read each line
Line = SR.ReadLine()
Do While Line IsNot Nothing
''//The data constructor handles parsing of the line
MyData.Add(New Data(Line))
''//Read next line
Line = SR.ReadLine()
Loop
End Using
End Using
Next
''//Our data implements IComparable(Of Data) so we can just sort the list
MyData.Sort()
''//Output our data
For Each D In MyData
Trace.WriteLine(D)
Next
Me.Close()
End Sub
End Class
Public Class Data
Implements IComparable(Of Data)
''//Our RegEx pattern for looking for a string that either starts or ends with numbers
Private Shared ReadOnly Pattern As String = "^(?<RefStart>\d+)?(?<Text>.*?)(?<RefEnd>\d+)?$"
Public Text As String ''//The _text_ portion of the data
Public Reference As String ''//The reference number stored as text
Public ReferenceAtStart As Boolean ''//Whether the reference number was found at the start or end of the line
Public ReadOnly Property ReferenceAsNum() As Integer ''//Numeric version of the reference number for sorting
Get
Return Integer.Parse(Me.Reference)
End Get
End Property
Public ReadOnly Property TextComparable() As String ''//Remove the www for sorting
Get
Return Me.Text.Replace("www.", "")
End Get
End Property
Public Sub New(ByVal line As String)
''//Sanity check
If String.IsNullOrEmpty(line) Then Throw New ArgumentNullException("line")
''//Parse the line
Dim M = Regex.Match(line, Pattern)
If M Is Nothing Then Throw New ArgumentException("Line does not conform to expected pattern")
''//If the RefStart has a value then the number is at the beginning of the string
If M.Groups("RefStart").Success Then
Me.ReferenceAtStart = True
Me.Reference = M.Groups("RefStart").Value
Else ''//Otherwise its at the end
Me.ReferenceAtStart = False
Me.Reference = M.Groups("RefEnd").Value
End If
Me.Text = M.Groups("Text").Value
End Sub
Public Function CompareTo(ByVal other As Data) As Integer Implements System.IComparable(Of Data).CompareTo
''//Compare the reference numbers first
Dim Ret = Me.ReferenceAsNum.CompareTo(other.ReferenceAsNum)
''//If they are the same then compare the strings
If Ret = 0 Then Ret = String.Compare(Me.TextComparable, other.TextComparable, StringComparison.InvariantCultureIgnoreCase)
Return Ret
End Function
Public Overrides Function ToString() As String
''//Reproduce the original string
If Me.ReferenceAtStart Then
Return String.Format("{0}{1}", Me.Reference, Me.Text)
Else
Return String.Format("{1}{0}", Me.Reference, Me.Text)
End If
End Function
End Class