I am trying to make a program that writes the binary code of a file in a separate text file.
When I use this program on a text file, it doesn't write anything in the new file. I then tested this for .jpg and .mp3 files and the program seems to write most of the binary code but leaves out the last couple of bytes. Here is my code:
Sub Main()
Console.Write("Filename: ")
Dim Filename As String = Console.ReadLine()
Console.Write("Extension: ")
Dim Extension As String = Console.ReadLine()
Console.WriteLine()
Dim Stream_1 As FileStream = New FileStream(Filename & "." & Extension, FileMode.Open)
Dim Stream_2 As FileStream = New FileStream(Filename & "_b.txt", FileMode.Create)
Dim Reader_1 As BinaryReader = New BinaryReader(Stream_1)
Dim Writer_2 As StreamWriter = New StreamWriter(Stream_2)
Dim File_Bytes() As Byte = Reader_1.ReadBytes(Convert.ToInt32(Stream_1.Length))
Dim Binary_String As String = ""
'These are used to a add line break after every 8 bytes
Dim Binary_String_Collection As String = ""
Dim Counter As Integer
For Each File_Byte In File_Bytes
Counter += 1
Binary_String = Convert.ToString(File_Byte, 2)
For I = 1 To 8 - Binary_String.Length
Binary_String = "0" & Binary_String
Next
Binary_String_Collection = Binary_String_Collection & Binary_String & " "
If Counter = 8 Then
Writer_2.WriteLine(Binary_String_Collection)
Counter = 0
Binary_String_Collection = ""
End If
Next
If Binary_String_Collection <> "" Then
Writer_2.WriteLine(Binary_String_Collection)
End If
Console.ReadLine()
End Sub
At first I thought that my program wasn't reading the binary code properly so I added console outputs at locations where it writes to the file. The program displayed correct output so I'm confused why it isn't writing properly.
Make sure you close the file and Dispose of the streams correctly.
Related
Newbie here. Code below removes ALL line feeds in my file but it also removes EOR line feeds. Can somebody please help me how to fix code below so it only removes extra line feeds within double quoted fields? Any help will be greatly appreciated. Thanks
Public Sub Main()
'
Dim objReader As IO.StreamReader
Dim contents As String
objReader = New IO.StreamReader("testfile.csv")
contents = objReader.ReadToEnd()
objReader.Close()
Dim objWriter As New System.IO.StreamWriter("testfile.csv")
MsgBox(contents)
'contents = Replace(contents, vbCr, "")
contents = Replace(contents, vbLf, "")
MsgBox(contents)
objWriter.Write(contents)
objWriter.Close()
'
Dts.TaskResult = ScriptResults.Success
End Sub
I forgot to mention that the input file name changes daily, How do I code so it doesn't care for the file name as long as it as a CSV file? So testfile name has current date and changes daily. I've tried just the file path and it errored out as well. Used the *.csv and it didnt like that either.
objReader = New IO.StreamReader("\FolderA\FolderB\TestFile09212022.csv")
If you are sure there are no double quotes text inside the double quotes you can do it like this:
Dim sNewString As String = ""
Dim s As String
Dim bFirstQuoted As Boolean = False
Dim i As Integer
Dim objWriter As New System.IO.StreamWriter("testfile.csv")
MsgBox(contents)
For i = 1 To contents.Length
s = Mid(contents, i, 1)
If s = """" Then bFirstQuoted = Not bFirstQuoted
If Not bFirstQuoted OrElse (s <> vbLf AndAlso bFirstQuoted) Then
sNewString += s
else
sNewString += " "
End If
Next
MsgBox(sNewString )
objWriter.Write(sNewString )
objWriter.Close()
Dts.TaskResult = ScriptResults.Success
I am reading records from a SQL Server table into a dataset and then exporting it to a CSV file. When I step through it in debug mode, everything works fine. When I run it, it exports just one cell with crap data. Since it is an ASP.NET application I am not sure if I am doing something wrong regarding postbacks. It seems in run-time, it doesn't wait for the CSV file to be written.
Dim sbldRecordCSV As New StringBuilder
Dim dtHCMTable As DataTable = mdsHCMTable.Tables(0)
Dim intIndex As Integer = 0
'Read the connection-string from web.config
Dim connHCM As New SqlConnection(System.Configuration.ConfigurationManager.ConnectionStrings("connHCM").ConnectionString)
'Read the exported CSV file path from web.config
Dim strCSVpath As String = System.Configuration.ConfigurationManager.AppSettings("CSVpath").ToString
Try
For intIndex = 0 To mdsHCMTable.Tables(0).Rows.Count - 1
Dim drHCMTable As DataRow = dtHCMTable.Rows(intIndex)
For Each field As Object In drHCMTable.ItemArray
sbldRecordCSV.Append(field.ToString & "|")
Next
sbldRecordCSV.Replace("|", vbNewLine, sbldRecordCSV.Length - 1, 1)
Next
My.Computer.FileSystem.WriteAllText(strCSVpath.ToString & lstDataTables.SelectedValue.ToString & ".csv", sbldRecordCSV.ToString, False)
After some searching around I realized that I neede to modify the ExportCSV code. The modified routine is as follows:
Protected Sub ExportToCSV(mdsHCMTable As DataSet)
Dim dt As DataTable = mdsHCMTable.Tables(0)
'Read the exported CSV file path from web.config
Dim strCSVpath As String = System.Configuration.ConfigurationManager.AppSettings("CSVpath").ToString
Response.Clear()
Response.Buffer = True
Response.AddHeader("content-disposition", "attachment;filename=" & lstDataTables.SelectedValue.ToString & ".csv")
Response.Charset = ""
Response.ContentType = "application/text"
Dim sb As New StringBuilder()
For k As Integer = 0 To dt.Columns.Count - 1
'add separator
sb.Append(dt.Columns(k).ColumnName + "|"c)
Next
'append new line
sb.Append(vbCr & vbLf)
For i As Integer = 0 To dt.Rows.Count - 1
For k As Integer = 0 To dt.Columns.Count - 1
'add separator
sb.Append(dt.Rows(i)(k).ToString().Replace(",", "|") + "|"c)
Next
'append new line
sb.Append(vbCr & vbLf)
Next
Response.Clear()
Response.BufferOutput = False
Response.Output.Write(sb.ToString())
Response.Flush()
End Sub
This solution worked for me. I hope it can be helpful to others.
I have a simple program that reads a .txt file, and then splits it up into many files of "pMaxRows" number of rows. These .txt files are huge - some are nearly 25Gb. Right now it is not running fast enough for my liking, I feel that there should be a way to improve the efficiency by maybe reading/writing multiple lines at once, but I am not very experienced with vb.net streamreader/streamwriter.
Code is below:
Public Sub Execute(ByVal pFileLocation As String, _
ByVal pMaxRows As Int32)
Dim sr As IO.StreamReader
Dim Row As String
Dim SourceRowCount As Int64
Dim TargetRowCount As int64
Dim TargetFileNumber As Int32
''Does the file exist in that location?
If IO.File.Exists(pFileLocation) = False Then
Throw New Exception("File does not exist at " & pFileLocation)
End If
''Split FileLocation into FileName and Folder Location
Dim arrFileLoc() As String = pFileLocation.Split("\")
Dim i As Integer = arrFileLoc.Length - 1
Dim FileName As String = arrFileLoc(i)
Dim FileLocationLength As Integer = pFileLocation.Length
Dim FileNameLength As Integer = FileName.Length
Dim Folder As String = pFileLocation.Remove(FileLocationLength - FileNameLength, FileNameLength)
''Read the file
sr = New IO.StreamReader(pFileLocation)
SourceRowCount = 0
TargetRowCount = 0
TargetFileNumber = 1
''Create First Target File Name
Dim TargetFileName As String
TargetFileName = TargetFileNumber & "_" & FileName
''Open streamreader and start reading lines
Do While Not sr.EndOfStream
''if it hits the target number of rows:
If (TargetRowCount = pMaxRows) Then
''Advance target file number
TargetFileNumber += 1
''Create New file with target file number
TargetFileName = TargetFileNumber & "_" & FileName
''Set target row count back to 0
TargetRowCount = 0
End If
''Read line
Row = sr.ReadLine()
''Write line
Using sw As New StreamWriter(Folder & TargetFileName, True)
sw.WriteLine(Row)
End Using
SourceRowCount += 1
TargetRowCount += 1
Loop
End Sub
Anyone have any suggestions? Even directing me to the right place if this has been answered before would be much appreciated
So to start this is the code I have already written:
Dim MyFile As String = "Path"
Dim str_new As String
Dim str_old As String = File.ReadAllText(MyFile)
Dim sr As New StreamReader(MyFile)
Dim strLines As String() = Strings.Split(sr.ReadToEnd, Environment.NewLine)
Dim Character As Integer = 5 'Line 1 always has 5 characters
For i = 2 To strLines.Length
Dim PreviousLine As String = sr.ReadLine(i - 1)
Dim CurrentLine As String = sr.ReadLine(i)
If CurrentLine.Contains(TextBox1.Text / 100) Then
If PreviousLine.Contains("divide") Then
Exit For
End If
End If
Character = Character + CurrentLine.Length
Next
sr.Close()
str_new = Replace(str_old, (TextBox1.Text / 100), (TextBox3.Text / 100), Character, 1)
Dim objWriter3 As New System.IO.StreamWriter(MyFile, False)
objWriter3.Write(str_new)
objWriter3.Flush()
objWriter3.Close()
I am trying to figure out a way to break a long code file into lines then check each line for certain strings. If the current line contains the string then I will do additional check on above and/or below lines to make sure This is the correct instance of the string. Finally I want to replace just that instance of the string with a different string.
An example: text file
class
...
0.3
divide <-- Previous Line
0.3 <-- TextBox1.Text is 30
.5
end
I want the code to go past the first instance of 0.3
Find the second instance
Check previous line for divide
Exit Loop
Replace second instance of 0.3 to some value
I have been looking into this for a while now and any help would be greatly appreciated!
~Matt
Revised: Code
Dim MyFile As String = "Path"
Dim NewFile As String = "Temporary Path"
Dim PreviousLine As String = ""
Dim CurrentLine As String = ""
Using sr As StreamReader = New StreamReader(MyFile)
Using sw As StreamWriter = New StreamWriter(NewFile)
CurrentLine = sr.ReadLine
Do While (Not CurrentLine Is Nothing)
Dim LinetoWrite = CurrentLine
If CurrentLine.Contains(TextBox1.Text) Then
If PreviousLine.Contains("divide") Then
LinetoWrite = Replace(CurrentLine, TextBox1.Text, TextBox3.Text)
End If
End If
sw.WriteLine(LinetoWrite)
PreviousLine = CurrentLine
CurrentLine = sr.ReadLine
Loop
End Using
End Using
My.Computer.FileSystem.CopyFile(NewFile, MyFile, True)
You are facing the problem in the wrong way. You have to set both, reader and writer, and generate a new file with all the modifications. Your code has various parts which should be improved; in this answer, I am just showing how to use StreamReader/StreamWriter properly. Sample code:
Dim MyFile As String = "input path"
Dim OutputFile As String = "output path"
Dim PreviousLine As String = ""
Dim CurrentLine As String = ""
Using sr As StreamReader = New StreamReader(MyFile)
Using sw As StreamWriter = New StreamWriter(OutputFile)
CurrentLine = sr.ReadLine
Do While (Not CurrentLine Is Nothing)
Dim lineToWrite = CurrentLine
'Perform the analysis you wish by involving the current line, the previous one and as many other (previous) lines as you wish; and store the changes in lineToWrite. You should call a function here to perform this analysis
sw.WriteLine(lineToWrite) 'Writing lineToWrite to the new file
PreviousLine = CurrentLine 'Future previous line
CurrentLine = sr.ReadLine 'Reading the line for the next iteration
Loop
End Using
End Using
Does anybody have VB code to emulate Streamwriter for Windows Store?
I know it's been replaced by StorageFolder class but there is no VB sample in MSDN and I can't seem to translate properly from c# examples. Any help would be appreciated. I am just trying to write text (CSV) to a file and save it to the documents folder. In the code below windows store want a stream instead of strPath when I try dim-ing a streamwriter. (been playing with pickerdialog too, but that might be the next hurdle).
Dim strpath As String = Windows.Storage.Pickers.PickerLocationId.DocumentsLibrary & "\" & strFileName
'Build String for file*******************
Dim swExport As StreamWriter = New StreamWriter(strpath)
swExport.Flush()
For x = 0 To intCount - 1
strLine = "WriteSomeText"
swExport.WriteLine(strLine)
Next x
Possibly the simplest approach would be to use a MemoryStream if you like StreamWriter, so something like:
Dim sessionData As New MemoryStream()
' TODO: stage data in sessionData
Dim swExport As StreamWriter = New StreamWriter(sessionData)
swExport.Flush()
For x = 0 To intCount - 1
strLine = "WriteSomeText"
swExport.WriteLine(strLine)
Next x
Dim file As StorageFile = await ApplicationData.Current.RoamingFolder.CreateFileAsync("towns.json", CreationCollisionOption.ReplaceExisting)
Using (fileStream As Stream = await file.OpenStreamForWriteAsync())
sessionData.Seek(0, SeekOrigin.Begin)
await sessionData.CopyToAsync(fileStream)
await fileStream.FlushAsync()
End Using
I was making it too difficult. To write to a file I just needed to use storagefolder and storagefile. I have also included the FileSavePicker in the code (note that filetypechoices is mandatory)
Private Async Function btnExport_Click(sender As Object, e As RoutedEventArgs) As Task
'Calls Filepicker to determine location
'Calls Sqlite to select ALL
'Creates CSV file to be saved at location chosen
'save to file
Dim intCount As Integer = "5"
Dim x As Integer
Dim strLine As String 'hold each line for export file
'Create FileName based on date
Dim strDate As String = Date.Today.ToString("MMddyyyy")
Dim strFileName As String = "Export" & strDate & ".csv"
' Configure save file dialog box
Dim dlgPicker As New Windows.Storage.Pickers.FileSavePicker
'add types for picker (manditory field)
Dim types = New List(Of String)
types.Add(".csv")
types.Add(".txt")
'set picker parameters
dlgPicker.SuggestedStartLocation = Windows.Storage.Pickers.PickerLocationId.Downloads
dlgPicker.SuggestedFileName = strFileName '"Document" '
dlgPicker.FileTypeChoices.Add("CSV/TXT", types) 'manditory
dlgPicker.DefaultFileExtension = ".csv" 'Filter files by extension
dlgPicker.CommitButtonText = "Save"
' Show save file dialog box
Dim SaveCSV = Await dlgPicker.PickSaveFileAsync()
'************************get data************
Dim sbExport As Text.StringBuilder = New Text.StringBuilder
sbExport.AppendLine(strHeader)
For x = 0 To intCount - 1
strLine = "Get the text you want to write here"
sbExport.AppendLine(strLine)
Next x
'************************************
'write data to file
Await FileIO.WriteTextAsync(SaveCSV, sbExport.ToString)
Dim mb As MessageDialog = New MessageDialog("Done")
Await mb.ShowAsync()
End Function