Convert text file data to Hex file data.

Question

Hello,

I have a hex listing in a text file that is 14 bytes long...

40 00 78 7B 7A

These are characters. The hex values are...

34 30 20
30 30 20
37 38 20
37 42 20
37 61

How do I go about converting this to a file containing only hex values? The resulting file should contain only 5 bytes...

4000787B7A

Thank you in advance,

ED

Answer 1

Public Class Form1

 

    Private Sub Button1_Click(ByVal sender As System.Object, _

    ByVal e As System.EventArgs) Handles Button1.Click

        ' Where test3.fil contains the text:

        ' 3430203030203738203742203761

        Dim i As Integer

        Dim j As String = ""

        Dim st As String = ""

        Dim s() As Byte = System.IO.File.ReadAllBytes("c:\test3.fil")

        Dim r(s.Length) As Char

        For x As Integer = 0 To s.Length - 1

            i = CType(s(x), Integer)

            st = st + Chr(i)

        Next

        st = st.Replace("20", "")

        For i = 1 To st.Length Step 2

            Dim g As Integer = CInt(Mid(st, i, 2))

            j = j + Chr(Convert.ToInt32(g.ToString, 16))

        Next

        ' Your result in a msgbox

        MsgBox(j)

    End Sub

 

 

End Class

 

Answer 2

Hello,

Thanks for the sample.

I was having a problem with your code when getting to a value that contained a letter (e.g.: 7B).

I modified your sample, and using brute force, I was able to get it working using two select/case blocks. Here is the code I put together.

Public Class Form1
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim i As Integer
Dim j As String = ""
Dim st As String = ""
Dim s() As Byte = System.IO.File.ReadAllBytes("c:\b.txt")
Dim r(s.Length) As Char
Dim hextemp As Integer
Dim hexstring1 As String
Dim hexstring2 As String
Dim hexdata() As Byte
Dim count As Integer = -1

For x As Integer = 0 To s.Length - 1
    i = CType(s(x), Integer)
    st = st + Chr(i)
    Next
st = st.Replace(" ", "")

For i = 1 To st.Length Step 2
    count += 1
    ReDim Preserve hexdata(count)
    hexstring1 = Mid(st, i, 1)
    hexstring2 = Mid(st, i + 1, 1)
    Select Case hexstring1
        Case "0" : hextemp = &H0
        Case "1" : hextemp = &H10
        Case "2" : hextemp = &H20
        Case "3" : hextemp = &H30
        Case "4" : hextemp = &H40
        Case "5" : hextemp = &H50
        Case "6" : hextemp = &H60
        Case "7" : hextemp = &H70
        Case "8" : hextemp = &H80
        Case "9" : hextemp = &H90
        Case "A" : hextemp = &HA0
        Case "B" : hextemp = &HB0
        Case "C" : hextemp = &HC0
        Case "D" : hextemp = &HD0
        Case "E" : hextemp = &HE0
        Case "F" : hextemp = &HF0
        End Select
    Select Case hexstring2
        Case "0" : hextemp += &H0
        Case "1" : hextemp += &H1
        Case "2" : hextemp += &H2
        Case "3" : hextemp += &H3
        Case "4" : hextemp += &H4
        Case "5" : hextemp += &H5
        Case "6" : hextemp += &H6
        Case "7" : hextemp += &H7
        Case "8" : hextemp += &H8
        Case "9" : hextemp += &H9
        Case "A" : hextemp += &HA
        Case "B" : hextemp += &HB
        Case "C" : hextemp += &HC
        Case "D" : hextemp += &HD
        Case "E" : hextemp += &HE
        Case "F" : hextemp += &HF
        End Select
    hexdata(count) = hextemp
    Next
System.IO.File.WriteAllBytes("c:\b.hex", hexdata)
End Sub
End Class

I'm sure there is a way to simplify the Select statements but it works.

Thanks again,

ED

Answer 3

You may wish to take a look at the hex function:

(from the object browser)

Public Shared Function Hex(ByVal Number As Integer) As String

Member of Microsoft.VisualBasic.Conversion

Summary:

Returns a string representing the hexadecimal value of a number.

Parameters:

Number: Required. Any valid numeric expression or String expression.

Return Values:

Returns a string representing the hexadecimal value of a number.

Public Shared Function Hex(ByVal Number As Byte) As String

Member of Microsoft.VisualBasic.Conversion

Summary:

Returns a string representing the hexadecimal value of a number.

Parameters:

Number: Required. Any valid numeric expression or String expression.

Return Values:

Returns a string representing the hexadecimal value of a number.

Answer 4

Hello,

Thanks for the tip.

I looked at the Hex function, but it is used to convert a number to the string representation:

hex(123)
"7B"

I did find ToByte. It does just what I need. Your tip pointed the way. Here is the code as it now stands.

Public Class Form1
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim i As Integer
Dim st As String = ""
Dim s() As Byte = System.IO.File.ReadAllBytes("c:\b.txt")
Dim hextemp As Integer
Dim hexstring1 As String
Dim hexdata() As Byte
Dim count As Integer = -1

For x As Integer = 0 To s.Length - 1
    i = CType(s(x), Integer)
    st = st + Chr(i)
    Next

st = st.Replace(" ", "")

For i = 1 To st.Length Step 2
    count += 1
    ReDim Preserve hexdata(count)
    hexstring1 = Mid(st, i, 2)
    hextemp = Convert.ToByte(hexstring1, 16)
    hexdata(count) = hextemp
    Next
System.IO.File.WriteAllBytes("c:\b.hex", hexdata)
End Sub
End Class

Thanks for the help guys,

ED