41 lines
1.1 KiB
Plaintext
41 lines
1.1 KiB
Plaintext
' FB 1.05.0 Win64
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' uses same alphabet and key as Ada language example
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Const string1 = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"
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Const string2 = "VsciBjedgrzyHalvXZKtUPumGfIwJxqOCFRApnDhQWobLkESYMTN"
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Sub process(inputFile As String, outputFile As String, encrypt As Boolean)
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Open inputFile For Input As #1
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If err > 0 Then
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Print "Unable to open input file"
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Sleep
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End
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End If
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Dim As String alpha, key
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If encrypt Then
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alpha = string1 : key = string2
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Else
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alpha = string2 : key = string1
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End If
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Open outputFile For Output As #2
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Dim s As String
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Dim p As Integer
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While Not Eof(1)
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Line Input #1, s
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For i As Integer = 0 To Len(s) - 1
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If (s[i] >= 65 AndAlso s[i] <= 90) OrElse (s[i] >= 97 AndAlso s[i] <= 122) Then
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p = Instr(alpha, Mid(s, i + 1, 1)) - 1
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s[i] = key[p]
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End If
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Next
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Print #2, s
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Wend
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Close #1 : Close #2
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End Sub
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process "plain.txt", "encrypted.txt", true
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process "encrypted.txt", "decrypted.txt", false
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Print
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Print "Press any key to quit"
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Sleep
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