Replacing a string inside of a PDF

[Josh Baltzell]

I am having a lot more trouble with this than I thought I would. Here
is what I want to do in pseudocode.

Open c:\some.pdf
Replace "Replace this" with "Replaced!"
Save c:\some_edited. pdf

I can do this in notepad and it works fine, but when I start getting in
to reading the files I think it has some encoding problem. I tried
saving the file with every encoding option. When I open a PDF in the
text editor I normally use it says it is ANSI with Mac style carriage
returns. Winmerge will not let me compare the files because it says
they are binary.

Anyone know what I have to do?

[Samuel Shulman]

Finally,
Can you achieve what you actually need?

Samuel
"Josh Baltzell" <jo**********@g mail.comwrote in message
news:11******** **************@ i42g2000cwa.goo glegroups.com.. .

Here is another test I wrote that sucessfully generates a bunch of
useless files encoded in different ways.

::::::::::::::: ::::::::::::::: ::::::::::::::: ::::::::::::::: :
Public Function StringTest()
Dim PDFFile As String
Dim PDFFolder As IO.Directory

Response.Write( "Start String:" & DateTime.Now.To LongTimeString
& ":" & Now.Millisecond & "<br>")

For Each PDFFile In PDFFolder.GetFi les(Server.MapP ath("PDF"))
'Open the file
Dim FileStream As IO.StreamReader
FileStream = IO.File.OpenTex t(PDFFile)

'Load the file in to a string
Dim Contents As String = FileStream.Read ToEnd

'Replace text in string
Contents = Contents.Replac e("ABC123456789 0",
"ABC1111111111" )

'Close stream
FileStream.Clos e()

'Create ASCII output file
Dim OutputFileName As String = Server.MapPath( "PDFOutput\ "
& DateTime.Now.To FileTimeUtc.ToS tring & "STRING-ASCII.pdf")
Dim fs As FileStream = File.Create(Out putFileName)
Dim PDFStream As StreamWriter = New StreamWriter(fs ,
System.Text.Enc oding.ASCII)
PDFStream.Write (Contents)
PDFStream.Close ()
fs.Close()

'Create BigEndianUnicod e output file
OutputFileName = Server.MapPath( "PDFOutput\ " &
DateTime.Now.To FileTimeUtc.ToS tring & "STRING-BigEndianUnicod e.pdf")
fs = File.Create(Out putFileName)
PDFStream = New StreamWriter(fs ,
System.Text.Enc oding.BigEndian Unicode)
PDFStream.Write (Contents)
PDFStream.Close ()
fs.Close()

'Create default formatted output file
OutputFileName = Server.MapPath( "PDFOutput\ " &
DateTime.Now.To FileTimeUtc.ToS tring & "STRING-Default.pdf")
fs = File.Create(Out putFileName)
PDFStream = New StreamWriter(fs ,
System.Text.Enc oding.Default)
PDFStream.Write (Contents)
PDFStream.Close ()
fs.Close()

'Create Unicode output file
OutputFileName = Server.MapPath( "PDFOutput\ " &
DateTime.Now.To FileTimeUtc.ToS tring & "STRING-Unicode.pdf")
fs = File.Create(Out putFileName)
PDFStream = New StreamWriter(fs ,
System.Text.Enc oding.Unicode)
PDFStream.Write (Contents)
PDFStream.Close ()
fs.Close()

'Create UTF7 output file
OutputFileName = Server.MapPath( "PDFOutput\ " &
DateTime.Now.To FileTimeUtc.ToS tring & "STRING-UTF7.pdf")
fs = File.Create(Out putFileName)
PDFStream = New StreamWriter(fs , System.Text.Enc oding.UTF7)
PDFStream.Write (Contents)
PDFStream.Close ()
fs.Close()

'Create UTF8 output file
OutputFileName = Server.MapPath( "PDFOutput\ " &
DateTime.Now.To FileTimeUtc.ToS tring & "STRING-UTF8.pdf")
fs = File.Create(Out putFileName)
PDFStream = New StreamWriter(fs , System.Text.Enc oding.UTF8)
PDFStream.Write (Contents)
PDFStream.Close ()
fs.Close()

Next

Response.Write( "Stop String:" & DateTime.Now.To LongTimeString &
":" & Now.Millisecond & "<br>")

End Function
::::::::::::::: ::::::::::::::: ::::::::::::::: ::::::::::::::: :

[Branco Medeiros]

Josh Baltzell wrote:

I am having a lot more trouble with this than I thought I would. Here
is what I want to do in pseudocode.

Open c:\some.pdf
Replace "Replace this" with "Replaced!"
Save c:\some_edited. pdf

I can do this in notepad and it works fine, but when I start getting in
to reading the files I think it has some encoding problem. I tried
saving the file with every encoding option. When I open a PDF in the
text editor I normally use it says it is ANSI with Mac style carriage
returns. Winmerge will not let me compare the files because it says
they are binary.

<snip>

Winmerge is right, a PDF file is actually a binary image, not a plain
text in a given encoding. You should load it as a stream of bytes.

On the other hand, since you want to perform text replacements in the
file, you may load it with an encoding that doesn't apply
transformations on the bytes in the file, such as the Ansi encoding:

Sub PDFReplaceText( ByVal Path As String, ByVal OldText As String, _
ByVal OutPath As String, ByVal NewText As String)

Const ANSI As Integer = 1252

Dim Encoding As Text.Encoding = Text.Encoding.G etEncoding(ANSI )
Dim sr As New IO.StreamReader (Path, Encoding)
Dim Data As String = sr.ReadToEnd
sr.Close()

Data = Data.Replace(Ol dText, NewText)

Dim sw As New IO.StreamWriter (OutPath, False, Encoding)
sw.Write(Data)
sw.Close()

End Sub

HTH.

Regards,

Branco.

[Josh]

Branco,

This worked perfect. My knowlege about the encoding options in general
is very weak, so thanks for spelling it out for me with some code.

Samuel,

Thank you to you too. You have both been a big help.

Thank you,
Josh Baltzell

[Samuel Shulman]

I am glad to hear,

Is Branco's code works as is?
"Josh" <jo**********@g mail.comwrote in message
news:11******** **************@ 75g2000cwc.goog legroups.com...

Branco,

This worked perfect. My knowlege about the encoding options in general
is very weak, so thanks for spelling it out for me with some code.

Samuel,

Thank you to you too. You have both been a big help.

Thank you,
Josh Baltzell

[Josh]

I put the encoding options in to my own code, so I am not positive.
This is the final sub I ended up with.

Public Sub ReplaceText(ByV al FilePath As String, ByVal OriginalText
As String, ByVal NewText As String)
Dim PDFFolder As IO.Directory
Dim Encoding As System.Text.Enc oding =
Encoding.GetEnc oding(1252)

'Open the file
Dim FileStream As New IO.StreamReader (FilePath, Encoding)

'Load the file in to a string
Dim Contents As String = FileStream.Read ToEnd

'Replace text in string
Contents = Contents.Replac e(OriginalText, NewText)

'Close stream
FileStream.Clos e()

'Write string as bytes to output file
Dim OutputFileName As String = FilePath
Dim sw As New IO.StreamWriter (OutputFileName , False, Encoding)
sw.Write(Conten ts)
sw.Close()

End Sub

Samuel Shulman wrote:

I am glad to hear,

Is Branco's code works as is?
"Josh" <jo**********@g mail.comwrote in message
news:11******** **************@ 75g2000cwc.goog legroups.com...

Branco,

This worked perfect. My knowlege about the encoding options in general
is very weak, so thanks for spelling it out for me with some code.

Samuel,

Thank you to you too. You have both been a big help.

Thank you,
Josh Baltzell