[Gambas-user] Base 64 question
Fabien Bodard
gambas.fr at ...626...
Fri Apr 29 08:19:55 CEST 2011
2011/4/28 Caveat <Gambas at ...1950...>:
> xml.Decode...pfft! Funny, I never would have thought to look in gb.xml
> for a base64 decoder!
true ... i've found it in the past when i've made a little program to
extract mail attachement in old mail directories
> Anyhoo, did you compare xml.Decode and the routine below with the decode
> function I wrote in the example project I sent earlier... or are you
> *still* waiting for my decode function to return a result? lol
>
> I'm wondering if the Wait is doing much useful in the subroutine below
> (in theory it should be allowing processing of all pending events, but
> no user interaction). Perhaps you could remove it and see what
> happens...
>
> Regards,
> Caveat
>
> On Thu, 2011-04-28 at 22:09 +1000, richard terry wrote:
>> On Thursday 28 April 2011 21:50:55 richard terry wrote:
>>
>> I've tried them both the xml reader and the subroutine below, on a real-life
>> file, a hl7 file containg a pdf of a vascular result
>>
>> this code written by
>> Christer Nygren <petterfilip at ...626...> and some others,
>>
>> on my machine seems considerably faster than the xml.decode function
>>
>> Public Sub FromB64(B64Str As String) As String
>> Dim Position As Long
>> Dim dt As Byte
>> Dim B64Decoded, u, c As String
>> Dim Tkn, p As Integer
>>
>> Position = 1
>> Tkn = 0
>> Do Until Position > Len(B64Str)
>> Wait
>> c = Mid(B64Str, Position, 1)
>> p = InStr(B64Const, c)
>> If p > 1 Then
>> p = p - 2
>> Inc Tkn
>> Select Case Tkn
>> Case 1
>> dt = (p * &h4)
>> Case 2
>> B64Decoded = B64Decoded & Chr(dt + ((p And &H30&) / &H10&))
>> dt = (p And &HF&) * &H10&
>> Case 3
>> B64Decoded = B64Decoded & Chr(dt + ((p And &H3C&) / 4))
>> dt = (p And &H3&) * &H40&
>> Case 4
>> B64Decoded = B64Decoded & Chr(dt + p)
>> End Select
>> If Tkn = 4 Then Tkn = 0
>> Else ' Ej skrivbart tecken
>> If p = 1 Then
>> Position = Len(B64Str) + 1
>> End If
>> Endif
>> Inc Position
>> Loop
>> Select Case Tkn
>> Case 1
>> B64Decoded = B64Decoded & Chr(dt)
>> End Select
>> Return B64Decoded
>> End
>>
>> ??coments from those who know?
>>
>> richard
>>
>>
>> > On Thursday 28 April 2011 21:38:52 Fabien Bodard wrote:
>> > > Print XmlReader.Decode("strvalue", "Base64")
>> >
>> > Funny that, I based my head against a wall trying exactly that syntax, I
>> > eventually found some old gambas code on the web that worked.
>> >
>> > But... just typed it in again, and it works. Dunno......... maybe I didn't
>> > capitalise it or something.
>> >
>> > Anway, thanks.
>> >
>> > Like everything else in gambas, blindingly simple if you know.
>> >
>> >
>> > Richard
>> >
>> > > 2011/4/28 richard terry <rterry at ...1946...>:
>> > > > On Thursday 28 April 2011 20:16:31 Fabien Bodard wrote:
>> > > > I tried this:
>> > > > XmlReader.Decode(data, "?????"
>> > > >
>> > > > what goes in the encoding type "?????"
>> > > >
>> > > > I looked on the website to no avail
>> > > > I tried strings like "Base64", "base64" etc
>> > > >
>> > > > couldn't figure it out.
>> > > >
>> > > > any hlep appreciated.
>> > > >
>> > > > Richard
>> > > >
>> > > >> gb.xml !
>> > > >>
>> > > >> 2011/4/28 Caveat <Gambas at ...1950...>:
>> > > >> > Hi Richard,
>> > > >> >
>> > > >> > I don't know of any base64 decode function in Gambas, but then I
>> > > >> > didn't look that hard ;-)
>> > > >> >
>> > > >> > There are various different flavours of base64, so be sure you know
>> > > >> > which variant you're dealing with.
>> > > >> >
>> > > >> > I enclose with this mail a source archive of a little project I've
>> > > >> > put together (sorry, it's Gambas2, hope that's OK) that demonstrates
>> > > >> > decoding (and encoding) of base64 data. I found the information on
>> > > >> > how to put together the encode and decode algorithms here:
>> > > >> > http://en.wikipedia.org/wiki/Base64
>> > > >> >
>> > > >> > There's also a reference to base64 in Gambas here:
>> > > >> > http://www.gambasforum.com/index.php?topic=330.0
>> > > >> > The algorithms given in those code snippets could well be far more
>> > > >> > efficient than mine.
>> > > >> >
>> > > >> > My Base64 Project
>> > > >> > -----------------
>> > > >> > First thing to try is just hit the Encode button, it should convert
>> > > >> > the text in the top textarea into base64 and place the result in the
>> > > >> > lower textarea. Generally, if the In textbox is blank, the input for
>> > > >> > Encode or Decode will be the upper textarea, and if the Out textbox
>> > > >> > is blank, the output of the Encode or Decode will be shown in the
>> > > >> > lower textarea. To encode binary data, you'll need to use a file as
>> > > >> > input, so use the In textbox to specify the file name. To decode
>> > > >> > base64 that represents binary data, you'll need to use a file as
>> > > >> > output, so use the Out textbox to specify the output file name.
>> > > >> >
>> > > >> > You can try out binary to base64 using fluffy.jpg (shipped with the
>> > > >> > project) as your In file.
>> > > >> >
>> > > >> > To test round-trip (so start with a binary, encode it to base64,
>> > > >> > then decode the base64 data to make an identical binary)... enter
>> > > >> > fluffy.jpg in the In textbox, blank the Out textbox, hit Encode. In
>> > > >> > the lower textarea Select All, Copy... then in the upper textarea
>> > > >> > Paste. Now clear the In textbox and enter coffee.jpg in the Out
>> > > >> > textbox. Hit Decode. You *should* find a new file in your Base64
>> > > >> > project directory called coffee.jpg, and it *should* be identical to
>> > > >> > the fluffy.jpg shipped with the project.
>> > > >> >
>> > > >> > I'm not convinced that my completely untuned, horribly inefficient
>> > > >> > algorithms in Gambas will be the best way to go if speed is of the
>> > > >> > essence or if the pdf files are gonna be more than a few 100 kbs...
>> > > >> > you might find it quicker/more robust to call out to a built-in
>> > > >> > function in java/python/some other program...
>> > > >> >
>> > > >> > Anyways, all the (commented) source is there for you to see/fiddle
>> > > >> > with...so have fun, but if you have any questions, just give me a
>> > > >> > shout.
>> > > >> >
>> > > >> > Regards,
>> > > >> > Caveat
>> > > >> >
>> > > >> > On Thu, 2011-04-28 at 07:38 +1000, Ian Haywood wrote:
>> > > >> >> No, HL7 parsing is fine, let me restate the question: does gambas
>> > > >> >> have an inbuilt function to
>> > > >> >> decode base 64 data?
>> > > >> >>
>> > > >> >> Ian
>> > > >> >>
>> > > >> >> On Thu, Apr 28, 2011 at 3:48 AM, nando <nando_f at ...951...>
>> >
>> > wrote:
>> > > >> >> > Health Level 7 file format
>> > > >> >> > To start visit:
>> > > >> >> > http://en.wikipedia.org/wiki/Health_Level_7
>> > > >> >> >
>> > > >> >> >
>> > > >> >> > ---------- Original Message -----------
>> > > >> >> > From: richard terry <rterry at ...1946...>
>> > > >> >> > To: mailing list for gambas users
>> > > >> >> > <gambas-user at lists.sourceforge.net> Sent: Wed, 27 Apr 2011
>> > > >> >> > 18:13:57 +1000
>> > > >> >> > Subject: [Gambas-user] Base 64 question
>> > > >> >> >
>> > > >> >> >> Hi list,
>> > > >> >> >>
>> > > >> >> >> I've a HL7 file apparently with embedded base64 data (as a pdf)
>> > > >> >> >> I wondered if there iwas any way to de-encode the data, if that
>> > > >> >> >> is the right syntax.
>> > > >> >> >>
>> > > >> >> >> Regards
>> > > >> >> >>
>> > > >> >> >> Richard
>> > > >> >> >>
>> > > >> >> >> ----------------------------------------------------------------
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>> > > >> >> >> _______________________________________________
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>> > > >> >> >
>> > > >> >> > ------- End of Original Message -------
>> > > >> >> >
>> > > >> >> >
>> > > >> >> > -----------------------------------------------------------------
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>> > > >> >> > Software The most intuitive, comprehensive, and cost-effective
>> > > >> >> > network management toolset available today. Delivers lowest
>> > > >> >> > initial acquisition cost and overall TCO of any competing
>> > > >> >> > solution. http://p.sf.net/sfu/whatsupgold-sd
>> > > >> >> > _______________________________________________
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>> > > >> >>
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>> > > >> >> network management toolset available today. Delivers lowest
>> > > >> >> initial acquisition cost and overall TCO of any competing solution.
>> > > >> >> http://p.sf.net/sfu/whatsupgold-sd
>> > > >> >> _______________________________________________
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>> > > >> >
>> > > >> > --------------------------------------------------------------------
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>> > > >> > The most intuitive, comprehensive, and cost-effective network
>> > > >> > management toolset available today. Delivers lowest initial
>> > > >> > acquisition cost and overall TCO of any competing solution.
>> > > >> > http://p.sf.net/sfu/whatsupgold-sd
>> > > >> > _______________________________________________
>> > > >> > Gambas-user mailing list
>> > > >> > Gambas-user at lists.sourceforge.net
>> > > >> > https://lists.sourceforge.net/lists/listinfo/gambas-user
>> > > >
>> > > > -----------------------------------------------------------------------
>> > > >-- ----- WhatsUp Gold - Download Free Network Management Software
>> > > > The most intuitive, comprehensive, and cost-effective network
>> > > > management toolset available today. Delivers lowest initial
>> > > > acquisition cost and overall TCO of any competing solution.
>> > > > http://p.sf.net/sfu/whatsupgold-sd
>> > > > _______________________________________________
>> > > > Gambas-user mailing list
>> > > > Gambas-user at lists.sourceforge.net
>> > > > https://lists.sourceforge.net/lists/listinfo/gambas-user
>> >
>> > ---------------------------------------------------------------------------
>> > --- WhatsUp Gold - Download Free Network Management Software
>> > The most intuitive, comprehensive, and cost-effective network
>> > management toolset available today. Delivers lowest initial
>> > acquisition cost and overall TCO of any competing solution.
>> > http://p.sf.net/sfu/whatsupgold-sd
>> > _______________________________________________
>> > Gambas-user mailing list
>> > Gambas-user at lists.sourceforge.net
>> > https://lists.sourceforge.net/lists/listinfo/gambas-user
>> >
>>
>> ------------------------------------------------------------------------------
>> WhatsUp Gold - Download Free Network Management Software
>> The most intuitive, comprehensive, and cost-effective network
>> management toolset available today. Delivers lowest initial
>> acquisition cost and overall TCO of any competing solution.
>> http://p.sf.net/sfu/whatsupgold-sd
>> _______________________________________________
>> Gambas-user mailing list
>> Gambas-user at lists.sourceforge.net
>> https://lists.sourceforge.net/lists/listinfo/gambas-user
>
>
>
> ------------------------------------------------------------------------------
> WhatsUp Gold - Download Free Network Management Software
> The most intuitive, comprehensive, and cost-effective network
> management toolset available today. Delivers lowest initial
> acquisition cost and overall TCO of any competing solution.
> http://p.sf.net/sfu/whatsupgold-sd
> _______________________________________________
> Gambas-user mailing list
> Gambas-user at lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/gambas-user
>
--
Fabien Bodard
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