Topic: Read and Write PIA Files

[kaefer]

The same procedure as every couple of years : After IT migrated to new servers, all PC3-saved printer paths are invalid. Either that or there are other reasons to read and write the special format in which AutoCAD's plotter support files are saved.

First, here's a short description of the PIA (whatever that may stand for) file format.
Secondly, since Zlib streams aren't part of the runtime, I needed to download the dotnetzip library, in order to reference zlib-v1.9\Ionic.Zlib.dll.

Code - F#: [Select]

type System.IO.Stream with
    member me.WriteString (s : string) =
        let buf = s.ToCharArray() |> Array.map byte
        me.Write(buf, 0, buf.Length)
 
module Zlib = 
    open System.IO
    open Ionic.Zlib
 
    let read fileName = 
        use fs = File.Open(fileName, FileMode.Open, FileAccess.Read)
        fs.Seek(60L, SeekOrigin.Begin) |> ignore
        use zs = new ZlibStream(fs, CompressionMode.Decompress)
        use sr = new StreamReader(zs)
        let s = sr.ReadToEnd()
        sr.Close()
        s
 
    let write fileName s =
        use fs = File.Open(fileName, FileMode.Create, FileAccess.ReadWrite)
        use zs = 
            new ZlibStream(
                fs, CompressionMode.Compress, 
                CompressionLevel.BestCompression, false )
        fs.WriteString(
            "PIAFILEVERSION_2.0,CTBVER1,compress\r\npmzlibcodec" +
            "\255\255\255\255\255\255\255\000\255\255\255\000" )
        zs.WriteString s
        zs.Close()

The read function will give you a string which is, to quote, "more or less 'human readable'".

[whoknows]

...
First, here's a short description of the PIA
...

About "here's" (http://www.noliturbare.com/more/faq#Q1):
is a good starting point, but contains several errors/lack of information
The header size is 60 No 59
bytes 49->52 = ZlibCodec.Adler32
bytes 53->56 = compressed stream size
bytes 57->60 = decompressed stream size

Look @ this:
http://www.theswamp.org/index.php?topic=37625.0