(Go) Parse MIME Header Fields

Demonstrates how to parse MIME header fields, including Content-Type, Content-Disposition, and Content-Transfer-Encoding.

This example uses a MIME test file located at http://www.chilkatsoft.com/testData/sampleMime2.txt. It contains the following MIME:

Content-Type: multipart/mixed;
 boundary="------------080707010302060306060800";

This is a multi-part message in MIME format.

--------------080707010302060306060800
Content-Type: text/plain
Content-Transfer-Encoding: 7bit

This is the plain-text body.
--------------080707010302060306060800
Content-Disposition: attachment; filename="starfish.gif";
Content-Transfer-Encoding: base64
Content-Type: image/gif; name="starfish.gif";

R0lGODlhIAAgAPcAAP///+/v7/f39+/n5/fv7//39/fn597OzufW1tbGxs69vffe3u/W1salpZQQ
EIQYEJwQCJQYCJwYCM6clL2Ee5wpGIwhEK0YANatpdalnHMYCKUhCJQYAKUYAM6Ec5QhCJwhCPfW
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--------------080707010302060306060800--

Chilkat Go Downloads Go Package for Windows, MacOS, Linux, Alpine Linux, Solaris

    // This example requires the Chilkat API to have been previously unlocked.
    // See Global Unlock Sample for sample code.

    mime := chilkat.NewMime()

    // Load the sampleMime2.txt file into the MIME object.
    // (This file is available at http://www.chilkatsoft.com/testData/sampleMime2.txt )

    success := mime.LoadMimeFile("sampleMime2.txt")
    if success == false {
        fmt.Println(mime.LastErrorText())
        mime.DisposeMime()
        return
    }

    // The GIF image is the 2nd sub-part located directly under the
    // top-level MIME node.  Indexing begins at 0, therefore the 2nd
    // sub-part is at index 1.
    // part2 is a Mime
    part2 := mime.GetPart(1)

    // -------------------------------
    // Content-Disposition
    // -------------------------------
    // In this example, the Content-Disposition header field
    // contains this value:
    // attachment; filename="starfish.gif"

    // To get the "filename", call GetHeaderFieldAttribute
    // Header field names and attribute names are case insensitive.
    filename := part2.GetHeaderFieldAttribute("Content-Disposition","filename")
    fmt.Println("Filename: ", *filename)

    // Because the "filename" is so often accessed, it is also available
    // by accessing the "Filename" property:
    fmt.Println("Filename: ", part2.Filename())

    // The disposition (without attributes) which in this case 
    // is the string "attachment" is accessed via the Disposition property:
    fmt.Println("Disposition: ", part2.Disposition())

    // To get the full value of the Content-Disposition header field,
    // call GetHeaderField.
    fmt.Println("Content-Disposition: ", *part2.GetHeaderField("Content-Disposition"))

    // -------------------------------
    // Content-Type
    // -------------------------------
    // In this example, the Content-Type header field
    // contains this value:
    // image/gif; name="starfish.gif"

    // To get the "name", call GetHeaderFieldAttribute
    name := part2.GetHeaderFieldAttribute("Content-Type","name")
    fmt.Println("Content-Type name: ", *name)

    // Because the "name" is so often accessed, it is also available
    // by accessing the "Name" property:
    fmt.Println("Content-Type name: ", part2.Name())

    // The content-type without attributes is available in the
    // ContentType property:
    fmt.Println("Content-Type: ", part2.ContentType())

    // To get the full value of the Content-Type header field,
    // call GetHeaderField.
    fmt.Println("Content-Type: ", *part2.GetHeaderField("Content-Type"))

    // -------------------------------
    // Content-Transfer-Encoding
    // -------------------------------

    // The Encoding property contains the value of the
    // Content-Transfer-Encoding property. 
    // Calling GetHeaderField("Content-Transfer-Encoding") is
    // equivalent to accessing the Encoding property:
    fmt.Println("Content-Transfer-Encoding: ", part2.Encoding())
    fmt.Println("Content-Transfer-Encoding: ", *part2.GetHeaderField("Content-Transfer-Encoding"))

    part2.DisposeMime()

    fmt.Println("Finished.")

    mime.DisposeMime()