PRB: Query String Truncated (254786)

The information in this article applies to:

Microsoft Internet Explorer (Programming) 4.0
Microsoft Internet Explorer (Programming) 4.01
Microsoft Internet Explorer (Programming) 4.01 SP1
Microsoft Internet Explorer (Programming) 4.01 SP2
Microsoft Internet Explorer (Programming) 5
Microsoft Internet Explorer (Programming) 5.01
Microsoft Internet Explorer (Programming) 5.5
Microsoft Internet Explorer (Programming) 5_beta

This article was previously published under Q254786

SYMPTOMS

When you send a long query string from a WinInet application to a Web server, the query string may be truncated.

CAUSE

This issue occurs because of the length limitation of the URL in WinInet, which is defined in the Wininet.h file as follows:

#define INTERNET_MAX_PATH_LENGTH        2048
#define INTERNET_MAX_SCHEME_LENGTH      32          // longest protocol name length
#define INTERNET_MAX_URL_LENGTH         (INTERNET_MAX_SCHEME_LENGTH + sizeof("://") + INTERNET_MAX_PATH_LENGTH)

This behavior is by design.

Note: Because Internet Explorer and Internet Transfer Control also use WinInet, the same issue may occur.

RESOLUTION

To resolve this issue, use the HTTP POST method. For example:

Using Internet Transfer Control on the client side:

Private Sub Command1_Click()
Dim strData As String
strData = "QName=longquerystring+longquerystring+longquerystring+longquerystring"
Inet1.Execute "http://myserver/scripts/post.asp", "POST", strData, "Content-Type: application/x-www-form-urlencoded" & vbCrLf & "Connection: Keep-Alive"
End Sub

Using ASP on the server side:

<HTML>
<% cName = Request("QName") %>
<BODY>
Hello, the data you posted is: <br>
<% =CName %>. 
</BODY>
</HTML>

<HTML>
<BODY>
Hello, the data you posted is: <br>
<%
Response.Write(Request.Form("QName"))
%>.
</BODY>
</HTML>

MORE INFORMATION

Microsoft provides programming examples for illustration only, without warranty either expressed or implied. This includes, but is not limited to, the implied warranties of merchantability or fitness for a particular purpose. This article assumes that you are familiar with the programming language that is being demonstrated and with the tools that are used to create and to debug procedures. Microsoft support engineers can help explain the functionality of a particular procedure, but they will not modify these examples to provide added functionality or construct procedures to meet your specific requirements.
For additional information on how to properly simulate a Form POST in WinInet, click the article number below to view the article in the Microsoft Knowledge Base:

165298 HOWTO: Simulate a Form POST Request Using WinInet

REFERENCES

For more information on URL-encoding and the format of a Form POST request, see section 8.2 in RFC 1866.

Modification Type:	Major	Last Reviewed:	6/24/2005
Keywords:	kbprb KB254786