cgi32.bas

用VB做的CGI程序 用VB做的CGI程序

Attribute VB_Name = "cgi32"
'***************EBIZ.EXE*****************************
'THIS MODULE WAS NOT CREATED BY AUTHOR OF EBIZ.EXE
'*****************************************************
'----------------------------------------------------------------------
'       *************
'       * CGI32.BAS *
'       *************
'
' VERSION: 1.9  (July 17, 1997)
'
' AUTHORS: Robert B. Denny <[e-mail]>
'          Christopher J. Duke <[e-mail]>
'
' Common routines needed to establish a VB environment for
' Windows CGI programs that run behind the WebSite Server.
'
' INTRODUCTION
'
' The Common Gateway Interface (CGI) version 1.1 specifies a minimal
' set of data that is made available to the back-end application by
' an HTTP (Web) server. It also specifies the details for passing this
' information to the back-end. The latter part of the CGI spec is
' specific to Unix-like environments. The NCSA httpd for Windows does
' supply the data items (and more) specified by CGI/1.1, however it
' uses a different method for passing the data to the back-end.
'
' DEVELOPMENT
'
' WebSite requires any Windows back-end program to be an
' executable image. This means that you must convert your VB
' application into an executable (.EXE) before it can be tested
' with the server.
'
' ENVIRONMENT
'
' The WebSite server executes script requests by doing a
' CreateProcess with a command line in the following form:
'
'   prog-name cgi-profile
'
' THE CGI PROFILE FILE
'
' The Unix CGI passes data to the back end by defining environment
' variables which can be used by shell scripts. The WebSite
' server passes data to its back end via the profile file. The
' format of the profile is that of a Windows ".INI" file. The keyword
' names have been changed cosmetically.
'
' There are 7 sections in a CGI profile file, [CGI], [Accept],
' [System], [Extra Headers], and [Form Literal], [Form External],
' and [Form huge]. They are described below:
'
' [CGI]                <== The standard CGI variables
' CGI Version=         The version of CGI spoken by the server
' Request Protocol=    The server's info protocol (e.g. HTTP/1.0)
' Request Method=      The method specified in the request (e.g., "GET")
' Request Keep-Alive=  If the client requested connection re-use (Yes/No)
' Executable Path=     Physical pathname of the back-end (this program)
' Logical Path=        Extra path info in logical space
' Physical Path=       Extra path info in local physical space
' Query String=        String following the "?" in the request URL
' Content Type=        MIME content type of info supplied with request
' Content Length=      Length, bytes, of info supplied with request
' Request Range=       Byte-range specfication received with request
' Server Software=     Version/revision of the info (HTTP) server
' Server Name=         Server's network hostname (or alias from config)
' Server Port=         Server's network port number
' Server Admin=        E-Mail address of server's admin. (config)
' Referer=             URL of referring document
' From=                E-Mail of client user (rarely seen)
' User Agent=          String describing client/browser software/version
' Remote Host=         Remote client's network hostname
' Remote Address=      Remote client's network address
' Authenticated Username=Username if present in request
' Authenticated Password=Password if present in request
' Authentication Method=Method used for authentication (e.g., "Basic")
' Authentication Realm=Name of realm for users/groups
'
' [Accept]             <== What the client says it can take
' The MIME types found in the request header as
'    Accept: xxx/yyy; zzzz...
' are entered in this section as
'    xxx/yyy=zzzz...
' If only the MIME type appears, the form is
'    xxx/yyy=Yes
'
' [System]             <== Windows interface specifics
' GMT Offset=          Offset of local timezone from GMT, seconds (LONG!)
' Output File=         Pathname of file to receive results
' Content File=        Pathname of file containing raw request content
' Debug Mode=          If server's CGI debug flag is set (Yes/No)
'
' [Extra Headers]
' Any "extra" headers found in the request that activated this
' program. They are listed in "key=value" form. Usually, you'll see
' at least the name of the browser here as "User-agent".
'
' [Form Literal]
' If the request was a POST from a Mosaic form (with content type of
' "application/x-www-form-urlencoded"), the server will decode the
' form data. Raw form input is of the form "key=value&key=value&...",
' with the value parts "URL-encoded". The server splits the key=value
' pairs at the '&', then spilts the key and value at the '=',
' URL-decodes the value string and puts the result into key=value
' (decoded) form in the [Form Literal] section of the INI.
'
' [Form External]
' If the decoded value string is more than 254 characters long,
' or if the decoded value string contains any control characters
' or quote marks the server puts the decoded value into an external
' tempfile and lists the field in this section as:
'    key=<pathname> <length>
' where <pathname> is the path and name of the tempfile containing
' the decoded value string, and <length> is the length in bytes
' of the decoded value string.
'
' NOTE: BE SURE TO OPEN THIS FILE IN BINARY MODE UNLESS YOU ARE
'       CERTAIN THAT THE FORM DATA IS TEXT!
'
' [Form File]
' If the form data contained any uploaded files, they are described in
' this section as:
'    key=[<pathname>] <length> <type> <encoding> [<name>]
' where <pathname> is the path and name of the tempfile contining the
' uploaded file, <length> is the length in bytes of the uploaded file,
' <type> is the content type of the uploaded file as sent by the browser,
' <encoding> is the content-transfer encoding of the uploaded file, and
' <name> is the original file name of the uploaded file.
'
' [Form Huge]
' If the raw value string is more than 65,536 bytes long, the server
' does no decoding. In this case, the server lists the field in this
' section as:
'    key=<offset> <length>
' where <offset> is the offset from the beginning of the Content File
' at which the raw value string for this key is located, and <length>
' is the length in bytes of the raw value string. You can use the
' <offset> to perform a "Seek" to the start of the raw value string,
' and use the length to know when you have read the entire raw string
' into your decoder. Note that VB has a limit of 64K for strings, so
'
' Examples:
'
'    [Form Literal]
'    smallfield=123 Main St. #122
'
'    [Form External]
'    field300chars=c:\website\cgi-tmp\1a7fws.000 300
'    fieldwithlinebreaks=c:\website\cgi-tmp\1a7fws.001 43
'
'    [Form Huge]
'    field230K=c:\website\cgi-tmp\1a7fws.002 276920
'
' =====
' USAGE
' =====
' Include CGI32.BAS in your VB4 or VB5 project. Set the project options for
' "Sub Main" startup. The Main() procedure is in this module, and it
' handles all of the setup of the VB CGI environment, as described
' above. Once all of this is done, the Main() calls YOUR main procedure
' which must be called CGI_Main(). The output file is open, use Send()
' to write to it. The input file is NOT open, and "huge" form fields
' have not been decoded.
'
' NOTE: If your program is started without command-line args,
' the code assumes you want to run it interactively. This is useful
' for providing a setup screen, etc. Instead of calling CGI_Main(),
' it calls Inter_Main(). Your module must also implement this
' function. If you don't need an interactive mode, just create
' Inter_Main() and put a 1-line call to MsgBox alerting the
' user that the program is not meant to be run interactively.
' The samples furnished with the server do this.
'
' If a Visual Basic runtime error occurs, it will be trapped and result
' in an HTTP error response being sent to the client. Check out the
' Error Handler() sub. When your program finishes, be sure to RETURN
' TO MAIN(). Don't just do an "End".
'
' Have a look at the stuff below to see what's what.
'
'----------------------------------------------------------------------
' Author:   Robert B. Denny <[e-mail]>
'           April 15, 1995
'
' Revision History:
'   15-Apr-95 rbd   Initial release (ref VB3 CGI.BAS 1.7)
'   02-Aug-95 rbd   Changed to take input and output files from profile
'                   Server no longer produces long command line.
'   24-Aug-95 rbd   Make call to GetPrivateProfileString conditional
'                   so 16-bit and 32-bit versions supported. Fix
'                   computation of CGI_GMTOffset for offset=0 (GMT)
'                   case. Add FieldPresent() routine for checkbox
'                   handling. Clean up comments.
'   29-Oct-95 rbd   Added PlusToSpace() and Unescape() functions for
'                   decoding query strings, etc.
'   16-Nov-95 rbd   Add keep-alive variable, file uploading description
'                   in comments, and upload display.
'   20-Nov-95 rbd   Fencepost error in ParseFileValue()
'   23-Nov-95 rbd   Remove On Error Resume Next from error handler
'   03-Dec-95 rbd   User-Agent is now a variable, real HTTP header
'                   Add Request-Range as http header as well.
'   30-Dec-96 rbd   Fix "endless" loop if call FieldPresent() with
'                   zero form fields.
'   23-Feb-97 rbd   Per MS Tech Support, do not do Exit Sub in sub Main
'                   as this can corrupt VB40032.DLL. Use End instead.
'   17-Jul-97 cjd   1.9: Removed MAX_FORM_TUPLES (was previously a
'                   constant set to 100) and replaced it with a
'                   varying-sized array in GetFormTuples().
'----------------------------------------------------------------------
Option Explicit
'
' ==================
' Manifest Constants
' ==================
'
Const MAX_CMDARGS = 8       ' Max # of command line args
Const ENUM_BUF_SIZE = 4096  ' Key enumeration buffer, see GetProfile()
' These are the limits in the server
Const MAX_XHDR = 100        ' Max # of "extra" request headers
Const MAX_ACCTYPE = 100     ' Max # of Accept: types in request
Const MAX_HUGE_TUPLES = 16  ' Max # "huge" form fields
Const MAX_FILE_TUPLES = 16  ' Max # of uploaded file tuples
'
'
' =====
' Types
' =====
'
Type Tuple                  ' Used for Accept: and "extra" headers
    key As String           ' and for holding POST form key=value pairs
    value As String
End Type

Type FileTuple              ' Used for form-based file uploads
    key As String           ' Form field name
    file As String          ' Local tempfile containing uploaded file
    length As Long          ' Length in bytes of uploaded file
    type As String          ' Content type of uploaded file
    encoding As String      ' Content-transfer encoding of uploaded file
    name As String          ' Original name of uploaded file
End Type

Type HugeTuple              ' Used for "huge" form fields
    key As String           ' Keyword (decoded)
    offset As Long          ' Byte offset into Content File of value
    length As Long          ' Length of value, bytes
End Type
'
'
' ================
' Global Constants
' ================
'
' -----------
' Error Codes
' -----------
'
Global Const ERR_ARGCOUNT = 32767
Global Const ERR_BAD_REQUEST = 32766        ' HTTP 400
Global Const ERR_UNAUTHORIZED = 32765       ' HTTP 401
Global Const ERR_PAYMENT_REQUIRED = 32764   ' HTTP 402
Global Const ERR_FORBIDDEN = 32763          ' HTTP 403
Global Const ERR_NOT_FOUND = 32762          ' HTTP 404
Global Const ERR_INTERNAL_ERROR = 32761     ' HTTP 500
Global Const ERR_NOT_IMPLEMENTED = 32760    ' HTTP 501
Global Const ERR_TOO_BUSY = 32758           ' HTTP 503 (experimental)
Global Const ERR_NO_FIELD = 32757           ' GetxxxField "no field"
Global Const CGI_ERR_START = 32757          ' Start of our errors

' ====================
' CGI Global Variables
' ====================
'
' ----------------------
' Standard CGI variables
' ----------------------
'
Global CGI_ServerSoftware As String
Global CGI_ServerName As String
Global CGI_ServerPort As Integer
Global CGI_RequestProtocol As String
Global CGI_ServerAdmin As String
Global CGI_Version As String
Global CGI_RequestMethod As String
Global CGI_RequestKeepAlive As Integer
Global CGI_LogicalPath As String
Global CGI_PhysicalPath As String
Global CGI_ExecutablePath As String
Global CGI_QueryString As String
Global CGI_RequestRange As String
Global CGI_Referer As String
Global CGI_From As String
Global CGI_UserAgent As String
Global CGI_RemoteHost As String
Global CGI_RemoteAddr As String
Global CGI_AuthUser As String
Global CGI_AuthPass As String
Global CGI_AuthType As String
Global CGI_AuthRealm As String
Global CGI_ContentType As String
Global CGI_ContentLength As Long
'
' ------------------
' HTTP Header Arrays
' ------------------
'
Global CGI_AcceptTypes(MAX_ACCTYPE) As Tuple    ' Accept: types
Global CGI_NumAcceptTypes As Integer            ' # of live entries in array
Global CGI_ExtraHeaders(MAX_XHDR) As Tuple      ' "Extra" headers
Global CGI_NumExtraHeaders As Integer           ' # of live entries in array
'
' --------------
' POST Form Data
' --------------
'
Global CGI_FormTuples() As Tuple                ' Declare dynamic array for POST form key=value pairs