' ReadDXF extracts specified code/value pairs from a DXF file.

' This function requires four string parameters, a valid DXF

' file name, a DXF section name, the name of an object in that

' section, and a comma delimited list of codes.

'

Function ReadDXF( _

		ByVal dxfFile As String, ByVal strSection As String, _

		ByVal strObject As String, ByVal strCodeList As String)

	Dim tmpCode, lastObj As String

	Open dxfFile For Input As #1

	' Get the first code/value pair

	codes = ReadCodes

	' Loop through the whole file until the "EOF" line

	While codes(1) <> "EOF"

		' If the group code is '0' and the value is 'SECTION' ..

		If codes(0) = "0" And codes(1) = "SECTION" Then

			' This must be a new section, so get the next

			' code/value pair.

			codes = ReadCodes()

			' If this section is the right one ..

			If codes(1) = strSection Then

				' Get the next code/value pair and ..

				codes = ReadCodes

				' Loop through this section until the 'ENDSEC'

				While codes(1) <> "ENDSEC"

					' While in a section, all '0' codes indicate

					' an object. If you find a '0' store the

					' object name for future use.

					If codes(0) = "0" Then lastObj = codes(1)

					' If this object is one you're interested in

					If lastObj = strObject Then

						' Surround the code with commas

						tmpCode = "," & codes(0) & ","

						' If this code is in the list of codes ..

						If InStr(strCodeList, tmpCode) Then

							' Append the return value.

							ReadDXF = ReadDXF & _

								codes(0) & "=" & codes(1) & vbCrLf

						End If

					End If

					' Read another code/value pair

					codes = ReadCodes

				Wend

			End If

		Else

			codes = ReadCodes

		End If

	Wend

	Close #1

End Function

' ReadCodes reads two lines from an open file and returns a two item

' array, a group code and its value. As long as a DXF file is read 

' two lines at a time, all should be fine. However, to make your 

' code more reliable, you should add some additional error and

' other checking.

'

Function ReadCodes() As Variant

	Dim codeStr, valStr As String

	Line Input #1, codeStr

	Line Input #1, valStr

	' Trim the leading and trailing space from the code

	ReadCodes = Array(Trim(codeStr), valStr)

End Function