Modem Enumeration in Win2k?

[Michael Burns]

In Windows 95/98/Me, one can enumerate the modems on a machine,
and what ports they are attached to, by examining the entries
under HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Class\Modem\

For example, code like this generally works pretty well (search the forum
to locate the GetStringValue sub).

FUNCTION EnumerateModemWindowsInit (ComPortToMatch AS INTEGER, ModemInitString AS STRING,_
             ModemCommandPrefix AS STRING, ModemHangUp AS STRING, ModemDialPrefix AS STRING, _
             ModemDialSuffix AS STRING, ModemSpeakerOff AS STRING, ModemNum AS INTEGER) AS STRING
   '
   '   Here we examine the Modem Registry Settings
   '   Find out which one is on ComPortToMatch
   '   and we get the Windows command strings for dialing, hanging up,
   '   turning off the speaker, and putting things back to the Windows
   '   defaults. Note that by getting the command & dial prefixes, and dial
   '   suffix, we are not restricted to Hayes compatible modems.
   '
   '    EnumerateModemWindowsInit itself is a string of the description of the modem
   '

    LOCAL I AS INTEGER
    LOCAL A$
    LOCAL KEY$
    ModemInitString=""
    KEY$="HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Class\Modem\"
    ModemNum=0
CheckModem:
    A$ = GetStringValue(KEY$+TRIM$(FORMAT$(ModemNum,"0000")), "DriverDesc")
    IF A$="" AND ModemNum>8 THEN
            FUNCTION = ""
            ModemInitString=""
            ModemCommandPrefix=""
            ModemHangUp=""
            ModemDialPrefix=""
            ModemDialSuffix=""
            ModemSpeakerOff=""
       EXIT FUNCTION
    END IF
    IF A$<>"" THEN
        FUNCTION = A$
        A$ = GetStringValue(KEY$+TRIM$(FORMAT$(ModemNum,"0000")), "AttachedTo")
        A$=TRIM$(A$)
        A$=RIGHT$(A$,1)
        I=VAL(A$)
        IF I = ComPortToMatch THEN
           ModemInitString = GetStringValue(KEY$+TRIM$(FORMAT$(ModemNum,"0000"))+"\Init", "2")
           ModemInitString = REMOVE$(ModemInitString, "<cr>")
           ModemCommandPrefix = GetStringValue(KEY$+TRIM$(FORMAT$(ModemNum,"0000"))+"\Init", "1")
           ModemCommandPrefix = REMOVE$(ModemCommandPrefix, "<cr>")
           ModemHangUp = GetStringValue(KEY$+TRIM$(FORMAT$(ModemNum,"0000"))+"\Hangup", "1")
           ModemHangUp = REMOVE$(ModemHangUp, "<cr>")
           ModemDialPrefix = GetStringValue(KEY$+TRIM$(FORMAT$(ModemNum,"0000"))+"\Settings", "DialPrefix")
           ModemDialSuffix = GetStringValue(KEY$+TRIM$(FORMAT$(ModemNum,"0000"))+"\Settings", "DialSuffix")
           ModemSpeakerOff  = GetStringValue(KEY$+TRIM$(FORMAT$(ModemNum,"0000"))+"\Settings", "SpeakerMode_Off")
           EXIT FUNCTION
        END IF
    END IF
    ModemNum=ModemNum+1
    GOTO CheckModem
END FUNCTION

However, in Windows 2000 the modem info is stored elsewhere, as near
as I can tell not in the System Registry at all. Does not appear (to
me) to be available in the RAS routines either. Does anyone know
how to find, in Windows 2000, what modem is assigned to what COM
port?

------------------
Michael Burns

[Michael Burns]

Well, here is a modification to the code above that works, although (in Win 2k)
it assumes the modem is Hayes comatible. Again, search for the GetStringValue
routine. I've added the GetOSVersion the modem enumeration routine now requires.

FUNCTION GetOSVersion AS STRING
   '
   '    This gets what version of Windows you are running and returns it as a string
   '
   LOCAL OSVer AS OSVERSIONINFO
   LOCAL lResult  AS LONG
   OSVer.dwOSVersionInfoSize = SIZEOF(OSVer)
   lResult = GetVersionEx(OSVer)
   lResult= LOWRD(OSVer.dwBuildNumber)
   IF lResult = 950 THEN
      FUNCTION="Windows 95"
      EXIT FUNCTION
   END IF
   IF lResult = 1111 THEN
      FUNCTION="Windows 95 OSR2"
      EXIT FUNCTION
   END IF
   IF lResult = 1998 THEN
      FUNCTION="Windows 98"
      EXIT FUNCTION
   END IF
   IF lResult = 2222 THEN
      FUNCTION="Windows 98 SE"
      EXIT FUNCTION
   END IF
   IF lResult = 3000 THEN
      FUNCTION="Windows ME"
      EXIT FUNCTION
   END IF
   IF lResult = 1381 THEN
      FUNCTION="Windows NT v4"
      EXIT FUNCTION
   END IF
   IF lResult = 2195 THEN
      FUNCTION="Windows 2000"
      EXIT FUNCTION
   END IF
   FUNCTION="Windows version unknown"
END FUNCTION   
'********************************************
FUNCTION EnumerateModemWindowsInit (ComPortToMatch AS INTEGER, ModemInitString AS STRING,_
             ModemCommandPrefix AS STRING, ModemHangUp AS STRING, ModemDialPrefix AS STRING, _
             ModemDialSuffix AS STRING, ModemSpeakerOff AS STRING, ModemNum AS INTEGER) AS STRING
   '
   '   Win 95/98/Me: Here we examine the Modem Registry Settings
   '   Find out which one is on ComPortToMatch
   '   and we get the Windows command strings for dialing, hanging up,
   '   turning off the speaker, and putting things back to the Windows
   '   defaults. Note that by getting the command & dial prefixes, and dial
   '   suffix, we are not restricted to Hayes compatible modems.
   '
   '   Win 2k/Nt: We are restricted (at present) to Hayes compatible modems.
   '
   '    EnumerateModemWindowsInit itself is a string of the description of the modem
   '
    'LOCAL ModemNum AS INTEGER
    LOCAL I AS INTEGER
    LOCAL A$
    LOCAL KEY$
    ModemInitString=""
    IF GetOSVersion<>"Windows 2000" AND GetOSVersion<>"Windows NT v4" THEN
        '
        '   Deal with situation for Win 95/98/Me
        '
        KEY$="HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Class\Modem\"
        ModemNum=0
CheckModem:
        A$ = GetStringValue(KEY$+TRIM$(FORMAT$(ModemNum,"0000")), "DriverDesc")
        IF A$="" AND ModemNum>8 THEN
            FUNCTION = ""
            ModemInitString=""
            ModemCommandPrefix=""
            ModemHangUp=""
            ModemDialPrefix=""
            ModemDialSuffix=""
            ModemSpeakerOff=""
            EXIT FUNCTION
        END IF
        IF A$<>"" THEN
            FUNCTION = A$
            A$ = GetStringValue(KEY$+TRIM$(FORMAT$(ModemNum,"0000")), "AttachedTo")
            A$=TRIM$(A$)
            A$=RIGHT$(A$,1)
            I=VAL(A$)
            IF I = ComPortToMatch THEN
                ModemInitString = GetStringValue(KEY$+TRIM$(FORMAT$(ModemNum,"0000"))+"\Init", "2")
                ModemInitString = REMOVE$(ModemInitString, "<cr>")
                ModemCommandPrefix = GetStringValue(KEY$+TRIM$(FORMAT$(ModemNum,"0000"))+"\Init", "1")
                ModemCommandPrefix = REMOVE$(ModemCommandPrefix, "<cr>")
                ModemHangUp = GetStringValue(KEY$+TRIM$(FORMAT$(ModemNum,"0000"))+"\Hangup", "1")
                ModemHangUp = REMOVE$(ModemHangUp, "<cr>")
                ModemDialPrefix = GetStringValue(KEY$+TRIM$(FORMAT$(ModemNum,"0000"))+"\Settings", "DialPrefix")
                ModemDialSuffix = GetStringValue(KEY$+TRIM$(FORMAT$(ModemNum,"0000"))+"\Settings", "DialSuffix")
                ModemSpeakerOff  = GetStringValue(KEY$+TRIM$(FORMAT$(ModemNum,"0000"))+"\Settings", "SpeakerMode_Off")
                EXIT FUNCTION
            END IF
        END IF
        ModemNum=ModemNum+1
        GOTO CheckModem
    ELSE
        '
        '   Deal with situation for Win 2k/NT
        '   We assume the modem is Hayes compatible.
        '
        A$ = GetStringValue("HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Ras\Tapi Devices\Unimodem", "Friendly Name")
        IF A$<>"" THEN
           FUNCTION = A$
           A$ = GetStringValue("HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Ras\Tapi Devices\Unimodem", "Address")
           A$=TRIM$(A$)
           A$=RIGHT$(A$,1)
           I=VAL(A$)
           A$ = GetStringValue("HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Ras\Tapi Devices\Unimodem", "Media Type")
           IF I = ComPortToMatch AND A$="Modem" THEN
              ModemInitString = "ATE0Q0&C1&D2V1"
              ModemCommandPrefix = "AT"
              ModemHangUp = "ATH"
              ModemDialPrefix = "D"
              ModemDialSuffix = ";"
              ModemSpeakerOff  = "M"
              EXIT FUNCTION
           ELSE
              FUNCTION = ""
              ModemInitString=""
              ModemCommandPrefix=""
              ModemHangUp=""
              ModemDialPrefix=""
              ModemDialSuffix=""
              ModemSpeakerOff=""
              EXIT FUNCTION
           END IF
        END IF
    END IF
END FUNCTION

------------------
Michael Burns

[Lance Edmonds]

I can't find the GetStringValue() function on the BBS, just a few references to the name.

Could you please post that function too, Michael? Thanks!


------------------
Lance
PowerBASIC Support
mailto:[email protected][email protected]</A>

[Sven Blumenstein]

getStringValue
public String getStringValue(String name,String defval);


Queries a string value from the registry. The name is a subkey of the current key. If the named value does not exist in the registry, the specified default value is returned. 

Return Value: 

Returns the default value if the named value does not exist in the registry. Otherwise, the method returns the string value contained in the subkey. 

Parameter Description 
name  The subkey containing the requested string.  
defval  The default value to return.

------------------
Sven Blumenstein
IT-Trainee at DECOMA Exterior Systems, Germany
E-Mail (work): mailto:[email protected][email protected]</A>
E-Mail (home): mailto:[email protected][email protected]</A>
Favorite Languages: PB/Dll, MASM, VB, VC++, LCC, VBA, WML

[Michael Burns]

Originally posted by Lance Edmonds:
I can't find the GetStringValue() function on the BBS, just a few references to the name.

Could you please post that function too, Michael? Thanks!

For some reason I thought it was posted already. Here it is, along
with the routines it calls:

GLOBAL True AS INTEGER
GLOBAL False AS INTEGER
GLOBAL rtn AS LONG 

FUNCTION GetMainKeyHandle(MainKeyName AS STRING) AS LONG

SELECT CASE MainKeyName
       CASE "HKEY_CLASSES_ROOT"
            GetMainKeyHandle = %HKEY_CLASSES_ROOT
       CASE "HKEY_CURRENT_USER"
            GetMainKeyHandle = %HKEY_CURRENT_USER
       CASE "HKEY_LOCAL_MACHINE"
            GetMainKeyHandle = %HKEY_LOCAL_MACHINE
       CASE "HKEY_USERS"
            GetMainKeyHandle = %HKEY_USERS
       CASE "HKEY_PERFORMANCE_DATA"
            GetMainKeyHandle = %HKEY_PERFORMANCE_DATA
       CASE "HKEY_CURRENT_CONFIG"
            GetMainKeyHandle = %HKEY_CURRENT_CONFIG
       CASE "HKEY_DYN_DATA"
            GetMainKeyHandle = %HKEY_DYN_DATA
END SELECT

END FUNCTION

'********************************************************
SUB ParseKey(Keyname AS STRING, Keyhandle AS LONG)

rtn = INSTR(Keyname, "\") 'return if "\" is contained in the Keyname

IF LEFT$(Keyname, 5) <> "HKEY_" OR RIGHT$(Keyname, 1) = "\" THEN 'if there is a "\" at the end of the Keyname then
   MSGBOX "Incorrect Format:" + CHR$(10) + CHR$(10) + Keyname,, "ParseKey" 'display error to the user
   EXIT SUB 'exit the procedure
ELSEIF rtn = 0 THEN 'if the Keyname contains no "\"
   Keyhandle = GetMainKeyHandle(Keyname)
   Keyname = "" 'leave Keyname blank
ELSE 'otherwise, Keyname contains "\"
   Keyhandle = GetMainKeyHandle(LEFT$(Keyname, rtn - 1)) 'seperate the Keyname
   Keyname = RIGHT$(Keyname, LEN(Keyname) - rtn)
END IF

END SUB

'********************************************************
FUNCTION GetStringValue(SubKey AS STRING, Entry AS STRING) AS STRING

DIM rtn AS LONG
DIM SubKeyz AS ASCIIZ * 256
DIM sBufferz AS ASCIIZ * 256
DIM Entryz AS ASCIIZ * 256

CALL ParseKey(SubKey, MainKeyHandle)
SubKeyz=SubKey + CHR$(0)
Entryz=Entry + CHR$(0)
IF MainKeyHandle THEN
   rtn = RegOpenKeyEx(MainKeyHandle, SubKeyz, 0, %KEY_READ, hKey) 'open the key
   IF rtn = %ERROR_SUCCESS THEN 'if the key could be opened then
      lBufferSize = 256
      rtn = RegQueryValueEx(hKey, Entryz, 0, %REG_SZ, sBufferz, 255) 'get the value from the registry
      IF rtn = %ERROR_SUCCESS THEN 'if the value could be retreived then
         rtn = RegCloseKey(hKey)  'close the key
         sBufferz = TRIM$(sBufferz)
         GetStringValue = sBufferz 'return the value to the user
      ELSE                        'otherwise, if the value couldnt be retreived
         GetStringValue = ""             ' return null string to user
      END IF
   ELSE 'otherwise, if the key couldnt be opened
      GetStringValue = ""             ' return null string to user
   END IF
END IF
END FUNCTION
'********************************************************

------------------
Michael Burns



[This message has been edited by Michael Burns (edited September 10, 2001).]

[Michael Burns]

I should point out that the Win 95/98/Me modem enumeration
routine above does require that the modem have its "AttachedTo"
registry entry properly filled out. I have noticed that not all
modems have this entry. I do have a routine, that is rather
convoluted (and not very readable) that when called looks at all
the modems it can find in
HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Class\Modem\
and checks for an AttachedTo entry. If there is none, then it looks
for an MatchingDeviceID Key.

If an MatchingDeviceID Key is found, it uses that to look in the
HKEY_LOCAL_MACHINE\Enum\PCI\ area and its subkeys looking for a
PORTNAME Key. If it finds a PORTNAME Key, it then goes back and
patches the missing "AttachedTo" entry. If people are interested,
I'll post it.

------------------
Michael Burns

[This message has been edited by Michael Burns (edited September 10, 2001).]

[Neil Hosgood]

Michael,

Do a search for CreateRAS in the forums and you should find
Daves code which includes a call to RASEmunDevices. It works
for me on win2K.

Have Fun.
NJH.

------------------