How can I eject a CD via the cmd?

You can eject a cd with a batch file (this is part vbscript

@echo off
echo Set oWMP = CreateObject("WMPlayer.OCX.7")  >> %temp%\temp.vbs
echo Set colCDROMs = oWMP.cdromCollection       >> %temp%\temp.vbs
echo For i = 0 to colCDROMs.Count-1             >> %temp%\temp.vbs
echo colCDROMs.Item(i).Eject                    >> %temp%\temp.vbs
echo next                                       >> %temp%\temp.vbs
echo oWMP.close                                 >> %temp%\temp.vbs
%temp%\temp.vbs
timeout /t 1
del %temp%\temp.vbs

This is not my work, I found it in the stackoverflow community:

Post Link: Batch Command Line to Eject CD Tray?
Answer Author: Bruno
Date Answered: Feb 10, 2015

You could use the Shell.Application COM object's InvokeVerb method. From a cmd prompt, you can abuse a PowerShell one-liner thusly:

powershell "(new-object -COM Shell.Application).NameSpace(17).ParseName('D:').InvokeVerb('Eject')"

You can also use Windows Scripting Host (VBScript / JScript) to invoke the COM object. Here's an example using a hybrid Batch + Jscript script (save it with a .bat extension):

@if (@CodeSection == @Batch) @then

@echo off
setlocal

set "CDdrive=D:"

cscript /nologo /e:JScript "%~f0" "%CDdrive%"

goto :EOF

@end // end batch / begin JScript hybrid chimera
var oSH = WSH.CreateObject('Shell.Application');
oSH.NameSpace(17).ParseName(WSH.Arguments(0)).InvokeVerb('Eject');

If you prefer to have your script detect the drive letter for the CD drive, that can be arranged as well. Here's a more complete version with comments explaining some of the non-self-explanatory values.

@if (@CodeSection == @Batch) @then

@echo off
setlocal

cscript /nologo /e:JScript "%~f0"

goto :EOF

@end // end batch / begin JScript hybrid chimera

// DriveType=4 means CD drive for a WScript FSO object.
// See http://msdn.microsoft.com/en-us/library/ys4ctaz0%28v=vs.84%29.aspx

// NameSpace(17) = ssfDRIVES, or My Computer.
// See http://msdn.microsoft.com/en-us/library/windows/desktop/bb774096%28v=vs.85%29.aspx

var oSH = new ActiveXObject('Shell.Application'),
    FSO = new ActiveXObject('Scripting.FileSystemObject'),
    CDdriveType = 4,
    ssfDRIVES = 17,
    drives = new Enumerator(FSO.Drives);

while (!drives.atEnd()) {
    var x = drives.item();
    if (x.DriveType == CDdriveType) {
        oSH.NameSpace(ssfDRIVES).ParseName(x.DriveLetter + ':').InvokeVerb('Eject');
        while (x.IsReady)
            WSH.Sleep(50);
    }
    drives.moveNext();
}

Using WMPlayer.OCX.7 will startled most of the anti-virus programs and there are some versions of windows that come without media player. Here's a way with shell.application and invokeVerb function:

save this with .bat extension:

@cScript.EXE //noLogo "%~f0?.WSF"  //job:info %~nx0 %*
@exit /b 0

   <job id="info">
      <script language="VBScript">
        if WScript.Arguments.Count < 2 then
            WScript.Echo "No drive letter passed"
            WScript.Echo "Usage: " 
            WScript.Echo "  " & WScript.Arguments.Item(0) & " {LETTER|*}"
            WScript.Echo "  * will eject all cd drives"
            WScript.Quit 1
        end if
        driveletter = WScript.Arguments.Item(1):
        driveletter = mid(driveletter,1,1):

        Public Function ejectDrive (drvLtr)
            Set objApp = CreateObject( "Shell.Application" ):
            Set objF=objApp.NameSpace(&H11&):
            'WScript.Echo(objF.Items().Count):
            set MyComp = objF.Items():
            for each item in objF.Items() :
                iName = objF.GetDetailsOf (item,0): 
                iType = objF.GetDetailsOf (item,1): 
                iLabels = split (iName , "(" ) :
                iLabel = iLabels(1):

                if Ucase(drvLtr & ":)") = iLabel and iType = "CD Drive" then
                    set verbs=item.Verbs():
                    set verb=verbs.Item(verbs.Count-4):
                    verb.DoIt():
                    item.InvokeVerb replace(verb,"&","") :
                    ejectDrive = 1:
                    exit function:

                end if
            next    
            ejectDrive = 2:
        End Function

        Public Function ejectAll ()
            Set objApp = CreateObject( "Shell.Application" ):

            Set objF=objApp.NameSpace(&H11&):
            'WScript.Echo(objF.Items().Count):
            set MyComp = objF.Items():
            for each item in objF.Items() :
                iType = objF.GetDetailsOf (item,1):                                 
                if  iType = "CD Drive" then
                    set verbs=item.Verbs():
                    set verb=verbs.Item(verbs.Count-4):
                    verb.DoIt():
                    item.InvokeVerb replace(verb,"&","") :
                end if

            next
        End Function
        if driveletter = "*" then 
            call ejectAll
            WScript.Quit 0
        end if
        result = ejectDrive (driveletter):

        if result = 2 then
            WScript.Echo "no cd drive found with letter " & driveletter & ":"
            WScript.Quit 2
        end if

      </script>
  </job>

You can use it like (for more info -)

call eject.bat *