Category: <b>DOS kernel</b>
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<pre><b>INT 21 - DOS 2+ - GET RETURN CODE (ERRORLEVEL)</b>

	AH = 4Dh
Return: AH = termination type
	    00h normal (INT 20,INT 21/AH=00h, or INT 21/AH=4Ch)
	    01h control-C abort
	    02h critical error abort
	    03h terminate and stay resident (INT 21/AH=31h or INT 27)
	AL = return code
	CF clear
Notes:	the word in which DOS stores the return code is cleared after being
	  read by this function, so the return code can only be retrieved once
	COMMAND.COM stores the return code of the last external command it
	  executed as ERRORLEVEL
	this call should not be used if the child was started with AX=4B04h;
	  use AH=8Ah instead
	the following sequence will close a Virtual DOS Machine under OS/2 2.0
	  through OS/2 Merlin (but may change in the future):
	    MOV	AH,4Dh
	    INT	21h
	    HLT
	    DB	02h,0FDh
	  This sequence is the only way to close a specific VDM which was
	  booted from floppy or a disk image.
SeeAlso: AH=4Bh,AH=4Ch,AH=8Ah
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