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213F

Category: DOS kernel

INT 21 - DOS 2+ - "READ" - READ FROM FILE OR DEVICE

	AH = 3Fh
	BX = file handle
	CX = number of bytes to read
	DS:DX -> buffer for data
Return: CF clear if successful
	    AX = number of bytes actually read (0 if at EOF before call)
	CF set on error
	    AX = error code (05h,06h) (see #01680 at AH=59h/BX=0000h)
Notes:	data is read beginning at current file position, and the file position
	  is updated after a successful read
	the returned AX may be smaller than the request in CX if a partial
	  read occurred
	if reading from CON, read stops at first CR
	under the FlashTek X-32 DOS extender, the pointer is in DS:EDX
BUG:	Novell NETX.EXE v3.26 and 3.31 do not set CF if the read fails due to
	  a record lock (see AH=5Ch), though it does return AX=0005h; this
	  has been documented by Novell
SeeAlso: AH=27h,AH=40h,AH=93h,INT 2F/AX=1108h,INT 2F/AX=1229h

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