Category: DOS kernel

INT 21 - DOS 2+ - "UNLINK" - DELETE FILE

	AH = 41h
	DS:DX -> ASCIZ filename (no wildcards, but see notes)
	CL = attribute mask for deletion (server call only, see notes)
Return: CF clear if successful
	    AX destroyed (DOS 3.3) AL seems to be drive of deleted file
	CF set on error
	    AX = error code (02h,03h,05h) (see #01680 at AH=59h/BX=0000h)
Notes:	(DOS 3.1+) wildcards are allowed if invoked via AX=5D00h, in which case
	  the filespec must be canonical (as returned by AH=60h), and only
	  files matching the attribute mask in CL are deleted
	DR DOS 5.0-6.0 returns error code 03h if invoked via AX=5D00h; DR DOS
	  3.41 crashes if called via AX=5D00h with wildcards
	DOS does not erase the file's data; it merely becomes inaccessible
	  because the FAT chain for the file is cleared
	deleting a file which is currently open may lead to filesystem
	  corruption.  Unless SHARE is loaded, DOS does not close the handles
	  referencing the deleted file, thus allowing writes to a nonexistant
	  file.
	under DR DOS and DR Multiuser DOS, this function will fail if the file
	  is currently open
	under the FlashTek X-32 DOS extender, the pointer is in DS:EDX
BUG:	DR DOS 3.41 crashes if called via AX=5D00h
SeeAlso: AH=13h,AX=4301h,AX=4380h,AX=5D00h,AH=60h,AX=7141h,AX=F244h
SeeAlso: INT 2F/AX=1113h