INT 21 - DOS 1+ - DELETE FILE USING FCBsee File Control Block AH = 13h DS:DX -> unopened FCBsee File Control Block (see #01345), filename filled with template for deletion ('?' wildcards allowed) Return: AL = status 00h one or more files successfully deleted FFh no matching files or all were read-only or locked Notes: DOS 1.25+ deletes everything in the current directory (including subdirectories) and sets the first byte of the name to 00h (entry never used) instead of E5h if called on an extended FCBsee File Control Block with filename '???????????' and bits 0-4 of the attribute set (bits 1 and 2 for DOS 1.x). This may have originally been an optimization to minimize directory searching after a mass deletion (DOS 1.25+ stop the directory search upon encountering a never-used entry), but can corrupt the filesystem under DOS 2+ because subdirectories are removed without deleting the files they contain. currently-open files should not be deleted MS-DOS allows deletion of read-only files with an extended FCBsee File Control Block, whereas Novell NetWare, DR DOS 6, and Novell DOS 7/OpenDOS 7.01 do not this function generates a trap "D" under OS/2 v4.x (Warp4) when called on an HPFS partition with a wildcard in the filename; it operates correctly on FATsee File Allocation Table partitions and when called without wildcards SeeAlso: AH=41h,INT 2F/AX=1113h