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====== Int 21H, AH=43H, AL=01H ======

===== Version =====

2 and higher

===== Brief =====

"CHMOD" - SET FILE ATTRIBUTES

===== Family API =====


===== Input =====

        AX = 4301h
        CX = new file attributes (see #01420)
        DS:DX -> ASCIZ filename

===== Return =====

 CF clear if successful
            AX destroyed
        CF set on error
            AX = error code (01h,02h,03h,05h) (see #01680 at AH=59h)
===== Macro =====


===== Notes =====

will not change volume label or directory attribute bits, but will change the other attribute bits of a directory (the directory bit must be cleared to successfully change the other attributes of a directory, but the directory will not be changed to a normal file as a result)
          
MS-DOS 4.01 reportedly closes the file if it is currently open
        
for security reasons, the Novell NetWare execute-only bit can never be cleared; the file must be deleted and recreated
          
under the FlashTek X-32 DOS extender, the filename pointer is in DS:EDX
        
DOS 5.0 SHARE will close the file if it is currently open in sharing-compatibility mode, otherwise a sharing violation critical error is generated if the file is currently open
          
DR DOS 3.41/5.0 will silently ignore attempts to change the 'directory' attribute bit

Bitfields for file attributes:

^ Bit(s) ^ Description ^
| 7 | shareable (Novell NetWare) |
| 7 | pending deleted files (Novell DOS, OpenDOS) |
| 6 | unused |
| 5 | archive |
| 4 | directory |
| 3 | volume label |
| 3 | execute-only (Novell NetWare) |
| 2 | system |
| 1 | hidden |
| 0 | read-only |

===== See also =====

AX=[[en:docs:dos:api:int21:43:00|4300h]],AX=[[en:docs:dos:api:int21:71:43|7143h]],INT 2F/AX=110Eh

===== Note =====

Text based on [[http://www.cs.cmu.edu/~ralf/files.html|Ralf Brown Interrupt List Release 61]]

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