| attrib | |
|---|---|
 TheReactOS attrib command | |
| Developers | Intel,IBM,Microsoft,DR,Datalight,Novell, Phil Brutsche, ReactOS Contributors |
| Initial release | 1984, 40–41 years ago (DOS version) |
| Operating system | ISIS-II,PC DOS,MS-DOS,MSX-DOS,SISNE plus,OS/2,eComStation,ArcaOS,Windows,DR DOS,ROM-DOS,FreeDOS,ReactOS,SymbOS |
| Platform | Cross-platform |
| Type | Command |
| License | FreeDOS, ReactOS:GPLv2 |
Incomputing,ATTRIB is acommand inIntelISIS-II,[1]DOS,IBMOS/2,[2]MicrosoftWindows[3] andReactOS[4] that allows the user to change various characteristics, or "attributes" of acomputer file ordirectory. The command is also available in theEFI shell.[5]
Severaloperating systems provided a set of modifiable file characteristics that could be accessed and changed through a low-levelsystem call. For example, as of releaseMS-DOS 4.0, the first sixbits of the file attributebyte indicated whether or not a file was read-only (as opposed to writeable), hidden, a system file, a volume label, a subdirectory, or if the file had been "archived" (with the bit being set if the file had changed since the last use of theBACKUP command).[6] However, initial releases of the operating system did not provide user-level method for reading or changing these values.[7]
The initial version of theATTRIB command for DOS was first included in version 3.0 ofPC DOS, with functionality limited to changing the read-only attribute.[7] Subsequent versions allowed the read-only, hidden, system and archive bits to be set.[8]MS-DOS version 3.3 added the capability of recursive searching through subdirectories to display attributes of specified files.[9]
Digital ResearchDR DOS 6.0[10] andDatalightROM-DOS[11] also include an implementation of theATTRIB command.
TheFreeDOS version was developed by Phil Brutsche and is licensed under theGPLv2.[12]
Setting the read-only bit of a file provided only partial protection against inadvertent deletion: while commands such asdel anderase would respect the attribute, other commands such asDELTREE did not.[13] Changing the system attribute was not possible in early versions of Windows, thus requiring use ofATTRIB.[13] Similarly, a system crash in early versions of Windows could lead to a situation where a temporary file had the read-only bit set and was additionally (and irrevocably) locked by the Windows OS; in this instance, booting into DOS (thus avoiding the Windows lock) and unsetting the read-only attribute withATTRIB was the recommended way of deleting the file.[14] Manipulating the archive bit allowed users to control which files were backed up using theBACKUP command.[7]
chattr, the equivalent on Unix and Linuxcacls, the Windows NTaccess control list (ACL) utility