EA DATA. SF - Revision history

Jsummers at 12:04, 7 June 2024

2024-06-07T12:04:54Z

Thorsted at 20:18, 26 July 2022

2022-07-26T20:18:46Z

Thorsted at 19:31, 26 July 2022

2022-07-26T19:31:38Z

Jsummers: Created page with "{{FormatInfo |formattype=electronic |subcat=Metadata |extensions={{ext| sf}} }} '''EA DATA. SF''' is the filename of a special hidden file that may be present on FAT files..."

2021-03-18T20:51:03Z

Created page with "{{FormatInfo |formattype=electronic |subcat=Metadata |extensions={{ext| sf}} }} '''EA DATA. SF''' is the filename of a special hidden file that may be present on FAT files..."

New page

{{FormatInfo
|formattype=electronic
|subcat=Metadata
|extensions={{ext| sf}}
}}
'''EA DATA. SF''' is the filename of a special hidden file that may be present on [[FAT]] filesystems used by OS/2. It contains [[HPFS Extended Attributes|extended file attributes]] that are supported by [[HPFS]] but not by FAT.

== Format details ==
The EA DATA file is highly "fragmented", in such a way as to keep a user file's attributes physically close to its data.

Accurately decoding an EA DATA file can only be done in the context of the [[FAT]] filesystem that contains it. For a user file that has extended attributes, its FAT directory entry contains a special nonzero identifier at offset 20 (from the beginning of the filename field). These identifiers refer to sections of the EA DATA file.

== Specifications ==
* [https://www.tavi.co.uk/os2pages/eadata.html Implementation of extended attributes on the FAT file system], section titled "Notes on the format of the EA datafile"
** [https://archive.org/details/minerva2 Minerva II] → [https://archive.org/download/minerva2/minerva2.zip/minerva2%2FOS2%2FEADATA.ARJ OS2/EADATA.ARJ] - Same information

== Sample files ==
* Often found on OS/2 floppy disk images. For example, see [[LoadDskF/SaveDskF#Sample files]].

== Links ==
* [[Wikipedia: File Allocation Table#Extended Attributes]]
* [http://www.edm2.com/index.php/The_Fundamentals_of_Extended_Attributes EDM2: The Fundamentals of Extended Attributes]
* [http://www.edm2.com/index.php/CPGuide_-_Extended_Attributes EDM2: CPGuide - Extended Attributes]
* [https://patents.google.com/patent/US5367671 US patent 5367671]: System for accessing extended object attribute (EA) data through file name or EA handle linkages in path tables

[[Category:File formats with extension .sf]]
[[Category:Filesystem]]
[[Category:OS/2]]
[[Category:File formats with a distinctive filename]]

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 |extensions={{ext| sf}}
 }}
-'''EA DATA. SF''' is the filename of a special hidden file that may be present on [[FAT]] filesystems used by OS/2. It contains [[HPFS Extended Attributes|extended file attributes]] that are supported by [[HPFS]] but not by FAT.
+'''EA DATA. SF''' is the filename of a special hidden file that may be present on [[FAT]] filesystems used by OS/2. It contains [[OS/2 extended attributes|extended file attributes]] that are supported by [[HPFS]] but not by FAT.
 == Format details ==

@@ Line 2: / Line 2: @@
 |formattype=electronic
 |subcat=Metadata
-|extensions={{ext|sf}}
+|extensions={{ext| sf}}
 }}
 '''EA DATA. SF''' is the filename of a special hidden file that may be present on [[FAT]] filesystems used by OS/2. It contains [[HPFS Extended Attributes|extended file attributes]] that are supported by [[HPFS]] but not by FAT.