EA DATA. SF
From Just Solve the File Format Problem
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'''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 [[HPFS Extended Attributes|extended file attributes]] that are supported by [[HPFS]] but not by FAT. | ||
Revision as of 19:31, 26 July 2022
EA DATA. SF is the filename of a special hidden file that may be present on FAT filesystems used by OS/2. It contains extended file attributes that are supported by HPFS but not by FAT.
Contents |
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
- Implementation of extended attributes on the FAT file system, section titled "Notes on the format of the EA datafile"
- Minerva II → 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
- EDM2: The Fundamentals of Extended Attributes
- EDM2: CPGuide - Extended Attributes
- US patent 5367671: System for accessing extended object attribute (EA) data through file name or EA handle linkages in path tables
