On Mar 24 21:42, Thomas Wolff wrote: > > > Am 24.03.2025 um 17:08 schrieb Jeffrey Altman: > > On 3/24/2025 10:25 AM, Martin Wege via Cygwin wrote: > > > Hello, > > > > > > another wishlist entry (old one): > > > read/write NTFS alternate data streams via openat(O_XATTR) > > > > From my perspective as a filesystem developer, Extended Attributes and > > Alternate Data Streams are different concepts which I believe are > > inappropriate to mix. > > > > Filesystems can implement one, the other, both or neither. > > > > An Extended Attribute is a name:value pair that can be attached to an > > inode. The size of individual values and the sum of the value sizes > > are often quite constrained because they are stored in the inode > > metadata. Copying an inode is guaranteed to copy the Extended Attributes. > > > > Alternate Data Streams are typically represented as independent > > inodes. The Alternate Data Stream namespace can be represented by a > > directory inode referenced from the file inode. Each ADS inode might > > have their own Extended Attributes to go along with the data stream. > > ACLs on ADS inodes can also be independent of the ACL on the primary > > inode depending upon the implementation. > > > > Therefore, I am reluctant to see openat(O_XATTR) be used to access > > alternate data streams. > > > > Jeffrey Altman > Why not use the Windows syntax? > cat file.txt:ads.txt > etc. (Was this discussed before?) > Thomas
The colon is a valid filename character in Cygwin, it will be converted to the UNICODE private use area: https://cygwin.com/cygwin-ug-net/using-specialnames.html#pathnames-specialchars Therefore you can't use the colon to specify streams. Corinna
