nix-super/doc/manual/src/release-notes/rl-next.md

# Release X.Y (202?-??-??)

* A new function `builtins.readFileType` is available. It is similar to
  `builtins.readDir` but acts on a single file or directory.

* The `builtins.readDir` function has been optimized when encountering unknown
  file types from POSIX's `readdir`. In such cases the type of each file is/was
  discovered by making multiple syscalls. This change makes these operations
  lazy such that these lookups will only be performed if the attribute is used.
  This optimization effects a minority of filesystems and operating systems.
Move rl-next.md to rl-2.5.md 2021-12-13 17:48:44 +02:00			`# Release X.Y (202?-??-??)`
nix repl: make symlinks with the :bl command Requested by ppepino on the Matrix: https://matrix.to/#/!KqkRjyTEzAGRiZFBYT:nixos.org/$Tb32BS3rVE2BSULAX4sPm0h6CDewX2hClOTGzTC7gwM?via=nixos.org&via=matrix.org&via=nixos.dev This adds a new command, :bl, which works like :b but also creates a GC root symlink to the various derivation outputs. ckie@cookiemonster ~/git/nix -> ./outputs/out/bin/nix repl Welcome to Nix 2.6.0. Type :? for help. nix-repl> :l <nixpkgs> Added 16118 variables. nix-repl> :b runCommand "hello" {} "echo hi > $out" This derivation produced the following outputs: ./repl-result-out -> /nix/store/kidqq2acdpi05c4a9mlbg2baikmzik44-hello [1 built, 0.0 MiB DL] ckie@cookiemonster ~/git/nix -> cat ./repl-result-out hi 2022-04-18 20:21:47 +03:00
primop: add readFileType, optimize readDir Allows checking directory entry type of a single file/directory. This was added to optimize the use of `builtins.readDir` on some filesystems and operating systems which cannot detect this information using POSIX's `readdir`. Previously `builtins.readDir` would eagerly use system calls to lookup these filetypes using other interfaces; this change makes these operations lazy in the attribute values for each file with application of `builtins.readFileType`. 2023-01-22 21:45:02 +02:00			* A new function `builtins.readFileType` is available. It is similar to
			`builtins.readDir` but acts on a single file or directory.

			* The `builtins.readDir` function has been optimized when encountering unknown
			file types from POSIX's `readdir`. In such cases the type of each file is/was
			`discovered by making multiple syscalls. This change makes these operations`
			`lazy such that these lookups will only be performed if the attribute is used.`
			`This optimization effects a minority of filesystems and operating systems.`