156 lines
4.2 KiB
Nix
156 lines
4.2 KiB
Nix
# Functions for querying information about the filesystem
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# without copying any files to the Nix store.
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{ lib }:
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# Tested in lib/tests/filesystem.sh
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let
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inherit (builtins)
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readDir
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pathExists
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;
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inherit (lib.filesystem)
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pathType
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;
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in
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{
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/*
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The type of a path. The path needs to exist and be accessible.
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The result is either "directory" for a directory, "regular" for a regular file, "symlink" for a symlink, or "unknown" for anything else.
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Type:
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pathType :: Path -> String
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Example:
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pathType /.
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=> "directory"
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pathType /some/file.nix
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=> "regular"
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*/
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pathType =
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builtins.readFileType or
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# Nix <2.14 compatibility shim
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(path:
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if ! pathExists path
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# Fail irrecoverably to mimic the historic behavior of this function and
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# the new builtins.readFileType
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then abort "lib.filesystem.pathType: Path ${toString path} does not exist."
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# The filesystem root is the only path where `dirOf / == /` and
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# `baseNameOf /` is not valid. We can detect this and directly return
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# "directory", since we know the filesystem root can't be anything else.
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else if dirOf path == path
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then "directory"
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else (readDir (dirOf path)).${baseNameOf path}
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);
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/*
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Whether a path exists and is a directory.
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Type:
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pathIsDirectory :: Path -> Bool
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Example:
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pathIsDirectory /.
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=> true
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pathIsDirectory /this/does/not/exist
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=> false
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pathIsDirectory /some/file.nix
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=> false
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*/
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pathIsDirectory = path:
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pathExists path && pathType path == "directory";
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/*
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Whether a path exists and is a regular file, meaning not a symlink or any other special file type.
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Type:
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pathIsRegularFile :: Path -> Bool
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Example:
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pathIsRegularFile /.
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=> false
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pathIsRegularFile /this/does/not/exist
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=> false
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pathIsRegularFile /some/file.nix
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=> true
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*/
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pathIsRegularFile = path:
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pathExists path && pathType path == "regular";
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/*
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A map of all haskell packages defined in the given path,
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identified by having a cabal file with the same name as the
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directory itself.
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Type: Path -> Map String Path
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*/
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haskellPathsInDir =
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# The directory within to search
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root:
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let # Files in the root
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root-files = builtins.attrNames (builtins.readDir root);
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# Files with their full paths
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root-files-with-paths =
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map (file:
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{ name = file; value = root + "/${file}"; }
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) root-files;
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# Subdirectories of the root with a cabal file.
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cabal-subdirs =
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builtins.filter ({ name, value }:
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builtins.pathExists (value + "/${name}.cabal")
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) root-files-with-paths;
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in builtins.listToAttrs cabal-subdirs;
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/*
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Find the first directory containing a file matching 'pattern'
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upward from a given 'file'.
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Returns 'null' if no directories contain a file matching 'pattern'.
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Type: RegExp -> Path -> Nullable { path : Path; matches : [ MatchResults ]; }
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*/
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locateDominatingFile =
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# The pattern to search for
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pattern:
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# The file to start searching upward from
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file:
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let go = path:
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let files = builtins.attrNames (builtins.readDir path);
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matches = builtins.filter (match: match != null)
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(map (builtins.match pattern) files);
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in
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if builtins.length matches != 0
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then { inherit path matches; }
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else if path == /.
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then null
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else go (dirOf path);
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parent = dirOf file;
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isDir =
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let base = baseNameOf file;
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type = (builtins.readDir parent).${base} or null;
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in file == /. || type == "directory";
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in go (if isDir then file else parent);
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/*
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Given a directory, return a flattened list of all files within it recursively.
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Type: Path -> [ Path ]
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*/
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listFilesRecursive =
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# The path to recursively list
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dir:
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lib.flatten (lib.mapAttrsToList (name: type:
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if type == "directory" then
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lib.filesystem.listFilesRecursive (dir + "/${name}")
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else
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dir + "/${name}"
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) (builtins.readDir dir));
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}
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