File System (jolt.fs)

jolt.fs is a file-system utility library over java.io.File. Its API mirrors babashka.fs where the two overlap, so the mental model transfers directly if you know babashka. Functions accept a String or a File; path-valued results are Files (Jolt's path value — there is no java.nio.file.Path). A handful of operations that need Path-level access — symbolic links and creation time — are not available on this host and throw a clean ex-info.

(require '[jolt.fs :as fs])

(fs/exists? "deps.edn")                       ; => true
(fs/create-dirs "target/classes/jolt")        ; => #object[File ...]
(fs/glob "src" "**.clj")                      ; => seq of File under src ending .clj
(fs/which "sh")                               ; => #object[File /bin/sh]

Coercion and nesting

  • file f — coerce a String/File to a File. With several args, nests: (file a b c) is a/b/c.

Predicates

Each takes a path and returns a boolean.

  • exists?, directory?, regular-file?, absolute?, relative?
  • readable?, writable?, executable?, hidden?
  • sym-link? — not supported on this host; throws ex-info.

Path pieces

  • file-name f — final path segment as a string.
  • parent f — parent as a File; nil at a root or a bare name.
  • extension f — extension without the dot; nil when there is none.
  • strip-ext f — file name without its extension.
  • absolutize f — absolute File (resolves against CWD, no symlink walk).
  • canonicalize f — canonical File (resolves ./.. and symlinks).
  • cwd [] — current working directory as a File.
  • relativize root other — path of other relative to root, as a File. Throws when other is not nested under root.
    (fs/extension "src/jolt/core.clj")            ; => "clj"
(fs/extension "Makefile")                     ; => nil
(fs/relativize "/a" "/a/b/c")                 ; => #object[File "b/c"]

Reading the tree

  • list-dir dir — immediate children as a (possibly empty) seq of Files.
  • walk root — depth-first seq of every file and directory under root, root first.
  • glob root pattern — files under root whose path relative to root matches a glob. ** crosses directory separators, * and ? stay within a segment, {a,b} alternates. Matches against the /-separated relative path; returns Files.
    (fs/glob "src" "**.clj")                      ; every .clj under src, recursively
(fs/glob "test" "*.{clj,ss}")                 ; top-level clj/ss files in test/

Creation and deletion

  • create-dir dir — one directory level; the parent must exist. Returns the File, throws if it can't be created.
  • create-dirs dir — a directory and any missing parents. Returns the File.
  • create-file f — an empty file. Returns the File.
  • create-temp-dir [{:keys [prefix] :or {prefix "jolt-"}}] — fresh directory under the system temp dir.
  • create-temp-file [{:keys [prefix suffix] :or {prefix "jolt-" suffix ".tmp"}}] — fresh file under the system temp dir.
  • delete f — a file or empty directory; throws when it doesn't exist.
  • delete-if-exists f — delete when present; true when something was deleted.
  • delete-tree root — a file or directory recursively. A missing path is a no-op.

Copy and move

  • size f — file size in bytes.
  • copy src dst [{:keys [replace-existing]}] — copy a regular file to dst. Throws if src is a directory (use copy-tree) or if dst exists without :replace-existing. Returns dst.
  • copy-tree src dst [opts] — copy a directory tree recursively. Returns dst.
  • move src dst [{:keys [replace-existing]}] — move (rename) src to dst. Falls back to copy-then-delete for a regular file when rename fails (cross-device). Returns dst.

Times

  • last-modified-time f — last-modified time as a java.time.Instant.
  • set-last-modified-time f inst — set the last-modified time from an Instant.
  • creation-time f — not supported on this host; throws ex-info.

Lookup

  • which nm — the first executable named nm on PATH, as a File, else nil.
  • read-link f — not supported on this host; throws ex-info.