diff --git a/.clj-kondo/config.edn b/.clj-kondo/config.edn
index 8bd021f1..3ec45fb6 100644
--- a/.clj-kondo/config.edn
+++ b/.clj-kondo/config.edn
@@ -1 +1,3 @@
-{:lint-as {me.raynes.conch/let-programs clojure.core/let}}
+{:lint-as {me.raynes.conch/let-programs clojure.core/let
+           babashka.impl.File/gen-wrapper-fn clojure.core/def
+           babashka.impl.File/gen-wrapper-fn-2 clojure.core/def}}
diff --git a/README.md b/README.md
index 43ae53a8..c26a376b 100644
--- a/README.md
+++ b/README.md
@@ -95,24 +95,46 @@ You may also download a binary from [Github](https://github.com/borkdude/babashk
 ## Usage
 
 ``` shellsession
-bb [ --help ] | [ --version ] | ( [ -i ] [ -o ] | [ -io ] ) [ --stream ] ( expression | -f <file> )
-```
+$ bb --help
+Usage: bb [ --help ] | [ --version ] | ( [ -i ] [ -o ] | [ -io ] ) [ --stream ] ( expression | -f <file> )
 
-Type `bb --help` to see a full explanation of the options.
+Options:
+
+  --help: print this help text.
+  --version: print the current version of babashka.
+
+  -i: read shell input into a list of strings instead of reading EDN.
+  -o: write shell output instead of EDN.
+  -io: combination of -i and -o.
+  --stream: stream over lines or EDN values from stdin. Combined with -i *in* becomes a single line per iteration.
+  --file or -f: read expressions from file instead of argument wrapped in an implicit do.
+  --time: print execution time before exiting.
+```
 
 The `clojure.core` functions are accessible without a namespace alias.
 
 The following Clojure namespaces are required by default and only available
-through the aliases:
+through the aliases. If not all vars are available, they are enumerated
+explicitly.
 
 - `clojure.string` aliased as `str`
 - `clojure.set` aliased as `set`
-- `clojure.edn` aliased as `edn` (only `read-string` is available)
-- `clojure.java.shell` aliases as `shell` (only `sh` is available)
+- `clojure.edn` aliased as `edn`:
+  - `read-string`
+- `clojure.java.shell` aliases as `shell`:
+  - `sh`
+- `clojure.java.io` aliased as `io`:
+  - `as-relative-path`, `copy`, `delete-file`, `file`
 
 From Java the following is available:
 
 - `System`: `exit`, `getProperty`, `setProperty`, `getProperties`, `getenv`
+- `File`: `.canRead`, `.canWrite`, `.delete`, `.deleteOnExit`, `.exists`,
+  `.getAbsoluteFile`, `.getCanonicalFile`, `.getCanonicalPath`, `.getName`,
+  `.getParent`, `.getParentFile`, `.getPath`, `.isAbsolute`, `.isDirectory`,
+  `.isFile`, `.isHidden`, `.lastModified`, `.length`, `.list`, `.listFiles`,
+  `.mkdir`, `.mkdirs`, `.renameTo`, `.setLastModified`, `.setReadOnly`,
+  `.setReadable`, `.toPath`, `.toURI`.
 
 Special vars:
 
diff --git a/src/babashka/impl/File.clj b/src/babashka/impl/File.clj
new file mode 100644
index 00000000..641de24d
--- /dev/null
+++ b/src/babashka/impl/File.clj
@@ -0,0 +1,80 @@
+(ns babashka.impl.File
+  (:refer-clojure :exclude [list])
+  (:require [clojure.java.io :as io]
+            [clojure.string :as str]))
+
+(set! *warn-on-reflection* true)
+;; also see https://gist.github.com/plexus/68594ba9b5e3f0d63fe84dcae31c4a53
+
+(defmacro gen-wrapper-fn [method-name]
+  `(defn ~method-name {:bb/export true}
+     [~(with-meta 'x {:tag 'java.io.File})]
+     (~(symbol (str "." method-name)) ~'x)))
+
+(defmacro gen-wrapper-fn-2 [method-name]
+  `(defn ~method-name {:bb/export true}
+     [~(with-meta 'x {:tag 'java.io.File}) ~'y]
+     (~(symbol (str "." method-name)) ~'x ~'y)))
+
+(gen-wrapper-fn canRead)
+(gen-wrapper-fn canWrite)
+(gen-wrapper-fn delete)
+(gen-wrapper-fn deleteOnExit)
+(gen-wrapper-fn exists)
+(gen-wrapper-fn getAbsoluteFile)
+(gen-wrapper-fn getCanonicalFile)
+(gen-wrapper-fn getCanonicalPath)
+(gen-wrapper-fn getName)
+(gen-wrapper-fn getParent)
+(gen-wrapper-fn getParentFile)
+(gen-wrapper-fn getPath)
+(gen-wrapper-fn isAbsolute)
+(gen-wrapper-fn isDirectory)
+(gen-wrapper-fn isFile)
+(gen-wrapper-fn isHidden)
+(gen-wrapper-fn lastModified)
+(gen-wrapper-fn length)
+(gen-wrapper-fn list)
+(gen-wrapper-fn listFiles)
+(gen-wrapper-fn mkdir)
+(gen-wrapper-fn mkdirs)
+(gen-wrapper-fn-2 renameTo)
+(defn setExecutable
+  ([^java.io.File f b]
+   (.setExecutable f b))
+  ([^java.io.File f b ownerOnly]
+   (.setExecutable f b ownerOnly)))
+(gen-wrapper-fn-2 setLastModified)
+(gen-wrapper-fn-2 setReadable)
+(gen-wrapper-fn setReadOnly)
+(defn setWritable
+  ([^java.io.File f b]
+   (.setWritable f b))
+  ([^java.io.File f b ownerOnly]
+   (.setWritable f b ownerOnly)))
+(gen-wrapper-fn toPath)
+(gen-wrapper-fn toURI)
+
+(def bindings
+  (reduce (fn [acc [k v]]
+            (if (-> v meta :bb/export)
+              (assoc acc (symbol (str "." k))
+                     @v)
+              acc))
+          {}
+          (ns-publics *ns*)))
+
+(comment
+  (canRead (clojure.java.io/file "README.md"))
+  (canWrite (clojure.java.io/file "README.md"))
+  (exists (clojure.java.io/file "README.md"))
+  (renameTo (io/file "/tmp/script2.clj") (io/file "/tmp/script.clj"))
+  (.setWritable (io/file "/tmp/script.clj") true true)
+  (meta #'toURI)
+  (first bindings)
+  (get bindings '.length)
+  (get bindings '.canWrite)
+  (meta #'canWrite)
+  ;; for README.md:
+  (str/join ", " (map #(format "`%s`" %) (sort (keys bindings))))
+  )
diff --git a/src/babashka/main.clj b/src/babashka/main.clj
index ebd5576c..1b0e02fc 100644
--- a/src/babashka/main.clj
+++ b/src/babashka/main.clj
@@ -5,7 +5,8 @@
    [clojure.java.io :as io]
    [clojure.java.shell :as shell]
    [clojure.string :as str]
-   [sci.core :as sci])
+   [sci.core :as sci]
+   [babashka.impl.File :as File])
   (:gen-class))
 
 (set! *warn-on-reflection* true)
@@ -111,23 +112,35 @@
   (throw (ex-info "" {:bb/exit-code n})))
 
 (def bindings
-  {'run! run!
-   'shell/sh shell/sh
-   'csh shell/sh ;; backwards compatibility, deprecated
-   'namespace namespace
-   'slurp slurp
-   'spit spit
-   'pmap pmap
-   'print print
-   'pr-str pr-str
-   'prn prn
-   'println println
-   'edn/read-string edn/read-string
-   'System/getenv get-env
-   'System/getProperty get-property
-   'System/setProperty set-property
-   'System/getProperties get-properties
-   'System/exit exit})
+  (merge {'run! run!
+          'shell/sh shell/sh
+          'csh shell/sh ;; backwards compatibility, deprecated
+          'namespace namespace
+          'slurp slurp
+          'spit spit
+          'pmap pmap
+          'print print
+          'pr-str pr-str
+          'prn prn
+          'println println
+
+          ;; clojure.java.io
+          'io/as-relative-path io/as-relative-path
+          'io/copy io/copy
+          'io/delete-file io/delete-file
+          'io/file io/file
+          ;; '.canRead File/canRead
+          ;; '.canWrite File/canWrite
+          ;; '.exists File/exists
+          ;; '.delete File/delete
+
+          'edn/read-string edn/read-string
+          'System/getenv get-env
+          'System/getProperty get-property
+          'System/setProperty set-property
+          'System/getProperties get-properties
+          'System/exit exit}
+         File/bindings))
 
 (defn read-edn []
   (edn/read {;;:readers *data-readers*
diff --git a/test/babashka/main_test.clj b/test/babashka/main_test.clj
index 5402d5fd..353fb7a4 100644
--- a/test/babashka/main_test.clj
+++ b/test/babashka/main_test.clj
@@ -110,3 +110,7 @@
   ;; THIS TEST REQUIRES:
   ;; export BABASHKA_PRELOADS='(defn __bb__foo [] "foo") (defn __bb__bar [] "bar")'
   (is (= "foobar" (bb nil "(str (__bb__foo) (__bb__bar))"))))
+
+(deftest io-test
+  (is (true? (bb nil "(.exists (io/file \"README.md\"))")))
+  (is (true? (bb nil "(.canWrite (io/file \"README.md\"))"))))