Fleck is a Clojure-like LISP that runs wherever Bash is.
curl -s https://chr15m.github.io/flk/flk > flk && chmod 755 flk
./flk
Examples | Reference | FAQ | make-a-lisp
$ echo ‘(println “Hello world!”) (println “Hostname:” (sh* “hostname”)))’ > example.clj
$ ./flk example.clj
Hello world!
Hostname: diziet
Now you can use a humble LISP to do Bash things.
Bash as a scripting language has many edges, but it is everywhere.
Fleck attempts to round off the edges.
Almost all of this code is from the make-a-LISP project. All I’ve done is put together a simple Makefile to package it up into an easily deployable single-file bash script.
A list of macros and functions that are present in Fleck.
Built-ins
This is the set of built-ins from the make-a-lisp project.
These more or less work but are generally more limited in functionality than their Clojure equivalents.
For example the addition function (+) can only add two numbers at a time.
def! | defmacro! | if | do | fn* | try* | sh* | let* | quote | quasiquote | macroexpand | type | = | throw | nil? | true? | false? | string? | symbol | symbol? | keyword | keyword? | number? | fn? | macro? | pr-str | str | prn | println | readline | read-string | slurp | = | + | – | * | / | time-ms | list | list? | vector | vector? | hash-map | map? | assoc | dissoc | get | contains? | keys | vals | sequential? | cons | concat | nth | first | rest | empty? | count | apply | map | conj | seq | with-meta | meta | atom | atom? | deref | reset! | swap!
Extras
These functions are defined in Fleck itself or pulled in from the mal/lib/ folder.
pprint | str-replace | str-split
(str-replace STRING FIND REPLACE) – Replace all occurrences of the string FIND in STRING with the string REPLACE.
(str-split STRING SPLIT-CHARACTER) – Split STRING into a list of strings on the single characters SPLIT-CHARACTER.
Aliases
These are wrappers around the limited internal versions of the make-a-lisp macros and functions and are much more limited than the Clojure equivalents.
let | when | def | fn | defn
You can compile your Fleck script to a one which runs in pure Bash without Fleck.
This works by bundling the Fleck sources with your script.
Say you have a Fleck script called wow.clj, you can compile it as follows.
make DEST=wow INSERT=./wow.clj NOREPL=1
This will produce a new standalone executable script called wow which will bundle wow.clj into Fleck and it will be called at run time.
Think of this as homoiconic Bash rather than Clojure, and code as if you’re in Bash.
Will my favourite piece of Clojure run in this?
No, it’s bash.
Why can’t I add more than 2 numbers together?
It’s bash. Try invoking bc: (sh* “bc ‘1 + 2 + 3 + 4′”)
Where are the floating point numbers?
It’s bash. Try invoking bc: (sh* “bc ‘3 + 0.1415926′”)
Why can’t I iterate on a string?
It’s bash. Try (seq “somestring”).
How do I do destructuring?
You can’t.
Why is it called Fleck?
At 36k and running on any machine with Bash, the name seemed appropriate.
fleck
n. A tiny mark or spot.
n. A small bit or flake.
