From a0a05786ae2ac7ae8cbd8551c75acaed821228f1 Mon Sep 17 00:00:00 2001
From: Simon Brooke <simon@journeyman.cc>
Date: Fri, 3 Apr 2026 14:17:55 +0100
Subject: [PATCH] Added tooling to create a standalone `binary`, using one neat
 hack!

---
 README.md               | 32 ++++++++++++++++++++++++--------
 project.clj             |  4 +++-
 resources/sh/builder.sh | 19 +++++++++++++++++++
 resources/sh/stub.sh    |  8 ++++++++
 4 files changed, 54 insertions(+), 9 deletions(-)
 create mode 100644 resources/sh/builder.sh
 create mode 100644 resources/sh/stub.sh

diff --git a/README.md b/README.md
index 47aee7e..dfa7339 100644
--- a/README.md
+++ b/README.md
@@ -82,9 +82,32 @@ implement one.
 
 You are of course welcome to fork the project and do whatever you like with it!
 
+
+### Building
+
+Build with
+
+    lein uberjar
+
+This will build a jar file in `target/uberjar/beowulf-VERSION-standalone.jar`,
+where VERSION is the current version number.
+
+On UNIX platforms (includeing Linux), you can build a standalone binary by 
+invoking a script, `resources/sh/builder.sh`, *after* invoking `lein uberjar`, 
+so:
+
+    lein uberjar
+    sh resources/sh/builder.sh
+
+This should build a standalone binary in `target/beowulf`.
+
+In order to be able to invoke this binary just like any other program, move it
+to somewhere on your path, idealy `${HOME}/bin` or `/usr/local/bin`.
+
 ### Invoking
 
-Invoke with
+If you have not built and installed the standalone binary, you may invoke the
+uberjar with
 
     java -jar target/uberjar/beowulf-0.3.1-standalone.jar --help
 
@@ -103,13 +126,6 @@ Command line arguments as follows:
 
 To end a session, type `STOP` at the command prompt.
 
-### Building and Invoking
-
-Build with
-
-    lein uberjar
-
-
 ### Reader macros
 
 Currently `SETQ` and `DEFUN` are implemented as reader macros, sort of. It would
diff --git a/project.clj b/project.clj
index 64742f2..c9b7fc5 100644
--- a/project.clj
+++ b/project.clj
@@ -25,7 +25,8 @@
   :main  beowulf.core
   :plugins [[lein-cloverage "1.2.2"]
             [lein-codox "0.10.8"]
-            [lein-environ "1.1.0"]]
+            [lein-environ "1.1.0"]
+            [lein-shell "0.5.0"]]
   :profiles {:jar {:aot :all}
              :uberjar {:aot :all}
              :dev {:resource-paths ["resources"]}}
@@ -36,6 +37,7 @@
                   ["clean"]
                   ["codox"]
                   ["uberjar"]
+                  ;; ["shell" "resources/sh/builder.sh" ]
                   ["change" "version" "leiningen.release/bump-version"]
                   ["vcs" "commit"]]
   :target-path "target/%s"
diff --git a/resources/sh/builder.sh b/resources/sh/builder.sh
new file mode 100644
index 0000000..2650eb6
--- /dev/null
+++ b/resources/sh/builder.sh
@@ -0,0 +1,19 @@
+#!/bin/sh
+
+# Create an executable from an arbitrary uberjar file.
+# I am grateful to
+# https://coderwall.com/p/ssuaxa/how-to-make-a-jar-file-linux-executable
+# for this extremely cute trick. This version is intended for
+# Leiningen projects, but if you can understand this you can
+# easily hack it for the conventions of any build tool you use.
+#
+# Simon Brooke, simon@journeyman.cc, 20260403
+
+BASEDIR=$(dirname "$0")
+PROJECT=beowulf
+BINARY=target/${PROJECT}
+
+cat ${BASEDIR}/stub.sh \
+    target/uberjar/${PROJECT}*-standalone.jar > ${BINARY} \
+    && chmod +x ${BINARY}  
+
diff --git a/resources/sh/stub.sh b/resources/sh/stub.sh
new file mode 100644
index 0000000..689b831
--- /dev/null
+++ b/resources/sh/stub.sh
@@ -0,0 +1,8 @@
+#!/bin/sh
+MYSELF=`which "$0" 2>/dev/null`
+[ $? -gt 0 -a -f "$0" ] && MYSELF="./$0"
+java=java
+if test -n "$JAVA_HOME"; then
+    java="$JAVA_HOME/bin/java"
+fi
+exec "$java" $java_args -jar $MYSELF "$@"