From e24a2fa37684deca503449717cb72992d98b01d6 Mon Sep 17 00:00:00 2001
From: Nicolas Boulenguez <nicolas.boulenguez@free.fr>
Date: Sat, 18 Apr 2026 18:39:55 +0200
Subject: [PATCH 01/10] awk: the -O option is enabled by default

---
 impls/awk/run | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/impls/awk/run b/impls/awk/run
index 9c3061869f..035bed1e3f 100755
--- a/impls/awk/run
+++ b/impls/awk/run
@@ -1,2 +1,2 @@
 #!/usr/bin/env bash
-exec awk -O -f $(dirname $0)/${STEP:-stepA_mal}.awk "${@}"
+exec awk -f $(dirname $0)/${STEP:-stepA_mal}.awk "${@}"

From 7b8fe27526e5382522bc4535cbd83b3d12688268 Mon Sep 17 00:00:00 2001
From: Nicolas Boulenguez <nicolas.boulenguez@free.fr>
Date: Sat, 18 Apr 2026 18:41:55 +0200
Subject: [PATCH 02/10] vhdl: clean vhdl_argv.tmp in Makefile instead of run

---
 impls/vhdl/Makefile    | 2 +-
 impls/vhdl/run_vhdl.sh | 6 ------
 2 files changed, 1 insertion(+), 7 deletions(-)

diff --git a/impls/vhdl/Makefile b/impls/vhdl/Makefile
index e76b8e104a..5e9fe86a7d 100644
--- a/impls/vhdl/Makefile
+++ b/impls/vhdl/Makefile
@@ -32,4 +32,4 @@ $(BINS): %: %.o
 	if [ "$@" = "stepA_mal" ]; then mv stepa_mal $@; fi
 
 clean:
-	rm -f $(OBJS) $(BINS) $(OTHER_OBJS) work-obj93.cf mal
+	rm -f $(OBJS) $(BINS) $(OTHER_OBJS) work-obj93.cf mal vhdl_argv.tmp
diff --git a/impls/vhdl/run_vhdl.sh b/impls/vhdl/run_vhdl.sh
index 1cc8e3bf9f..14fbd35131 100755
--- a/impls/vhdl/run_vhdl.sh
+++ b/impls/vhdl/run_vhdl.sh
@@ -5,12 +5,6 @@
 # vhdl_argv.tmp, and read the content of that file at the beginning of the VHDL
 # program.
 
-cleanup() {
-    trap - TERM QUIT INT EXIT
-    rm -f vhdl_argv.tmp
-}
-trap "cleanup" TERM QUIT INT EXIT
-
 bin="$1"
 shift
 

From 7c9f49c74535ced65bf31844d5974ed7da780651 Mon Sep 17 00:00:00 2001
From: Nicolas Boulenguez <nicolas.boulenguez@free.fr>
Date: Sat, 18 Apr 2026 18:57:02 +0200
Subject: [PATCH 03/10] Remove unnecessary shebangs or execution rights

Shebangs are convenient, but not portable, and they increase the
complexity.  Most were ignored for the more general "run" script.
---
 examples/clojurewest2014.mal                          | 0
 examples/presentation.mal                             | 0
 impls/ada/Dockerfile                                  | 0
 impls/bash/step0_repl.sh                              | 2 --
 impls/bash/step1_read_print.sh                        | 2 --
 impls/bash/step2_eval.sh                              | 2 --
 impls/bash/step3_env.sh                               | 2 --
 impls/bash/step4_if_fn_do.sh                          | 2 --
 impls/bash/step5_tco.sh                               | 2 --
 impls/bash/step6_file.sh                              | 2 --
 impls/bash/step7_quote.sh                             | 2 --
 impls/bash/step8_macros.sh                            | 2 --
 impls/bash/step9_try.sh                               | 2 --
 impls/bash/stepA_mal.sh                               | 2 --
 impls/basic/step0_repl.in.bas                         | 0
 impls/basic/step1_read_print.in.bas                   | 0
 impls/basic/step2_eval.in.bas                         | 0
 impls/basic/step3_env.in.bas                          | 0
 impls/basic/step4_if_fn_do.in.bas                     | 0
 impls/basic/step5_tco.in.bas                          | 0
 impls/basic/step6_file.in.bas                         | 0
 impls/basic/step7_quote.in.bas                        | 0
 impls/basic/step8_macros.in.bas                       | 0
 impls/basic/step9_try.in.bas                          | 0
 impls/basic/stepA_mal.in.bas                          | 0
 impls/crystal/step0_repl.cr                           | 2 --
 impls/crystal/step1_read_print.cr                     | 2 --
 impls/crystal/step2_eval.cr                           | 2 --
 impls/crystal/step3_env.cr                            | 2 --
 impls/crystal/step4_if_fn_do.cr                       | 2 --
 impls/crystal/step5_tco.cr                            | 2 --
 impls/crystal/step6_file.cr                           | 2 --
 impls/crystal/step7_quote.cr                          | 2 --
 impls/crystal/step8_macros.cr                         | 2 --
 impls/crystal/step9_try.cr                            | 2 --
 impls/crystal/stepA_mal.cr                            | 2 --
 impls/factor/step0_repl/step0_repl.factor             | 0
 impls/factor/step1_read_print/step1_read_print.factor | 0
 impls/factor/step2_eval/step2_eval.factor             | 0
 impls/factor/step3_env/step3_env.factor               | 0
 impls/factor/step4_if_fn_do/step4_if_fn_do.factor     | 0
 impls/factor/step5_tco/step5_tco.factor               | 0
 impls/factor/step6_file/step6_file.factor             | 0
 impls/factor/step7_quote/step7_quote.factor           | 0
 impls/factor/step8_macros/step8_macros.factor         | 0
 impls/factor/step9_try/step9_try.factor               | 0
 impls/factor/stepA_mal/stepA_mal.factor               | 0
 impls/hy/run                                          | 2 +-
 impls/hy/step0_repl.hy                                | 2 --
 impls/hy/step1_read_print.hy                          | 2 --
 impls/hy/step2_eval.hy                                | 2 --
 impls/hy/step3_env.hy                                 | 2 --
 impls/hy/step4_if_fn_do.hy                            | 2 --
 impls/hy/step5_tco.hy                                 | 2 --
 impls/hy/step6_file.hy                                | 2 --
 impls/hy/step7_quote.hy                               | 2 --
 impls/hy/step8_macros.hy                              | 2 --
 impls/hy/step9_try.hy                                 | 2 --
 impls/hy/stepA_mal.hy                                 | 2 --
 impls/julia/step0_repl.jl                             | 2 --
 impls/julia/step1_read_print.jl                       | 2 --
 impls/julia/step2_eval.jl                             | 2 --
 impls/julia/step3_env.jl                              | 2 --
 impls/julia/step4_if_fn_do.jl                         | 2 --
 impls/julia/step5_tco.jl                              | 2 --
 impls/julia/step6_file.jl                             | 2 --
 impls/julia/step7_quote.jl                            | 2 --
 impls/julia/step8_macros.jl                           | 2 --
 impls/julia/step9_try.jl                              | 2 --
 impls/julia/stepA_mal.jl                              | 2 --
 impls/lua/step0_repl.lua                              | 2 --
 impls/lua/step1_read_print.lua                        | 2 --
 impls/lua/step2_eval.lua                              | 2 --
 impls/lua/step3_env.lua                               | 2 --
 impls/lua/step4_if_fn_do.lua                          | 2 --
 impls/lua/step5_tco.lua                               | 2 --
 impls/lua/step6_file.lua                              | 2 --
 impls/lua/step7_quote.lua                             | 2 --
 impls/lua/step8_macros.lua                            | 2 --
 impls/lua/step9_try.lua                               | 2 --
 impls/lua/stepA_mal.lua                               | 2 --
 impls/make/reader.mk                                  | 0
 impls/perl/step0_repl.pl                              | 2 --
 impls/perl/step1_read_print.pl                        | 2 --
 impls/perl/step2_eval.pl                              | 2 --
 impls/perl/step3_env.pl                               | 2 --
 impls/perl/step4_if_fn_do.pl                          | 2 --
 impls/perl/step5_tco.pl                               | 2 --
 impls/perl/step6_file.pl                              | 2 --
 impls/perl/step7_quote.pl                             | 2 --
 impls/perl/step8_macros.pl                            | 2 --
 impls/perl/step9_try.pl                               | 2 --
 impls/perl/stepA_mal.pl                               | 2 --
 impls/plpgsql/init.sql                                | 0
 impls/racket/step0_repl.rkt                           | 1 -
 impls/racket/step1_read_print.rkt                     | 1 -
 impls/racket/step2_eval.rkt                           | 1 -
 impls/racket/step3_env.rkt                            | 1 -
 impls/racket/step4_if_fn_do.rkt                       | 1 -
 impls/racket/step5_tco.rkt                            | 1 -
 impls/racket/step6_file.rkt                           | 1 -
 impls/racket/step7_quote.rkt                          | 1 -
 impls/racket/step8_macros.rkt                         | 1 -
 impls/racket/step9_try.rkt                            | 1 -
 impls/racket/stepA_mal.rkt                            | 1 -
 impls/wasm/run                                        | 2 +-
 impls/wasm/run.js                                     | 4 +---
 107 files changed, 3 insertions(+), 148 deletions(-)
 mode change 100755 => 100644 examples/clojurewest2014.mal
 mode change 100755 => 100644 examples/presentation.mal
 mode change 100755 => 100644 impls/ada/Dockerfile
 mode change 100755 => 100644 impls/bash/step0_repl.sh
 mode change 100755 => 100644 impls/bash/step1_read_print.sh
 mode change 100755 => 100644 impls/bash/step2_eval.sh
 mode change 100755 => 100644 impls/bash/step3_env.sh
 mode change 100755 => 100644 impls/bash/step4_if_fn_do.sh
 mode change 100755 => 100644 impls/bash/step5_tco.sh
 mode change 100755 => 100644 impls/bash/step6_file.sh
 mode change 100755 => 100644 impls/bash/step7_quote.sh
 mode change 100755 => 100644 impls/bash/step8_macros.sh
 mode change 100755 => 100644 impls/bash/step9_try.sh
 mode change 100755 => 100644 impls/bash/stepA_mal.sh
 mode change 100755 => 100644 impls/basic/step0_repl.in.bas
 mode change 100755 => 100644 impls/basic/step1_read_print.in.bas
 mode change 100755 => 100644 impls/basic/step2_eval.in.bas
 mode change 100755 => 100644 impls/basic/step3_env.in.bas
 mode change 100755 => 100644 impls/basic/step4_if_fn_do.in.bas
 mode change 100755 => 100644 impls/basic/step5_tco.in.bas
 mode change 100755 => 100644 impls/basic/step6_file.in.bas
 mode change 100755 => 100644 impls/basic/step7_quote.in.bas
 mode change 100755 => 100644 impls/basic/step8_macros.in.bas
 mode change 100755 => 100644 impls/basic/step9_try.in.bas
 mode change 100755 => 100644 impls/basic/stepA_mal.in.bas
 mode change 100755 => 100644 impls/crystal/step0_repl.cr
 mode change 100755 => 100644 impls/crystal/step1_read_print.cr
 mode change 100755 => 100644 impls/crystal/step2_eval.cr
 mode change 100755 => 100644 impls/crystal/step3_env.cr
 mode change 100755 => 100644 impls/crystal/step4_if_fn_do.cr
 mode change 100755 => 100644 impls/crystal/step5_tco.cr
 mode change 100755 => 100644 impls/crystal/step6_file.cr
 mode change 100755 => 100644 impls/crystal/step7_quote.cr
 mode change 100755 => 100644 impls/crystal/step8_macros.cr
 mode change 100755 => 100644 impls/crystal/step9_try.cr
 mode change 100755 => 100644 impls/crystal/stepA_mal.cr
 mode change 100755 => 100644 impls/factor/step0_repl/step0_repl.factor
 mode change 100755 => 100644 impls/factor/step1_read_print/step1_read_print.factor
 mode change 100755 => 100644 impls/factor/step2_eval/step2_eval.factor
 mode change 100755 => 100644 impls/factor/step3_env/step3_env.factor
 mode change 100755 => 100644 impls/factor/step4_if_fn_do/step4_if_fn_do.factor
 mode change 100755 => 100644 impls/factor/step5_tco/step5_tco.factor
 mode change 100755 => 100644 impls/factor/step6_file/step6_file.factor
 mode change 100755 => 100644 impls/factor/step7_quote/step7_quote.factor
 mode change 100755 => 100644 impls/factor/step8_macros/step8_macros.factor
 mode change 100755 => 100644 impls/factor/step9_try/step9_try.factor
 mode change 100755 => 100644 impls/factor/stepA_mal/stepA_mal.factor
 mode change 100755 => 100644 impls/hy/step0_repl.hy
 mode change 100755 => 100644 impls/hy/step1_read_print.hy
 mode change 100755 => 100644 impls/hy/step2_eval.hy
 mode change 100755 => 100644 impls/hy/step3_env.hy
 mode change 100755 => 100644 impls/hy/step4_if_fn_do.hy
 mode change 100755 => 100644 impls/hy/step5_tco.hy
 mode change 100755 => 100644 impls/hy/step6_file.hy
 mode change 100755 => 100644 impls/hy/step7_quote.hy
 mode change 100755 => 100644 impls/hy/step8_macros.hy
 mode change 100755 => 100644 impls/hy/step9_try.hy
 mode change 100755 => 100644 impls/hy/stepA_mal.hy
 mode change 100755 => 100644 impls/julia/step0_repl.jl
 mode change 100755 => 100644 impls/julia/step1_read_print.jl
 mode change 100755 => 100644 impls/julia/step2_eval.jl
 mode change 100755 => 100644 impls/julia/step3_env.jl
 mode change 100755 => 100644 impls/julia/step4_if_fn_do.jl
 mode change 100755 => 100644 impls/julia/step5_tco.jl
 mode change 100755 => 100644 impls/julia/step6_file.jl
 mode change 100755 => 100644 impls/julia/step7_quote.jl
 mode change 100755 => 100644 impls/julia/step8_macros.jl
 mode change 100755 => 100644 impls/julia/step9_try.jl
 mode change 100755 => 100644 impls/julia/stepA_mal.jl
 mode change 100755 => 100644 impls/lua/step0_repl.lua
 mode change 100755 => 100644 impls/lua/step1_read_print.lua
 mode change 100755 => 100644 impls/lua/step2_eval.lua
 mode change 100755 => 100644 impls/lua/step3_env.lua
 mode change 100755 => 100644 impls/lua/step4_if_fn_do.lua
 mode change 100755 => 100644 impls/lua/step5_tco.lua
 mode change 100755 => 100644 impls/lua/step6_file.lua
 mode change 100755 => 100644 impls/lua/step7_quote.lua
 mode change 100755 => 100644 impls/lua/step8_macros.lua
 mode change 100755 => 100644 impls/lua/step9_try.lua
 mode change 100755 => 100644 impls/lua/stepA_mal.lua
 mode change 100755 => 100644 impls/make/reader.mk
 mode change 100755 => 100644 impls/plpgsql/init.sql
 mode change 100755 => 100644 impls/racket/step0_repl.rkt
 mode change 100755 => 100644 impls/racket/step1_read_print.rkt
 mode change 100755 => 100644 impls/racket/step2_eval.rkt
 mode change 100755 => 100644 impls/racket/step3_env.rkt
 mode change 100755 => 100644 impls/racket/step4_if_fn_do.rkt
 mode change 100755 => 100644 impls/racket/step5_tco.rkt
 mode change 100755 => 100644 impls/racket/step6_file.rkt
 mode change 100755 => 100644 impls/racket/step7_quote.rkt
 mode change 100755 => 100644 impls/racket/step8_macros.rkt
 mode change 100755 => 100644 impls/racket/step9_try.rkt
 mode change 100755 => 100644 impls/racket/stepA_mal.rkt
 mode change 100755 => 100644 impls/wasm/run.js

diff --git a/examples/clojurewest2014.mal b/examples/clojurewest2014.mal
old mode 100755
new mode 100644
diff --git a/examples/presentation.mal b/examples/presentation.mal
old mode 100755
new mode 100644
diff --git a/impls/ada/Dockerfile b/impls/ada/Dockerfile
old mode 100755
new mode 100644
diff --git a/impls/bash/step0_repl.sh b/impls/bash/step0_repl.sh
old mode 100755
new mode 100644
index 97bce61d17..2d779dd6c8
--- a/impls/bash/step0_repl.sh
+++ b/impls/bash/step0_repl.sh
@@ -1,5 +1,3 @@
-#!/usr/bin/env bash
-
 READ () {
     read -u 0 -e -p "user> " r
 }
diff --git a/impls/bash/step1_read_print.sh b/impls/bash/step1_read_print.sh
old mode 100755
new mode 100644
index 8011fa6b86..b0eba83196
--- a/impls/bash/step1_read_print.sh
+++ b/impls/bash/step1_read_print.sh
@@ -1,5 +1,3 @@
-#!/usr/bin/env bash
-
 source $(dirname $0)/reader.sh
 source $(dirname $0)/printer.sh
 
diff --git a/impls/bash/step2_eval.sh b/impls/bash/step2_eval.sh
old mode 100755
new mode 100644
index 54d75885c3..ad0c15a255
--- a/impls/bash/step2_eval.sh
+++ b/impls/bash/step2_eval.sh
@@ -1,5 +1,3 @@
-#!/usr/bin/env bash
-
 source $(dirname $0)/reader.sh
 source $(dirname $0)/printer.sh
 
diff --git a/impls/bash/step3_env.sh b/impls/bash/step3_env.sh
old mode 100755
new mode 100644
index ba46e54306..f4433c48cb
--- a/impls/bash/step3_env.sh
+++ b/impls/bash/step3_env.sh
@@ -1,5 +1,3 @@
-#!/usr/bin/env bash
-
 source $(dirname $0)/reader.sh
 source $(dirname $0)/printer.sh
 source $(dirname $0)/env.sh
diff --git a/impls/bash/step4_if_fn_do.sh b/impls/bash/step4_if_fn_do.sh
old mode 100755
new mode 100644
index 24b45965fd..129e8959d4
--- a/impls/bash/step4_if_fn_do.sh
+++ b/impls/bash/step4_if_fn_do.sh
@@ -1,5 +1,3 @@
-#!/usr/bin/env bash
-
 source $(dirname $0)/reader.sh
 source $(dirname $0)/printer.sh
 source $(dirname $0)/env.sh
diff --git a/impls/bash/step5_tco.sh b/impls/bash/step5_tco.sh
old mode 100755
new mode 100644
index 5e30751000..c81b1ea2bf
--- a/impls/bash/step5_tco.sh
+++ b/impls/bash/step5_tco.sh
@@ -1,5 +1,3 @@
-#!/usr/bin/env bash
-
 source $(dirname $0)/reader.sh
 source $(dirname $0)/printer.sh
 source $(dirname $0)/env.sh
diff --git a/impls/bash/step6_file.sh b/impls/bash/step6_file.sh
old mode 100755
new mode 100644
index b87cbc1986..e4d0d9c202
--- a/impls/bash/step6_file.sh
+++ b/impls/bash/step6_file.sh
@@ -1,5 +1,3 @@
-#!/usr/bin/env bash
-
 source $(dirname $0)/reader.sh
 source $(dirname $0)/printer.sh
 source $(dirname $0)/env.sh
diff --git a/impls/bash/step7_quote.sh b/impls/bash/step7_quote.sh
old mode 100755
new mode 100644
index dc046f9fc2..0f0183e3b3
--- a/impls/bash/step7_quote.sh
+++ b/impls/bash/step7_quote.sh
@@ -1,5 +1,3 @@
-#!/usr/bin/env bash
-
 source $(dirname $0)/reader.sh
 source $(dirname $0)/printer.sh
 source $(dirname $0)/env.sh
diff --git a/impls/bash/step8_macros.sh b/impls/bash/step8_macros.sh
old mode 100755
new mode 100644
index 64710610e2..d832170e05
--- a/impls/bash/step8_macros.sh
+++ b/impls/bash/step8_macros.sh
@@ -1,5 +1,3 @@
-#!/usr/bin/env bash
-
 source $(dirname $0)/reader.sh
 source $(dirname $0)/printer.sh
 source $(dirname $0)/env.sh
diff --git a/impls/bash/step9_try.sh b/impls/bash/step9_try.sh
old mode 100755
new mode 100644
index bc6336ac34..7749c1b639
--- a/impls/bash/step9_try.sh
+++ b/impls/bash/step9_try.sh
@@ -1,5 +1,3 @@
-#!/usr/bin/env bash
-
 source $(dirname $0)/reader.sh
 source $(dirname $0)/printer.sh
 source $(dirname $0)/env.sh
diff --git a/impls/bash/stepA_mal.sh b/impls/bash/stepA_mal.sh
old mode 100755
new mode 100644
index f65b4b1db2..ba81dffd3c
--- a/impls/bash/stepA_mal.sh
+++ b/impls/bash/stepA_mal.sh
@@ -1,5 +1,3 @@
-#!/usr/bin/env bash
-
 source $(dirname $0)/reader.sh
 source $(dirname $0)/printer.sh
 source $(dirname $0)/env.sh
diff --git a/impls/basic/step0_repl.in.bas b/impls/basic/step0_repl.in.bas
old mode 100755
new mode 100644
diff --git a/impls/basic/step1_read_print.in.bas b/impls/basic/step1_read_print.in.bas
old mode 100755
new mode 100644
diff --git a/impls/basic/step2_eval.in.bas b/impls/basic/step2_eval.in.bas
old mode 100755
new mode 100644
diff --git a/impls/basic/step3_env.in.bas b/impls/basic/step3_env.in.bas
old mode 100755
new mode 100644
diff --git a/impls/basic/step4_if_fn_do.in.bas b/impls/basic/step4_if_fn_do.in.bas
old mode 100755
new mode 100644
diff --git a/impls/basic/step5_tco.in.bas b/impls/basic/step5_tco.in.bas
old mode 100755
new mode 100644
diff --git a/impls/basic/step6_file.in.bas b/impls/basic/step6_file.in.bas
old mode 100755
new mode 100644
diff --git a/impls/basic/step7_quote.in.bas b/impls/basic/step7_quote.in.bas
old mode 100755
new mode 100644
diff --git a/impls/basic/step8_macros.in.bas b/impls/basic/step8_macros.in.bas
old mode 100755
new mode 100644
diff --git a/impls/basic/step9_try.in.bas b/impls/basic/step9_try.in.bas
old mode 100755
new mode 100644
diff --git a/impls/basic/stepA_mal.in.bas b/impls/basic/stepA_mal.in.bas
old mode 100755
new mode 100644
diff --git a/impls/crystal/step0_repl.cr b/impls/crystal/step0_repl.cr
old mode 100755
new mode 100644
index a9c67d68f2..b6a1bfba32
--- a/impls/crystal/step0_repl.cr
+++ b/impls/crystal/step0_repl.cr
@@ -1,5 +1,3 @@
-#! /usr/bin/env crystal run
-
 require "readline"
 
 # Note:
diff --git a/impls/crystal/step1_read_print.cr b/impls/crystal/step1_read_print.cr
old mode 100755
new mode 100644
index 4d7195895e..8c5ddffb9e
--- a/impls/crystal/step1_read_print.cr
+++ b/impls/crystal/step1_read_print.cr
@@ -1,5 +1,3 @@
-#! /usr/bin/env crystal run
-
 require "readline"
 require "./reader"
 require "./printer"
diff --git a/impls/crystal/step2_eval.cr b/impls/crystal/step2_eval.cr
old mode 100755
new mode 100644
index f8713571cd..dd8f2533d1
--- a/impls/crystal/step2_eval.cr
+++ b/impls/crystal/step2_eval.cr
@@ -1,5 +1,3 @@
-#! /usr/bin/env crystal run
-
 require "readline"
 require "./reader"
 require "./printer"
diff --git a/impls/crystal/step3_env.cr b/impls/crystal/step3_env.cr
old mode 100755
new mode 100644
index a17d79779f..fd77be8e46
--- a/impls/crystal/step3_env.cr
+++ b/impls/crystal/step3_env.cr
@@ -1,5 +1,3 @@
-#! /usr/bin/env crystal run
-
 require "readline"
 require "./reader"
 require "./printer"
diff --git a/impls/crystal/step4_if_fn_do.cr b/impls/crystal/step4_if_fn_do.cr
old mode 100755
new mode 100644
index fb33c8911d..251629332d
--- a/impls/crystal/step4_if_fn_do.cr
+++ b/impls/crystal/step4_if_fn_do.cr
@@ -1,5 +1,3 @@
-#! /usr/bin/env crystal run
-
 require "readline"
 require "./reader"
 require "./printer"
diff --git a/impls/crystal/step5_tco.cr b/impls/crystal/step5_tco.cr
old mode 100755
new mode 100644
index 508ed0b176..72a9489606
--- a/impls/crystal/step5_tco.cr
+++ b/impls/crystal/step5_tco.cr
@@ -1,5 +1,3 @@
-#! /usr/bin/env crystal run
-
 require "readline"
 require "./reader"
 require "./printer"
diff --git a/impls/crystal/step6_file.cr b/impls/crystal/step6_file.cr
old mode 100755
new mode 100644
index a7a95e170c..2eff3ba8d0
--- a/impls/crystal/step6_file.cr
+++ b/impls/crystal/step6_file.cr
@@ -1,5 +1,3 @@
-#! /usr/bin/env crystal run
-
 require "readline"
 require "./reader"
 require "./printer"
diff --git a/impls/crystal/step7_quote.cr b/impls/crystal/step7_quote.cr
old mode 100755
new mode 100644
index b935061fa2..0455d143db
--- a/impls/crystal/step7_quote.cr
+++ b/impls/crystal/step7_quote.cr
@@ -1,5 +1,3 @@
-#! /usr/bin/env crystal run
-
 require "readline"
 require "./reader"
 require "./printer"
diff --git a/impls/crystal/step8_macros.cr b/impls/crystal/step8_macros.cr
old mode 100755
new mode 100644
index 2c7ac4e755..57b6063d82
--- a/impls/crystal/step8_macros.cr
+++ b/impls/crystal/step8_macros.cr
@@ -1,5 +1,3 @@
-#! /usr/bin/env crystal run
-
 require "readline"
 require "./reader"
 require "./printer"
diff --git a/impls/crystal/step9_try.cr b/impls/crystal/step9_try.cr
old mode 100755
new mode 100644
index 984158b28f..bfc8a70572
--- a/impls/crystal/step9_try.cr
+++ b/impls/crystal/step9_try.cr
@@ -1,5 +1,3 @@
-#! /usr/bin/env crystal run
-
 require "readline"
 require "./reader"
 require "./printer"
diff --git a/impls/crystal/stepA_mal.cr b/impls/crystal/stepA_mal.cr
old mode 100755
new mode 100644
index 2857c89d13..65fb8e9f8b
--- a/impls/crystal/stepA_mal.cr
+++ b/impls/crystal/stepA_mal.cr
@@ -1,5 +1,3 @@
-#! /usr/bin/env crystal run
-
 require "colorize"
 
 require "readline"
diff --git a/impls/factor/step0_repl/step0_repl.factor b/impls/factor/step0_repl/step0_repl.factor
old mode 100755
new mode 100644
diff --git a/impls/factor/step1_read_print/step1_read_print.factor b/impls/factor/step1_read_print/step1_read_print.factor
old mode 100755
new mode 100644
diff --git a/impls/factor/step2_eval/step2_eval.factor b/impls/factor/step2_eval/step2_eval.factor
old mode 100755
new mode 100644
diff --git a/impls/factor/step3_env/step3_env.factor b/impls/factor/step3_env/step3_env.factor
old mode 100755
new mode 100644
diff --git a/impls/factor/step4_if_fn_do/step4_if_fn_do.factor b/impls/factor/step4_if_fn_do/step4_if_fn_do.factor
old mode 100755
new mode 100644
diff --git a/impls/factor/step5_tco/step5_tco.factor b/impls/factor/step5_tco/step5_tco.factor
old mode 100755
new mode 100644
diff --git a/impls/factor/step6_file/step6_file.factor b/impls/factor/step6_file/step6_file.factor
old mode 100755
new mode 100644
diff --git a/impls/factor/step7_quote/step7_quote.factor b/impls/factor/step7_quote/step7_quote.factor
old mode 100755
new mode 100644
diff --git a/impls/factor/step8_macros/step8_macros.factor b/impls/factor/step8_macros/step8_macros.factor
old mode 100755
new mode 100644
diff --git a/impls/factor/step9_try/step9_try.factor b/impls/factor/step9_try/step9_try.factor
old mode 100755
new mode 100644
diff --git a/impls/factor/stepA_mal/stepA_mal.factor b/impls/factor/stepA_mal/stepA_mal.factor
old mode 100755
new mode 100644
diff --git a/impls/hy/run b/impls/hy/run
index e203849508..7f69c4e5d9 100755
--- a/impls/hy/run
+++ b/impls/hy/run
@@ -1,2 +1,2 @@
 #!/usr/bin/env bash
-exec $(dirname $0)/${STEP:-stepA_mal}.hy "${@}"
+exec hy $(dirname $0)/${STEP:-stepA_mal}.hy "${@}"
diff --git a/impls/hy/step0_repl.hy b/impls/hy/step0_repl.hy
old mode 100755
new mode 100644
index d651bbf0ef..5b837b721b
--- a/impls/hy/step0_repl.hy
+++ b/impls/hy/step0_repl.hy
@@ -1,5 +1,3 @@
-#!/usr/bin/env hy
-
 (defn READ [str]
   str)
 
diff --git a/impls/hy/step1_read_print.hy b/impls/hy/step1_read_print.hy
old mode 100755
new mode 100644
index ba8670e14b..61af6fda01
--- a/impls/hy/step1_read_print.hy
+++ b/impls/hy/step1_read_print.hy
@@ -1,5 +1,3 @@
-#!/usr/bin/env hy
-
 (import sys traceback)
 (import [reader [read-str Blank]])
 (import [printer [pr-str]])
diff --git a/impls/hy/step2_eval.hy b/impls/hy/step2_eval.hy
old mode 100755
new mode 100644
index adfc2a16a6..1ade3ab4dd
--- a/impls/hy/step2_eval.hy
+++ b/impls/hy/step2_eval.hy
@@ -1,5 +1,3 @@
-#!/usr/bin/env hy
-
 (import sys traceback)
 (import [reader [read-str Blank]])
 (import [printer [pr-str]])
diff --git a/impls/hy/step3_env.hy b/impls/hy/step3_env.hy
old mode 100755
new mode 100644
index 26fca8fa7a..1a92f421f7
--- a/impls/hy/step3_env.hy
+++ b/impls/hy/step3_env.hy
@@ -1,5 +1,3 @@
-#!/usr/bin/env hy
-
 (import [hy.models [HySymbol :as Sym]])
 (import sys traceback)
 (import [reader [read-str Blank]])
diff --git a/impls/hy/step4_if_fn_do.hy b/impls/hy/step4_if_fn_do.hy
old mode 100755
new mode 100644
index ae01bf32a5..c65b49c991
--- a/impls/hy/step4_if_fn_do.hy
+++ b/impls/hy/step4_if_fn_do.hy
@@ -1,5 +1,3 @@
-#!/usr/bin/env hy
-
 (import [hy.models [HySymbol :as Sym]])
 (import sys traceback)
 (import [mal_types [MalException]])
diff --git a/impls/hy/step5_tco.hy b/impls/hy/step5_tco.hy
old mode 100755
new mode 100644
index 6b364657ab..6beef1a319
--- a/impls/hy/step5_tco.hy
+++ b/impls/hy/step5_tco.hy
@@ -1,5 +1,3 @@
-#!/usr/bin/env hy
-
 (import [hy.models [HySymbol :as Sym]])
 (import sys traceback)
 (import [mal_types [MalException]])
diff --git a/impls/hy/step6_file.hy b/impls/hy/step6_file.hy
old mode 100755
new mode 100644
index 9cf4c7380a..45f871aff1
--- a/impls/hy/step6_file.hy
+++ b/impls/hy/step6_file.hy
@@ -1,5 +1,3 @@
-#!/usr/bin/env hy
-
 (import [hy.models [HyString :as Str HySymbol :as Sym]])
 (import sys traceback)
 (import [mal_types [MalException]])
diff --git a/impls/hy/step7_quote.hy b/impls/hy/step7_quote.hy
old mode 100755
new mode 100644
index 757852db5f..de7252f2de
--- a/impls/hy/step7_quote.hy
+++ b/impls/hy/step7_quote.hy
@@ -1,5 +1,3 @@
-#!/usr/bin/env hy
-
 (import [hy.models [HyString :as Str HySymbol :as Sym]])
 (import sys traceback)
 (import [mal_types [MalException]])
diff --git a/impls/hy/step8_macros.hy b/impls/hy/step8_macros.hy
old mode 100755
new mode 100644
index 97ee0ee46c..806914b5a6
--- a/impls/hy/step8_macros.hy
+++ b/impls/hy/step8_macros.hy
@@ -1,5 +1,3 @@
-#!/usr/bin/env hy
-
 (import [hy.models [HyString :as Str HySymbol :as Sym]])
 (import sys traceback)
 (import [mal_types [MalException]])
diff --git a/impls/hy/step9_try.hy b/impls/hy/step9_try.hy
old mode 100755
new mode 100644
index 5dc44a0cf0..f852b53fa7
--- a/impls/hy/step9_try.hy
+++ b/impls/hy/step9_try.hy
@@ -1,5 +1,3 @@
-#!/usr/bin/env hy
-
 (import [hy.models [HyString :as Str HySymbol :as Sym]])
 (import sys traceback)
 (import [mal_types [MalException]])
diff --git a/impls/hy/stepA_mal.hy b/impls/hy/stepA_mal.hy
old mode 100755
new mode 100644
index 3e881fdab6..dbffa8835e
--- a/impls/hy/stepA_mal.hy
+++ b/impls/hy/stepA_mal.hy
@@ -1,5 +1,3 @@
-#!/usr/bin/env hy
-
 (import [hy.models [HyString :as Str HySymbol :as Sym]])
 (import sys traceback)
 (import [mal_types [MalException]])
diff --git a/impls/julia/step0_repl.jl b/impls/julia/step0_repl.jl
old mode 100755
new mode 100644
index 049cde1418..e26734a05e
--- a/impls/julia/step0_repl.jl
+++ b/impls/julia/step0_repl.jl
@@ -1,5 +1,3 @@
-#!/usr/bin/env julia
-
 push!(LOAD_PATH, pwd(), "/usr/share/julia/base")
 import readline_mod
 
diff --git a/impls/julia/step1_read_print.jl b/impls/julia/step1_read_print.jl
old mode 100755
new mode 100644
index 604b1f9c3d..9991ebd308
--- a/impls/julia/step1_read_print.jl
+++ b/impls/julia/step1_read_print.jl
@@ -1,5 +1,3 @@
-#!/usr/bin/env julia
-
 push!(LOAD_PATH, pwd(), "/usr/share/julia/base")
 import readline_mod
 import reader
diff --git a/impls/julia/step2_eval.jl b/impls/julia/step2_eval.jl
old mode 100755
new mode 100644
index b64ca9e17c..cc97dbf81e
--- a/impls/julia/step2_eval.jl
+++ b/impls/julia/step2_eval.jl
@@ -1,5 +1,3 @@
-#!/usr/bin/env julia
-
 push!(LOAD_PATH, pwd(), "/usr/share/julia/base")
 import readline_mod
 import reader
diff --git a/impls/julia/step3_env.jl b/impls/julia/step3_env.jl
old mode 100755
new mode 100644
index b1cdd6c595..e4d8a895de
--- a/impls/julia/step3_env.jl
+++ b/impls/julia/step3_env.jl
@@ -1,5 +1,3 @@
-#!/usr/bin/env julia
-
 push!(LOAD_PATH, pwd(), "/usr/share/julia/base")
 import readline_mod
 import reader
diff --git a/impls/julia/step4_if_fn_do.jl b/impls/julia/step4_if_fn_do.jl
old mode 100755
new mode 100644
index 70334f4337..ffb421eba0
--- a/impls/julia/step4_if_fn_do.jl
+++ b/impls/julia/step4_if_fn_do.jl
@@ -1,5 +1,3 @@
-#!/usr/bin/env julia
-
 push!(LOAD_PATH, pwd(), "/usr/share/julia/base")
 import readline_mod
 import reader
diff --git a/impls/julia/step5_tco.jl b/impls/julia/step5_tco.jl
old mode 100755
new mode 100644
index 08ed0659cf..9741829cef
--- a/impls/julia/step5_tco.jl
+++ b/impls/julia/step5_tco.jl
@@ -1,5 +1,3 @@
-#!/usr/bin/env julia
-
 push!(LOAD_PATH, pwd(), "/usr/share/julia/base")
 import readline_mod
 import reader
diff --git a/impls/julia/step6_file.jl b/impls/julia/step6_file.jl
old mode 100755
new mode 100644
index 0c39d0516e..3654228609
--- a/impls/julia/step6_file.jl
+++ b/impls/julia/step6_file.jl
@@ -1,5 +1,3 @@
-#!/usr/bin/env julia
-
 push!(LOAD_PATH, pwd(), "/usr/share/julia/base")
 import readline_mod
 import reader
diff --git a/impls/julia/step7_quote.jl b/impls/julia/step7_quote.jl
old mode 100755
new mode 100644
index 86148cfd67..66b43232d5
--- a/impls/julia/step7_quote.jl
+++ b/impls/julia/step7_quote.jl
@@ -1,5 +1,3 @@
-#!/usr/bin/env julia
-
 push!(LOAD_PATH, pwd(), "/usr/share/julia/base")
 import readline_mod
 import reader
diff --git a/impls/julia/step8_macros.jl b/impls/julia/step8_macros.jl
old mode 100755
new mode 100644
index 5dee5a32e1..ef460889bd
--- a/impls/julia/step8_macros.jl
+++ b/impls/julia/step8_macros.jl
@@ -1,5 +1,3 @@
-#!/usr/bin/env julia
-
 push!(LOAD_PATH, pwd(), "/usr/share/julia/base")
 import readline_mod
 import reader
diff --git a/impls/julia/step9_try.jl b/impls/julia/step9_try.jl
old mode 100755
new mode 100644
index 73c18d01df..ca902b98a1
--- a/impls/julia/step9_try.jl
+++ b/impls/julia/step9_try.jl
@@ -1,5 +1,3 @@
-#!/usr/bin/env julia
-
 push!(LOAD_PATH, pwd(), "/usr/share/julia/base")
 import readline_mod
 import reader
diff --git a/impls/julia/stepA_mal.jl b/impls/julia/stepA_mal.jl
old mode 100755
new mode 100644
index efeabef3e6..6f71851eed
--- a/impls/julia/stepA_mal.jl
+++ b/impls/julia/stepA_mal.jl
@@ -1,5 +1,3 @@
-#!/usr/bin/env julia
-
 push!(LOAD_PATH, pwd(), "/usr/share/julia/base")
 import readline_mod
 import reader
diff --git a/impls/lua/step0_repl.lua b/impls/lua/step0_repl.lua
old mode 100755
new mode 100644
index bb082a599d..94290842f8
--- a/impls/lua/step0_repl.lua
+++ b/impls/lua/step0_repl.lua
@@ -1,5 +1,3 @@
-#!/usr/bin/env lua
-
 local readline = require('readline')
 
 function READ(str)
diff --git a/impls/lua/step1_read_print.lua b/impls/lua/step1_read_print.lua
old mode 100755
new mode 100644
index 78cde8c1fe..db7ec5d2dd
--- a/impls/lua/step1_read_print.lua
+++ b/impls/lua/step1_read_print.lua
@@ -1,5 +1,3 @@
-#!/usr/bin/env lua
-
 local readline = require('readline')
 local types = require('types')
 local reader = require('reader')
diff --git a/impls/lua/step2_eval.lua b/impls/lua/step2_eval.lua
old mode 100755
new mode 100644
index 0bb44d2a26..3259c87ca1
--- a/impls/lua/step2_eval.lua
+++ b/impls/lua/step2_eval.lua
@@ -1,5 +1,3 @@
-#!/usr/bin/env lua
-
 local table = require('table')
 
 local readline = require('readline')
diff --git a/impls/lua/step3_env.lua b/impls/lua/step3_env.lua
old mode 100755
new mode 100644
index 297083deed..93afe5d885
--- a/impls/lua/step3_env.lua
+++ b/impls/lua/step3_env.lua
@@ -1,5 +1,3 @@
-#!/usr/bin/env lua
-
 local table = require('table')
 
 local readline = require('readline')
diff --git a/impls/lua/step4_if_fn_do.lua b/impls/lua/step4_if_fn_do.lua
old mode 100755
new mode 100644
index f69c2379ed..d89653c391
--- a/impls/lua/step4_if_fn_do.lua
+++ b/impls/lua/step4_if_fn_do.lua
@@ -1,5 +1,3 @@
-#!/usr/bin/env lua
-
 local table = require('table')
 
 local readline = require('readline')
diff --git a/impls/lua/step5_tco.lua b/impls/lua/step5_tco.lua
old mode 100755
new mode 100644
index 923a148357..d985db589a
--- a/impls/lua/step5_tco.lua
+++ b/impls/lua/step5_tco.lua
@@ -1,5 +1,3 @@
-#!/usr/bin/env lua
-
 local table = require('table')
 
 local readline = require('readline')
diff --git a/impls/lua/step6_file.lua b/impls/lua/step6_file.lua
old mode 100755
new mode 100644
index 2f5abf7d57..2d8a952734
--- a/impls/lua/step6_file.lua
+++ b/impls/lua/step6_file.lua
@@ -1,5 +1,3 @@
-#!/usr/bin/env lua
-
 local table = require('table')
 
 local readline = require('readline')
diff --git a/impls/lua/step7_quote.lua b/impls/lua/step7_quote.lua
old mode 100755
new mode 100644
index 67de77665f..0a334d58d0
--- a/impls/lua/step7_quote.lua
+++ b/impls/lua/step7_quote.lua
@@ -1,5 +1,3 @@
-#!/usr/bin/env lua
-
 local table = require('table')
 
 local readline = require('readline')
diff --git a/impls/lua/step8_macros.lua b/impls/lua/step8_macros.lua
old mode 100755
new mode 100644
index ce12dc864e..b33ffb8f88
--- a/impls/lua/step8_macros.lua
+++ b/impls/lua/step8_macros.lua
@@ -1,5 +1,3 @@
-#!/usr/bin/env lua
-
 local table = require('table')
 
 local readline = require('readline')
diff --git a/impls/lua/step9_try.lua b/impls/lua/step9_try.lua
old mode 100755
new mode 100644
index a6fe507d5f..2634ac953a
--- a/impls/lua/step9_try.lua
+++ b/impls/lua/step9_try.lua
@@ -1,5 +1,3 @@
-#!/usr/bin/env lua
-
 local table = require('table')
 
 local readline = require('readline')
diff --git a/impls/lua/stepA_mal.lua b/impls/lua/stepA_mal.lua
old mode 100755
new mode 100644
index 242b1cdda4..76f614966e
--- a/impls/lua/stepA_mal.lua
+++ b/impls/lua/stepA_mal.lua
@@ -1,5 +1,3 @@
-#!/usr/bin/env lua
-
 local table = require('table')
 
 package.path = '../lua/?.lua;' .. package.path
diff --git a/impls/make/reader.mk b/impls/make/reader.mk
old mode 100755
new mode 100644
diff --git a/impls/perl/step0_repl.pl b/impls/perl/step0_repl.pl
index 2947178df3..6d062f9995 100644
--- a/impls/perl/step0_repl.pl
+++ b/impls/perl/step0_repl.pl
@@ -1,5 +1,3 @@
-#!/usr/bin/perl
-
 use strict;
 use warnings;
 use File::Basename 'dirname';
diff --git a/impls/perl/step1_read_print.pl b/impls/perl/step1_read_print.pl
index 43f2d82fcf..4795044404 100644
--- a/impls/perl/step1_read_print.pl
+++ b/impls/perl/step1_read_print.pl
@@ -1,5 +1,3 @@
-#!/usr/bin/perl
-
 use strict;
 use warnings;
 use File::Basename 'dirname';
diff --git a/impls/perl/step2_eval.pl b/impls/perl/step2_eval.pl
index 23bccdc69f..648f40e2af 100644
--- a/impls/perl/step2_eval.pl
+++ b/impls/perl/step2_eval.pl
@@ -1,5 +1,3 @@
-#!/usr/bin/perl
-
 use strict;
 use warnings;
 use File::Basename 'dirname';
diff --git a/impls/perl/step3_env.pl b/impls/perl/step3_env.pl
index 9b09031d8a..02e87ac0e3 100644
--- a/impls/perl/step3_env.pl
+++ b/impls/perl/step3_env.pl
@@ -1,5 +1,3 @@
-#!/usr/bin/perl
-
 use strict;
 use warnings;
 use File::Basename 'dirname';
diff --git a/impls/perl/step4_if_fn_do.pl b/impls/perl/step4_if_fn_do.pl
index df4b825302..8b165fcd5f 100644
--- a/impls/perl/step4_if_fn_do.pl
+++ b/impls/perl/step4_if_fn_do.pl
@@ -1,5 +1,3 @@
-#!/usr/bin/perl
-
 use strict;
 use warnings;
 use File::Basename 'dirname';
diff --git a/impls/perl/step5_tco.pl b/impls/perl/step5_tco.pl
index 7d2460de36..6f4f04e998 100644
--- a/impls/perl/step5_tco.pl
+++ b/impls/perl/step5_tco.pl
@@ -1,5 +1,3 @@
-#!/usr/bin/perl
-
 use strict;
 use warnings FATAL => 'recursion';
 use File::Basename 'dirname';
diff --git a/impls/perl/step6_file.pl b/impls/perl/step6_file.pl
index e0eca83ec5..9c677cc585 100644
--- a/impls/perl/step6_file.pl
+++ b/impls/perl/step6_file.pl
@@ -1,5 +1,3 @@
-#!/usr/bin/perl
-
 use strict;
 use warnings FATAL => 'recursion';
 use File::Basename 'dirname';
diff --git a/impls/perl/step7_quote.pl b/impls/perl/step7_quote.pl
index ceee9c894f..0891ae9886 100644
--- a/impls/perl/step7_quote.pl
+++ b/impls/perl/step7_quote.pl
@@ -1,5 +1,3 @@
-#!/usr/bin/perl
-
 use strict;
 use warnings FATAL => 'recursion';
 use File::Basename 'dirname';
diff --git a/impls/perl/step8_macros.pl b/impls/perl/step8_macros.pl
index aee1bb8274..bd9b3a888c 100644
--- a/impls/perl/step8_macros.pl
+++ b/impls/perl/step8_macros.pl
@@ -1,5 +1,3 @@
-#!/usr/bin/perl
-
 use strict;
 use warnings FATAL => 'recursion';
 use File::Basename 'dirname';
diff --git a/impls/perl/step9_try.pl b/impls/perl/step9_try.pl
index 3612fba99d..73bddfd2ed 100644
--- a/impls/perl/step9_try.pl
+++ b/impls/perl/step9_try.pl
@@ -1,5 +1,3 @@
-#!/usr/bin/perl
-
 use strict;
 use warnings FATAL => 'recursion';
 use File::Basename 'dirname';
diff --git a/impls/perl/stepA_mal.pl b/impls/perl/stepA_mal.pl
index e48046d504..609df2613a 100644
--- a/impls/perl/stepA_mal.pl
+++ b/impls/perl/stepA_mal.pl
@@ -1,5 +1,3 @@
-#!/usr/bin/perl
-
 use strict;
 use warnings FATAL => 'recursion';
 use File::Basename 'dirname';
diff --git a/impls/plpgsql/init.sql b/impls/plpgsql/init.sql
old mode 100755
new mode 100644
diff --git a/impls/racket/step0_repl.rkt b/impls/racket/step0_repl.rkt
old mode 100755
new mode 100644
index 643d132fa2..8cd3913fa9
--- a/impls/racket/step0_repl.rkt
+++ b/impls/racket/step0_repl.rkt
@@ -1,4 +1,3 @@
-#!/usr/bin/env racket
 #lang racket
 
 (require "readline.rkt" "types.rkt")
diff --git a/impls/racket/step1_read_print.rkt b/impls/racket/step1_read_print.rkt
old mode 100755
new mode 100644
index a5d8ac7761..53a64b4382
--- a/impls/racket/step1_read_print.rkt
+++ b/impls/racket/step1_read_print.rkt
@@ -1,4 +1,3 @@
-#!/usr/bin/env racket
 #lang racket
 
 (require "readline.rkt" "types.rkt" "reader.rkt" "printer.rkt")
diff --git a/impls/racket/step2_eval.rkt b/impls/racket/step2_eval.rkt
old mode 100755
new mode 100644
index 7ea1ce8f5d..08ac5a2ee6
--- a/impls/racket/step2_eval.rkt
+++ b/impls/racket/step2_eval.rkt
@@ -1,4 +1,3 @@
-#!/usr/bin/env racket
 #lang racket
 
 (require "types.rkt" "readline.rkt" "reader.rkt" "printer.rkt")
diff --git a/impls/racket/step3_env.rkt b/impls/racket/step3_env.rkt
old mode 100755
new mode 100644
index 8ecd818507..469e07fb8f
--- a/impls/racket/step3_env.rkt
+++ b/impls/racket/step3_env.rkt
@@ -1,4 +1,3 @@
-#!/usr/bin/env racket
 #lang racket
 
 (require "readline.rkt" "types.rkt" "reader.rkt" "printer.rkt"
diff --git a/impls/racket/step4_if_fn_do.rkt b/impls/racket/step4_if_fn_do.rkt
old mode 100755
new mode 100644
index 44af35c119..28a46b18e2
--- a/impls/racket/step4_if_fn_do.rkt
+++ b/impls/racket/step4_if_fn_do.rkt
@@ -1,4 +1,3 @@
-#!/usr/bin/env racket
 #lang racket
 
 (require "readline.rkt" "types.rkt" "reader.rkt" "printer.rkt"
diff --git a/impls/racket/step5_tco.rkt b/impls/racket/step5_tco.rkt
old mode 100755
new mode 100644
index 880e05ae5c..2d2f3defaf
--- a/impls/racket/step5_tco.rkt
+++ b/impls/racket/step5_tco.rkt
@@ -1,4 +1,3 @@
-#!/usr/bin/env racket
 #lang racket
 
 (require "readline.rkt" "types.rkt" "reader.rkt" "printer.rkt"
diff --git a/impls/racket/step6_file.rkt b/impls/racket/step6_file.rkt
old mode 100755
new mode 100644
index 6e1645bce9..783978ed61
--- a/impls/racket/step6_file.rkt
+++ b/impls/racket/step6_file.rkt
@@ -1,4 +1,3 @@
-#!/usr/bin/env racket
 #lang racket
 
 (require "readline.rkt" "types.rkt" "reader.rkt" "printer.rkt"
diff --git a/impls/racket/step7_quote.rkt b/impls/racket/step7_quote.rkt
old mode 100755
new mode 100644
index d9257f4889..f61aa7d000
--- a/impls/racket/step7_quote.rkt
+++ b/impls/racket/step7_quote.rkt
@@ -1,4 +1,3 @@
-#!/usr/bin/env racket
 #lang racket
 
 (require "readline.rkt" "types.rkt" "reader.rkt" "printer.rkt"
diff --git a/impls/racket/step8_macros.rkt b/impls/racket/step8_macros.rkt
old mode 100755
new mode 100644
index 864093047e..88a6d36567
--- a/impls/racket/step8_macros.rkt
+++ b/impls/racket/step8_macros.rkt
@@ -1,4 +1,3 @@
-#!/usr/bin/env racket
 #lang racket
 
 (require "readline.rkt" "types.rkt" "reader.rkt" "printer.rkt"
diff --git a/impls/racket/step9_try.rkt b/impls/racket/step9_try.rkt
old mode 100755
new mode 100644
index c8534d3b2b..ad42d983dc
--- a/impls/racket/step9_try.rkt
+++ b/impls/racket/step9_try.rkt
@@ -1,4 +1,3 @@
-#!/usr/bin/env racket
 #lang racket
 
 (require "readline.rkt" "types.rkt" "reader.rkt" "printer.rkt"
diff --git a/impls/racket/stepA_mal.rkt b/impls/racket/stepA_mal.rkt
old mode 100755
new mode 100644
index c94bb80137..83cb4d13aa
--- a/impls/racket/stepA_mal.rkt
+++ b/impls/racket/stepA_mal.rkt
@@ -1,4 +1,3 @@
-#!/usr/bin/env racket
 #lang racket
 
 (require "readline.rkt" "types.rkt" "reader.rkt" "printer.rkt"
diff --git a/impls/wasm/run b/impls/wasm/run
index 7d4fed5185..29c44131c2 100755
--- a/impls/wasm/run
+++ b/impls/wasm/run
@@ -14,5 +14,5 @@ wace_libc)
 wace_fooboot)
     echo >&2 "wace_fooboot mode not yet supported" ;;
 node|js|*)
-    exec ./run.js $(dirname $0)/${STEP:-stepA_mal}.wasm "${@}" ;;
+    exec node run.js $(dirname $0)/${STEP:-stepA_mal}.wasm "${@}" ;;
 esac
diff --git a/impls/wasm/run.js b/impls/wasm/run.js
old mode 100755
new mode 100644
index 2deaa5e53c..59a705583d
--- a/impls/wasm/run.js
+++ b/impls/wasm/run.js
@@ -1,5 +1,3 @@
-#!/usr/bin/env node
-
 // Copyright Joel Martin
 // License MIT
 
@@ -128,7 +126,7 @@ async function loadWebAssembly(filename, args) {
 
 async function main() {
   assert(process.argv.length >= 3,
-         'Usage: ./run.js prog.wasm [ARGS...]')
+         'Usage: node run.js prog.wasm [ARGS...]')
 
   const wasm = process.argv[2]
   const args = process.argv.slice(2)

From 41fd2267c7fec81cfbd490c32286bad33373be31 Mon Sep 17 00:00:00 2001
From: Nicolas Boulenguez <nicolas.boulenguez@free.fr>
Date: Thu, 16 Apr 2026 19:29:23 +0200
Subject: [PATCH 04/10] Merge some run scripts [1/2]

This change is split so that git shows meaningful diffs.
---
 impls/plpgsql/run   | 2 --
 impls/plsql/run     | 2 --
 impls/vhdl/run      | 2 --
 impls/vimscript/run | 3 ---
 4 files changed, 9 deletions(-)
 delete mode 100755 impls/plpgsql/run
 delete mode 100755 impls/plsql/run
 delete mode 100755 impls/vhdl/run
 delete mode 100755 impls/vimscript/run

diff --git a/impls/plpgsql/run b/impls/plpgsql/run
deleted file mode 100755
index a16184e01a..0000000000
--- a/impls/plpgsql/run
+++ /dev/null
@@ -1,2 +0,0 @@
-#!/usr/bin/env bash
-exec $(dirname $0)/wrap.sh $(dirname $0)/${STEP:-stepA_mal}.sql "${@}"
diff --git a/impls/plsql/run b/impls/plsql/run
deleted file mode 100755
index a16184e01a..0000000000
--- a/impls/plsql/run
+++ /dev/null
@@ -1,2 +0,0 @@
-#!/usr/bin/env bash
-exec $(dirname $0)/wrap.sh $(dirname $0)/${STEP:-stepA_mal}.sql "${@}"
diff --git a/impls/vhdl/run b/impls/vhdl/run
deleted file mode 100755
index ca50d3f82b..0000000000
--- a/impls/vhdl/run
+++ /dev/null
@@ -1,2 +0,0 @@
-#!/usr/bin/env bash
-exec $(dirname $0)/run_vhdl.sh $(dirname $0)/${STEP:-stepA_mal} "${@}"
diff --git a/impls/vimscript/run b/impls/vimscript/run
deleted file mode 100755
index 007df20bdf..0000000000
--- a/impls/vimscript/run
+++ /dev/null
@@ -1,3 +0,0 @@
-#!/usr/bin/env bash
-cd $(dirname $0)
-exec ./run_vimscript.sh ./${STEP:-stepA_mal}.vim "${@}"

From a657d3df176da15d842475732842bfec778ac479 Mon Sep 17 00:00:00 2001
From: Nicolas Boulenguez <nicolas.boulenguez@free.fr>
Date: Sat, 18 Apr 2026 19:30:43 +0200
Subject: [PATCH 05/10] Merge some run scripts [2/2]

---
 impls/plpgsql/{wrap.sh => run}            | 6 +++---
 impls/plsql/{wrap.sh => run}              | 4 ++--
 impls/vhdl/{run_vhdl.sh => run}           | 5 ++---
 impls/vimscript/{run_vimscript.sh => run} | 3 +--
 4 files changed, 8 insertions(+), 10 deletions(-)
 rename impls/plpgsql/{wrap.sh => run} (94%)
 rename impls/plsql/{wrap.sh => run} (98%)
 rename impls/vhdl/{run_vhdl.sh => run} (86%)
 rename impls/vimscript/{run_vimscript.sh => run} (90%)

diff --git a/impls/plpgsql/wrap.sh b/impls/plpgsql/run
similarity index 94%
rename from impls/plpgsql/wrap.sh
rename to impls/plpgsql/run
index e14c072d6a..b4237611be 100755
--- a/impls/plpgsql/wrap.sh
+++ b/impls/plpgsql/run
@@ -1,4 +1,5 @@
 #!/usr/bin/env bash
+step=${STEP:-stepA_mal}.sql
 
 RL_HISTORY_FILE=${HOME}/.mal-history
 SKIP_INIT="${SKIP_INIT:-}"
@@ -25,8 +26,8 @@ cleanup () {
 trap "cleanup" TERM QUIT INT EXIT
 ${PSQL} -tc "SELECT 1 FROM pg_database WHERE datname = 'mal'" \
     | grep -q 1 || ${PSQL} -c "CREATE DATABASE mal"
-#[ "${SKIP_INIT}" ] || ${PSQL} -dmal -f $1 > /dev/null
-[ "${SKIP_INIT}" ] || ${PSQL} -dmal -f $1
+#[ "${SKIP_INIT}" ] || ${PSQL} -dmal -f $step > /dev/null
+[ "${SKIP_INIT}" ] || ${PSQL} -dmal -f $step
 
 ${PSQL} -dmal -c "SELECT io.open(0); SELECT io.open(1);" > /dev/null
 
@@ -59,7 +60,6 @@ ${PSQL} -dmal -c "SELECT io.close(0);" > /dev/null
 STDIN_PID=$!
 
 res=0
-shift
 if [ $# -gt 0 ]; then
     # If there are command line arguments then run a command and exit
     args=$(for a in "$@"; do echo -n "\"$a\" "; done)
diff --git a/impls/plsql/wrap.sh b/impls/plsql/run
similarity index 98%
rename from impls/plsql/wrap.sh
rename to impls/plsql/run
index c106ecb98b..39f9d037c1 100755
--- a/impls/plsql/wrap.sh
+++ b/impls/plsql/run
@@ -1,4 +1,5 @@
 #!/usr/bin/env bash
+step=${STEP:-stepA_mal}.sql
 
 RL_HISTORY_FILE=${HOME}/.mal-history
 SKIP_INIT="${SKIP_INIT:-}"
@@ -17,7 +18,7 @@ trap "cleanup" TERM QUIT INT EXIT
 
 # Load the SQL code
 if [ -z "${SKIP_INIT}" ]; then
-    out=$(echo "" | ${SQLPLUS} @$1)
+    out=$(echo "" | ${SQLPLUS} @$step)
     if echo "${out}" | grep -vs "^No errors.$" \
         | grep -si error >/dev/null; then
     #if echo "${out}"  | grep -si error >/dev/null; then
@@ -104,7 +105,6 @@ done
 FILE_PID=$!
 
 res=0
-shift
 if [ $# -gt 0 ]; then
     # If there are command line arguments then run a command and exit
     args=$(for a in "$@"; do echo -n "\"$a\" "; done)
diff --git a/impls/vhdl/run_vhdl.sh b/impls/vhdl/run
similarity index 86%
rename from impls/vhdl/run_vhdl.sh
rename to impls/vhdl/run
index 14fbd35131..0d3a5d40c4 100755
--- a/impls/vhdl/run_vhdl.sh
+++ b/impls/vhdl/run
@@ -5,11 +5,10 @@
 # vhdl_argv.tmp, and read the content of that file at the beginning of the VHDL
 # program.
 
-bin="$1"
-shift
+bin="$(dirname $0)/${STEP:-stepA_mal}"
 
 for arg in "$@" ; do
     echo "$arg"
 done > vhdl_argv.tmp
 
-$bin
+exec $bin
diff --git a/impls/vimscript/run_vimscript.sh b/impls/vimscript/run
similarity index 90%
rename from impls/vimscript/run_vimscript.sh
rename to impls/vimscript/run
index cf263c8f7f..6a98e91302 100755
--- a/impls/vimscript/run_vimscript.sh
+++ b/impls/vimscript/run
@@ -9,8 +9,7 @@
 
 rundir=`dirname $0`
 export LD_LIBRARY_PATH=`readlink -f $rundir`
-vimscriptfile="$1"
-shift
+vimscriptfile="$(dirname $0)/${STEP:-stepA_mal}.vim"
 if [ x$DEBUG = x ] ; then
   exec 2> /dev/null
 fi

From 5b94c4592363d3b62199c6d0ca4427b4760da714 Mon Sep 17 00:00:00 2001
From: Nicolas Boulenguez <nicolas.boulenguez@free.fr>
Date: Sun, 19 Apr 2026 14:48:25 +0200
Subject: [PATCH 06/10] scheme: in run script, compute paths portably and on
 demand

https://unix.stackexchange.com/questions/85249/why-not-use-which-what-to-use-then
---
 impls/scheme/run | 32 ++++++++++++++++++--------------
 1 file changed, 18 insertions(+), 14 deletions(-)

diff --git a/impls/scheme/run b/impls/scheme/run
index 8cfd055ae2..acef8c0753 100755
--- a/impls/scheme/run
+++ b/impls/scheme/run
@@ -2,24 +2,28 @@
 basedir=$(dirname $0)
 step=${STEP:-stepA_mal}
 
-if [[ -e /usr/share/kawa/lib/kawa.jar ]]; then
-    kawa=/usr/share/kawa/lib/kawa.jar
-elif [[ -e /usr/local/share/kawa/lib/kawa.jar ]]; then
-    kawa=/usr/local/share/kawa/lib/kawa.jar
-fi
-
-if [[ $(which sash 2>/dev/null) ]]; then
-    sagittarius=sash
-elif [[ $(which sagittarius 2>/dev/null) ]]; then
-    sagittarius=sagittarius
-fi
-
 case ${scheme_MODE:-chibi} in
     chibi)       exec chibi-scheme -I$basedir $basedir/$step.scm      "${@}" ;;
-    kawa)        exec java -cp $kawa:$basedir/out $step               "${@}" ;;
+    kawa)        if [ -e /usr/share/kawa/lib/kawa.jar ]; then
+                     kawa=/usr/share/kawa/lib/kawa.jar
+                  elif [ -e /usr/local/share/kawa/lib/kawa.jar ]; then
+                     kawa=/usr/local/share/kawa/lib/kawa.jar
+                 else
+                     echo >&2 'Failed to find kawa.jar.'
+                     exit 1
+                 fi
+                 exec java -cp $kawa:$basedir/out $step               "${@}" ;;
     gauche)      exec gosh -I$basedir $basedir/$step.scm              "${@}" ;;
     chicken)     CHICKEN_REPOSITORY=$basedir/eggs exec $basedir/$step "${@}" ;;
-    sagittarius) exec $sagittarius -n -L$basedir $basedir/$step.scm   "${@}" ;;
+    sagittarius) if command -v sash >/dev/null 2>&1; then
+                     sagittarius=sash
+                 elif command -v sagittarius >/dev/null 2>&1; then
+                     sagittarius=sagittarius
+                 else
+                     echo >&2 'Failed to find sash or sagittarius.'
+                     exit 1
+                 fi
+                 exec $sagittarius -n -L$basedir $basedir/$step.scm   "${@}" ;;
     cyclone)     exec $basedir/$step                                  "${@}" ;;
     foment)      exec foment $basedir/$step.scm                       "${@}" ;;
     *) echo "Invalid scheme_MODE: ${scheme_MODE}"; exit 2 ;;

From 47c4d23d5a03f212b12eff7d60dd26cf2b13d2fe Mon Sep 17 00:00:00 2001
From: Nicolas Boulenguez <nicolas.boulenguez@free.fr>
Date: Mon, 20 Apr 2026 00:36:03 +0200
Subject: [PATCH 07/10] perl: (style) silent a warning about comparing an
 undefined value

---
 impls/perl/step0_repl.pl       | 2 +-
 impls/perl/step1_read_print.pl | 2 +-
 impls/perl/step2_eval.pl       | 2 +-
 impls/perl/step3_env.pl        | 2 +-
 impls/perl/step4_if_fn_do.pl   | 2 +-
 impls/perl/step5_tco.pl        | 2 +-
 impls/perl/step6_file.pl       | 2 +-
 impls/perl/step7_quote.pl      | 2 +-
 impls/perl/step8_macros.pl     | 2 +-
 impls/perl/step9_try.pl        | 2 +-
 impls/perl/stepA_mal.pl        | 2 +-
 11 files changed, 11 insertions(+), 11 deletions(-)

diff --git a/impls/perl/step0_repl.pl b/impls/perl/step0_repl.pl
index 6d062f9995..a0018328a5 100644
--- a/impls/perl/step0_repl.pl
+++ b/impls/perl/step0_repl.pl
@@ -32,7 +32,7 @@ sub REP {
 }
 
 # Command line arguments
-if ( $ARGV[0] eq '--raw' ) {
+if ( @ARGV and  $ARGV[0] eq '--raw' ) {
     set_rl_mode('raw');
     shift @ARGV;
 }
diff --git a/impls/perl/step1_read_print.pl b/impls/perl/step1_read_print.pl
index 4795044404..36f1bd92e9 100644
--- a/impls/perl/step1_read_print.pl
+++ b/impls/perl/step1_read_print.pl
@@ -34,7 +34,7 @@ sub REP {
 }
 
 # Command line arguments
-if ( $ARGV[0] eq '--raw' ) {
+if ( @ARGV and  $ARGV[0] eq '--raw' ) {
     set_rl_mode('raw');
     shift @ARGV;
 }
diff --git a/impls/perl/step2_eval.pl b/impls/perl/step2_eval.pl
index 648f40e2af..6ed7b5b3c7 100644
--- a/impls/perl/step2_eval.pl
+++ b/impls/perl/step2_eval.pl
@@ -61,7 +61,7 @@ sub REP {
 }
 
 # Command line arguments
-if ( $ARGV[0] eq '--raw' ) {
+if ( @ARGV and  $ARGV[0] eq '--raw' ) {
     set_rl_mode('raw');
     shift @ARGV;
 }
diff --git a/impls/perl/step3_env.pl b/impls/perl/step3_env.pl
index 02e87ac0e3..8add028df0 100644
--- a/impls/perl/step3_env.pl
+++ b/impls/perl/step3_env.pl
@@ -91,7 +91,7 @@ sub REP {
 }
 
 # Command line arguments
-if ( $ARGV[0] eq '--raw' ) {
+if ( @ARGV and  $ARGV[0] eq '--raw' ) {
     set_rl_mode('raw');
     shift @ARGV;
 }
diff --git a/impls/perl/step4_if_fn_do.pl b/impls/perl/step4_if_fn_do.pl
index 8b165fcd5f..b4cc282aca 100644
--- a/impls/perl/step4_if_fn_do.pl
+++ b/impls/perl/step4_if_fn_do.pl
@@ -122,7 +122,7 @@ sub REP {
 }
 
 # Command line arguments
-if ( $ARGV[0] eq '--raw' ) {
+if ( @ARGV and $ARGV[0] eq '--raw' ) {
     set_rl_mode('raw');
     shift @ARGV;
 }
diff --git a/impls/perl/step5_tco.pl b/impls/perl/step5_tco.pl
index 6f4f04e998..de59963b0b 100644
--- a/impls/perl/step5_tco.pl
+++ b/impls/perl/step5_tco.pl
@@ -132,7 +132,7 @@ sub REP {
 }
 
 # Command line arguments
-if ( $ARGV[0] eq '--raw' ) {
+if ( @ARGV and $ARGV[0] eq '--raw' ) {
     set_rl_mode('raw');
     shift @ARGV;
 }
diff --git a/impls/perl/step6_file.pl b/impls/perl/step6_file.pl
index 9c677cc585..ce6c496fc0 100644
--- a/impls/perl/step6_file.pl
+++ b/impls/perl/step6_file.pl
@@ -132,7 +132,7 @@ sub REP {
 }
 
 # Command line arguments
-if ( $ARGV[0] eq '--raw' ) {
+if ( @ARGV and $ARGV[0] eq '--raw' ) {
     set_rl_mode('raw');
     shift @ARGV;
 }
diff --git a/impls/perl/step7_quote.pl b/impls/perl/step7_quote.pl
index 0891ae9886..6042b83535 100644
--- a/impls/perl/step7_quote.pl
+++ b/impls/perl/step7_quote.pl
@@ -185,7 +185,7 @@ sub REP {
 }
 
 # Command line arguments
-if ( $ARGV[0] eq '--raw' ) {
+if ( @ARGV and $ARGV[0] eq '--raw' ) {
     set_rl_mode('raw');
     shift @ARGV;
 }
diff --git a/impls/perl/step8_macros.pl b/impls/perl/step8_macros.pl
index bd9b3a888c..75c040a2f8 100644
--- a/impls/perl/step8_macros.pl
+++ b/impls/perl/step8_macros.pl
@@ -196,7 +196,7 @@ sub REP {
 }
 
 # Command line arguments
-if ( $ARGV[0] eq '--raw' ) {
+if ( @ARGV and $ARGV[0] eq '--raw' ) {
     set_rl_mode('raw');
     shift @ARGV;
 }
diff --git a/impls/perl/step9_try.pl b/impls/perl/step9_try.pl
index 73bddfd2ed..c3311d1ed6 100644
--- a/impls/perl/step9_try.pl
+++ b/impls/perl/step9_try.pl
@@ -219,7 +219,7 @@ sub REP {
 }
 
 # Command line arguments
-if ( $ARGV[0] eq '--raw' ) {
+if ( @ARGV and $ARGV[0] eq '--raw' ) {
     set_rl_mode('raw');
     shift @ARGV;
 }
diff --git a/impls/perl/stepA_mal.pl b/impls/perl/stepA_mal.pl
index 609df2613a..698f9fb148 100644
--- a/impls/perl/stepA_mal.pl
+++ b/impls/perl/stepA_mal.pl
@@ -219,7 +219,7 @@ sub REP {
 }
 
 # Command line arguments
-if ( $ARGV[0] eq '--raw' ) {
+if ( @ARGV and $ARGV[0] eq '--raw' ) {
     set_rl_mode('raw');
     shift @ARGV;
 }

From 2bac97ca3b74b0233bb4d88806e8df848dc533ed Mon Sep 17 00:00:00 2001
From: Nicolas Boulenguez <nicolas.boulenguez@free.fr>
Date: Mon, 20 Apr 2026 00:36:38 +0200
Subject: [PATCH 08/10] perl: set readline raw mode during tests

---
 Makefile       | 2 +-
 impls/perl/run | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/Makefile b/Makefile
index ff1cd7a643..6eda0955a2 100644
--- a/Makefile
+++ b/Makefile
@@ -168,7 +168,7 @@ get_run_prefix = $(strip $(foreach mode,$(call actual_impl,$(1))_MODE, \
 
 # Takes impl and step
 # Returns the runtest command prefix (with runtest options) for testing the given step
-get_runtest_cmd = $(call get_run_prefix,$(1),$(2),$(if $(filter cs fsharp mal tcl vb,$(1)),RAW=1,)) \
+get_runtest_cmd = $(call get_run_prefix,$(1),$(2),$(if $(filter cs fsharp mal perl tcl vb,$(1)),RAW=1)) \
 		    ../../runtest.py $(opt_HARD) $(opt_DEFERRABLE) $(opt_OPTIONAL) $(call $(1)_TEST_OPTS) $(TEST_OPTS)
 
 # Takes impl and step
diff --git a/impls/perl/run b/impls/perl/run
index 4f255fe5fe..a388a0c3ce 100755
--- a/impls/perl/run
+++ b/impls/perl/run
@@ -1,2 +1,2 @@
 #!/usr/bin/env bash
-exec perl $(dirname $0)/${STEP:-stepA_mal}.pl "${@}"
+exec perl $(dirname $0)/${STEP:-stepA_mal}.pl ${RAW:+--raw} "$@"

From 7d81acc0d85d6839388e1a400d596b7e676a6a85 Mon Sep 17 00:00:00 2001
From: Nicolas Boulenguez <nicolas.boulenguez@free.fr>
Date: Sun, 19 Apr 2026 16:29:30 +0200
Subject: [PATCH 09/10] run scripts: improve style

---
 impls/ada.2/run         |  2 +-
 impls/ada/run           |  2 +-
 impls/awk/run           |  2 +-
 impls/bash/run          |  2 +-
 impls/basic/run         | 12 ++++++++----
 impls/bbc-basic/run     |  2 +-
 impls/c.2/run           |  2 +-
 impls/c/run             |  2 +-
 impls/chuck/run         | 20 ++++++++++++++------
 impls/clojure/run       | 13 +++++++------
 impls/coffee/run        |  2 +-
 impls/common-lisp/run   |  2 +-
 impls/cpp/run           |  2 +-
 impls/crystal/run       |  2 +-
 impls/cs/run            |  2 +-
 impls/d/run             |  2 +-
 impls/dart/run          |  2 +-
 impls/elisp/run         |  4 +++-
 impls/elixir/run        |  2 +-
 impls/elm/run           |  2 +-
 impls/erlang/run        |  2 +-
 impls/es6/run           |  2 +-
 impls/factor/run        |  3 ++-
 impls/fennel/run        |  2 +-
 impls/forth/run         |  2 +-
 impls/fsharp/run        |  2 +-
 impls/gnu-smalltalk/run |  2 +-
 impls/go/run            |  2 +-
 impls/groovy/run        |  2 +-
 impls/guile/run         |  2 +-
 impls/hare/run          |  2 +-
 impls/haskell/run       |  2 +-
 impls/haxe/run          | 10 +++++-----
 impls/hy/run            |  2 +-
 impls/janet/run         |  2 +-
 impls/java/run          | 17 ++++++++---------
 impls/js/run            |  2 +-
 impls/julia/run         |  2 +-
 impls/kotlin/run        |  2 +-
 impls/livescript/run    |  2 +-
 impls/logo/run          |  2 +-
 impls/lua/run           |  2 +-
 impls/make/run          |  2 +-
 impls/mal/run           | 13 ++++++++-----
 impls/matlab/run        | 12 +++++-------
 impls/miniMAL/run       |  2 +-
 impls/nasm/run          |  2 +-
 impls/nim/run           |  2 +-
 impls/objc/run          |  2 +-
 impls/objpascal/run     |  2 +-
 impls/ocaml/run         |  2 +-
 impls/perl6/run         |  2 +-
 impls/php/run           |  2 +-
 impls/picolisp/run      |  2 +-
 impls/pike/run          |  2 +-
 impls/powershell/run    |  2 +-
 impls/prolog/run        |  2 +-
 impls/ps/run            |  2 +-
 impls/purs/run          |  2 +-
 impls/python2/run       |  2 +-
 impls/python3/run       |  2 +-
 impls/r/run             |  2 +-
 impls/racket/run        |  2 +-
 impls/rexx/run          |  2 +-
 impls/rpython/run       |  2 +-
 impls/ruby.2/run        |  2 +-
 impls/ruby/run          |  2 +-
 impls/rust/run          |  2 +-
 impls/scala/run         |  2 +-
 impls/scheme/run        | 16 ++++++++--------
 impls/skew/run          |  2 +-
 impls/sml/run           |  2 +-
 impls/swift3/run        |  2 +-
 impls/swift4/run        |  2 +-
 impls/swift6/run        |  2 +-
 impls/tcl/run           |  2 +-
 impls/ts/run            |  2 +-
 impls/vala/run          |  2 +-
 impls/vb/run            |  2 +-
 impls/vbs/run           |  2 +-
 impls/vhdl/run          |  2 +-
 impls/wasm/run          | 15 +++++++--------
 impls/wren/run          |  2 +-
 impls/yorick/run        |  2 +-
 impls/zig/run           |  2 +-
 85 files changed, 149 insertions(+), 134 deletions(-)

diff --git a/impls/ada.2/run b/impls/ada.2/run
index 6efdc3de32..57693e8022 100755
--- a/impls/ada.2/run
+++ b/impls/ada.2/run
@@ -1,2 +1,2 @@
 #!/bin/sh
-exec $(dirname $0)/${STEP:-stepA_mal} "${@}"
+exec $(dirname $0)/${STEP:-stepA_mal} "$@"
diff --git a/impls/ada/run b/impls/ada/run
index c66c2b81dc..6e11defbfb 100755
--- a/impls/ada/run
+++ b/impls/ada/run
@@ -1,2 +1,2 @@
 #!/usr/bin/env bash
-exec $(dirname $0)/${STEP:-stepA_mal} "${@}"
+exec $(dirname $0)/${STEP:-stepA_mal} "$@"
diff --git a/impls/awk/run b/impls/awk/run
index 035bed1e3f..c3cfdf6044 100755
--- a/impls/awk/run
+++ b/impls/awk/run
@@ -1,2 +1,2 @@
 #!/usr/bin/env bash
-exec awk -f $(dirname $0)/${STEP:-stepA_mal}.awk "${@}"
+exec awk -f $(dirname $0)/${STEP:-stepA_mal}.awk "$@"
diff --git a/impls/bash/run b/impls/bash/run
index 05081b9ce6..29e282a6af 100755
--- a/impls/bash/run
+++ b/impls/bash/run
@@ -1,2 +1,2 @@
 #!/usr/bin/env bash
-exec bash $(dirname $0)/${STEP:-stepA_mal}.sh "${@}"
+exec bash $(dirname $0)/${STEP:-stepA_mal}.sh "$@"
diff --git a/impls/basic/run b/impls/basic/run
index 9b394f8c0b..82b00367bb 100755
--- a/impls/basic/run
+++ b/impls/basic/run
@@ -1,8 +1,12 @@
 #!/usr/bin/env bash
 cd $(dirname $0)
-(echo "(def! -*ARGS*- (list $(for a in "${@}"; do echo -n " \"${a}\""; done)))") > .args.mal
+{
+    printf '(def! -*ARGS*- (list'
+    [ $# = 0 ] || printf ' "%s"' "$@"
+    echo '))'
+} > .args.mal
 case ${basic_MODE:-cbm} in
-    cbm)    exec cbmbasic ${STEP:-stepA_mal}.bas "${@}" ;;
-    qbasic) exec ./${STEP:-stepA_mal} "${@}" ;;
-    *)      echo "Invalid basic_MODE: ${basic_MODE}"; exit 2 ;;
+    cbm)    exec cbmbasic ${STEP:-stepA_mal}.bas "$@" ;;
+    qbasic) exec ./${STEP:-stepA_mal} "$@" ;;
+    *)      echo "Invalid basic_MODE: $basic_MODE"; exit 2 ;;
 esac
diff --git a/impls/bbc-basic/run b/impls/bbc-basic/run
index b3e2049a09..1e3b0523a0 100755
--- a/impls/bbc-basic/run
+++ b/impls/bbc-basic/run
@@ -1,3 +1,3 @@
 #!/usr/bin/env bash
 exec "${BRANDY:-sbrandy}" -size 1024k \
-    -path ../bbc-basic -quit $(dirname $0)/${STEP:-stepA_mal}.bas "${@}"
+    -path ../bbc-basic -quit $(dirname $0)/${STEP:-stepA_mal}.bas "$@"
diff --git a/impls/c.2/run b/impls/c.2/run
index 6efdc3de32..57693e8022 100755
--- a/impls/c.2/run
+++ b/impls/c.2/run
@@ -1,2 +1,2 @@
 #!/bin/sh
-exec $(dirname $0)/${STEP:-stepA_mal} "${@}"
+exec $(dirname $0)/${STEP:-stepA_mal} "$@"
diff --git a/impls/c/run b/impls/c/run
index c66c2b81dc..6e11defbfb 100755
--- a/impls/c/run
+++ b/impls/c/run
@@ -1,2 +1,2 @@
 #!/usr/bin/env bash
-exec $(dirname $0)/${STEP:-stepA_mal} "${@}"
+exec $(dirname $0)/${STEP:-stepA_mal} "$@"
diff --git a/impls/chuck/run b/impls/chuck/run
index 99137daea7..7f7e1e5d97 100755
--- a/impls/chuck/run
+++ b/impls/chuck/run
@@ -1,11 +1,19 @@
 #!/usr/bin/env bash
+step=$(dirname $0)/${STEP:-stepA_mal}.ck
+
 regex_chugin=${REGEX_CHUGIN:-/usr/local/lib/chuck/1.5.2.5/RegEx.chug}
-if [[ ! -f "$regex_chugin" ]]; then
-    echo "Set \$REGEX_CHUGIN to the absolute path of RegEx.chug"; exit 1
+if [ ! -f "$regex_chugin" ]; then
+    echo 'Set $REGEX_CHUGIN to the absolute path of RegEx.chug'
+    exit 1
 fi
 
-imports=$(grep "^ *// *@import" "$(dirname $0)/${STEP:-stepA_mal}.ck" | awk '{print $3}')
-imports=$(for i in ${imports}; do ls $(dirname $0)/${i}; done)
-old_IFS="${IFS}"; IFS=$'\a'; export CHUCK_ARGS="${*}"; IFS="${old_IFS}"
+imports=$(sed -n "s|^ *// *@import *|$(dirname $0)/|p" $step)
+
+separator=$(printf '\a')
+for x; do
+    CHUCK_ARGS="${CHUCK_ARGS:+$CHUCK_ARGS$separator}$x"
+done
+export CHUCK_ARGS
 
-exec chuck --caution-to-the-wind --silent --chugin:"$regex_chugin" ${imports} $(dirname $-1)/${STEP:-stepA_mal}.ck
+exec chuck --caution-to-the-wind --silent --chugin:"$regex_chugin" \
+     $imports $step
diff --git a/impls/clojure/run b/impls/clojure/run
index 5fe4d92804..1005d79779 100755
--- a/impls/clojure/run
+++ b/impls/clojure/run
@@ -1,8 +1,9 @@
 #!/usr/bin/env bash
-export PATH=$PATH:$(dirname $0)/node_modules/.bin
+export PATH="$PATH:$(dirname $0)/node_modules/.bin"
 STEP=${STEP:-stepA_mal}
-if [ "${clojure_MODE}" = "cljs" ]; then
-  exec lumo -c $(dirname $0)/src -m mal.${STEP//_/-} "${@}"
-else
-  exec java -jar $(dirname $0)/target/${STEP}.jar "${@}"
-fi
+case ${clojure_MODE:-clj} in
+    cljs) exec lumo -c $(dirname $0)/src -m mal.${STEP//_/-} "$@" ;;
+    clj)  exec java -jar $(dirname $0)/target/$STEP.jar "$@" ;;
+esac
+echo "Invalid clojure_MODE: $clojure_MODE"
+exit 1
diff --git a/impls/coffee/run b/impls/coffee/run
index 84deffb471..72d7c2817d 100755
--- a/impls/coffee/run
+++ b/impls/coffee/run
@@ -1,2 +1,2 @@
 #!/usr/bin/env bash
-exec coffee $(dirname $0)/${STEP:-stepA_mal}.coffee "${@}"
+exec coffee $(dirname $0)/${STEP:-stepA_mal}.coffee "$@"
diff --git a/impls/common-lisp/run b/impls/common-lisp/run
index c66c2b81dc..6e11defbfb 100755
--- a/impls/common-lisp/run
+++ b/impls/common-lisp/run
@@ -1,2 +1,2 @@
 #!/usr/bin/env bash
-exec $(dirname $0)/${STEP:-stepA_mal} "${@}"
+exec $(dirname $0)/${STEP:-stepA_mal} "$@"
diff --git a/impls/cpp/run b/impls/cpp/run
index c66c2b81dc..6e11defbfb 100755
--- a/impls/cpp/run
+++ b/impls/cpp/run
@@ -1,2 +1,2 @@
 #!/usr/bin/env bash
-exec $(dirname $0)/${STEP:-stepA_mal} "${@}"
+exec $(dirname $0)/${STEP:-stepA_mal} "$@"
diff --git a/impls/crystal/run b/impls/crystal/run
index a42a7e149d..3d36605e03 100755
--- a/impls/crystal/run
+++ b/impls/crystal/run
@@ -1,2 +1,2 @@
 #!/bin/sh
-exec $(dirname $0)/bin/${STEP:-stepA_mal} "${@}"
+exec $(dirname $0)/bin/${STEP:-stepA_mal} "$@"
diff --git a/impls/cs/run b/impls/cs/run
index 5c5642646f..91beef2d69 100755
--- a/impls/cs/run
+++ b/impls/cs/run
@@ -1,2 +1,2 @@
 #!/usr/bin/env bash
-exec mono $(dirname $0)/${STEP:-stepA_mal}.exe ${RAW:+--raw} "${@}"
+exec mono $(dirname $0)/${STEP:-stepA_mal}.exe ${RAW:+--raw} "$@"
diff --git a/impls/d/run b/impls/d/run
index c66c2b81dc..6e11defbfb 100755
--- a/impls/d/run
+++ b/impls/d/run
@@ -1,2 +1,2 @@
 #!/usr/bin/env bash
-exec $(dirname $0)/${STEP:-stepA_mal} "${@}"
+exec $(dirname $0)/${STEP:-stepA_mal} "$@"
diff --git a/impls/dart/run b/impls/dart/run
index 6f3ab8bca3..948a2a45a7 100755
--- a/impls/dart/run
+++ b/impls/dart/run
@@ -1,2 +1,2 @@
 #!/usr/bin/env bash
-exec dart --checked $(dirname $0)/${STEP:-stepA_mal}.dart "${@}"
+exec dart --checked $(dirname $0)/${STEP:-stepA_mal}.dart "$@"
diff --git a/impls/elisp/run b/impls/elisp/run
index cb0387403c..f14aebb10a 100755
--- a/impls/elisp/run
+++ b/impls/elisp/run
@@ -1,3 +1,5 @@
 #!/bin/sh
 dir=$(dirname $0)
-exec emacs -Q --batch -L $dir --eval "(setq text-quoting-style 'straight)" --load $dir/${STEP:-stepA_mal}.elc "${@}"
+exec emacs -Q --batch -L $dir \
+     --eval "(setq text-quoting-style 'straight)" \
+     --load $dir/${STEP:-stepA_mal}.elc "$@"
diff --git a/impls/elixir/run b/impls/elixir/run
index bfd505014b..191a56a45e 100755
--- a/impls/elixir/run
+++ b/impls/elixir/run
@@ -1,3 +1,3 @@
 #!/usr/bin/env bash
 cd $(dirname $0)
-exec mix ${STEP:-stepA_mal} "${@}"
+exec mix ${STEP:-stepA_mal} "$@"
diff --git a/impls/elm/run b/impls/elm/run
index d22e4fbeac..4cf42af657 100755
--- a/impls/elm/run
+++ b/impls/elm/run
@@ -1,2 +1,2 @@
 #!/usr/bin/env bash
-exec node $(dirname $0)/bootstrap.js ${STEP:-stepA_mal} "${@}"
+exec node $(dirname $0)/bootstrap.js ${STEP:-stepA_mal} "$@"
diff --git a/impls/erlang/run b/impls/erlang/run
index c66c2b81dc..6e11defbfb 100755
--- a/impls/erlang/run
+++ b/impls/erlang/run
@@ -1,2 +1,2 @@
 #!/usr/bin/env bash
-exec $(dirname $0)/${STEP:-stepA_mal} "${@}"
+exec $(dirname $0)/${STEP:-stepA_mal} "$@"
diff --git a/impls/es6/run b/impls/es6/run
index 54e8932d5c..b71faee4cd 100755
--- a/impls/es6/run
+++ b/impls/es6/run
@@ -1,2 +1,2 @@
 #!/usr/bin/env bash
-exec node $(dirname $0)/${STEP:-stepA_mal}.mjs "${@}"
+exec node $(dirname $0)/${STEP:-stepA_mal}.mjs "$@"
diff --git a/impls/factor/run b/impls/factor/run
index bb6d41f1da..812e8c3c01 100755
--- a/impls/factor/run
+++ b/impls/factor/run
@@ -1,2 +1,3 @@
 #!/usr/bin/env bash
-exec factor $(dirname $0)/${STEP:-stepA_mal}/${STEP:-stepA_mal}.factor "${@}"
+step=${STEP:-stepA_mal}
+exec factor $(dirname $0)/$step/$step.factor "$@"
diff --git a/impls/fennel/run b/impls/fennel/run
index 5842447c37..904ff718f6 100755
--- a/impls/fennel/run
+++ b/impls/fennel/run
@@ -1,3 +1,3 @@
 #!/usr/bin/env bash
 
-exec fennel $(dirname $0)/${STEP:-stepA_mal}.fnl "${@}"
+exec fennel $(dirname $0)/${STEP:-stepA_mal}.fnl "$@"
diff --git a/impls/forth/run b/impls/forth/run
index 0a45c57df5..9d9b6d77f1 100755
--- a/impls/forth/run
+++ b/impls/forth/run
@@ -1,2 +1,2 @@
 #!/usr/bin/env bash
-exec gforth $(dirname $0)/${STEP:-stepA_mal}.fs "${@}"
+exec gforth $(dirname $0)/${STEP:-stepA_mal}.fs "$@"
diff --git a/impls/fsharp/run b/impls/fsharp/run
index 5c5642646f..91beef2d69 100755
--- a/impls/fsharp/run
+++ b/impls/fsharp/run
@@ -1,2 +1,2 @@
 #!/usr/bin/env bash
-exec mono $(dirname $0)/${STEP:-stepA_mal}.exe ${RAW:+--raw} "${@}"
+exec mono $(dirname $0)/${STEP:-stepA_mal}.exe ${RAW:+--raw} "$@"
diff --git a/impls/gnu-smalltalk/run b/impls/gnu-smalltalk/run
index 740459af26..9e87a265dd 100755
--- a/impls/gnu-smalltalk/run
+++ b/impls/gnu-smalltalk/run
@@ -1,2 +1,2 @@
 #!/usr/bin/env bash
-exec gst -f $(dirname $0)/${STEP:-stepA_mal}.st "${@}"
+exec gst -f $(dirname $0)/${STEP:-stepA_mal}.st "$@"
diff --git a/impls/go/run b/impls/go/run
index c66c2b81dc..6e11defbfb 100755
--- a/impls/go/run
+++ b/impls/go/run
@@ -1,2 +1,2 @@
 #!/usr/bin/env bash
-exec $(dirname $0)/${STEP:-stepA_mal} "${@}"
+exec $(dirname $0)/${STEP:-stepA_mal} "$@"
diff --git a/impls/groovy/run b/impls/groovy/run
index b64ea39452..fff2753561 100755
--- a/impls/groovy/run
+++ b/impls/groovy/run
@@ -1,2 +1,2 @@
 #!/usr/bin/env bash
-exec groovy $(dirname $0)/${STEP:-stepA_mal}.groovy "${@}"
+exec groovy $(dirname $0)/${STEP:-stepA_mal}.groovy "$@"
diff --git a/impls/guile/run b/impls/guile/run
index 6d9e58d123..0e133613f4 100755
--- a/impls/guile/run
+++ b/impls/guile/run
@@ -1,3 +1,3 @@
 #!/usr/bin/env bash
 # XDG_CACHE_HOME is where guile stores the compiled files
-XDG_CACHE_HOME=.cache/ exec guile -L $(dirname $0) $(dirname $0)/${STEP:-stepA_mal}.scm "${@}"
+XDG_CACHE_HOME=.cache/ exec guile -L $(dirname $0) $(dirname $0)/${STEP:-stepA_mal}.scm "$@"
diff --git a/impls/hare/run b/impls/hare/run
index 373d352735..81319040b2 100755
--- a/impls/hare/run
+++ b/impls/hare/run
@@ -1,3 +1,3 @@
 #!/usr/bin/env bash
 
-exec $(dirname $0)/${STEP:-stepA_mal} "${@}"
\ No newline at end of file
+exec $(dirname $0)/${STEP:-stepA_mal} "$@"
diff --git a/impls/haskell/run b/impls/haskell/run
index 6efdc3de32..57693e8022 100755
--- a/impls/haskell/run
+++ b/impls/haskell/run
@@ -1,2 +1,2 @@
 #!/bin/sh
-exec $(dirname $0)/${STEP:-stepA_mal} "${@}"
+exec $(dirname $0)/${STEP:-stepA_mal} "$@"
diff --git a/impls/haxe/run b/impls/haxe/run
index 3bb679ae65..f94b1e557a 100755
--- a/impls/haxe/run
+++ b/impls/haxe/run
@@ -1,8 +1,8 @@
 #!/usr/bin/env bash
 case ${haxe_MODE:-neko} in
-    neko)   exec neko    $(dirname $0)/${STEP:-stepA_mal}.n   "${@}" ;;
-    python) exec python3 $(dirname $0)/${STEP:-stepA_mal}.py  "${@}" ;;
-    js)     exec node    $(dirname $0)/${STEP:-stepA_mal}.js  "${@}" ;;
-    cpp)    exec         $(dirname $0)/cpp/${STEP:-stepA_mal} "${@}" ;;
-    *) echo "Invalid haxe_MODE: ${haxe_MODE}"; exit 2 ;;
+    neko)   exec neko    $(dirname $0)/${STEP:-stepA_mal}.n   "$@" ;;
+    python) exec python3 $(dirname $0)/${STEP:-stepA_mal}.py  "$@" ;;
+    js)     exec node    $(dirname $0)/${STEP:-stepA_mal}.js  "$@" ;;
+    cpp)    exec         $(dirname $0)/cpp/${STEP:-stepA_mal} "$@" ;;
+    *) echo "Invalid haxe_MODE: $haxe_MODE"; exit 2 ;;
 esac
diff --git a/impls/hy/run b/impls/hy/run
index 7f69c4e5d9..efe4b22686 100755
--- a/impls/hy/run
+++ b/impls/hy/run
@@ -1,2 +1,2 @@
 #!/usr/bin/env bash
-exec hy $(dirname $0)/${STEP:-stepA_mal}.hy "${@}"
+exec hy $(dirname $0)/${STEP:-stepA_mal}.hy "$@"
diff --git a/impls/janet/run b/impls/janet/run
index f4782c8fae..e06e39a8d4 100755
--- a/impls/janet/run
+++ b/impls/janet/run
@@ -1,2 +1,2 @@
 #!/bin/sh
-exec janet $(dirname $0)/${STEP:-stepA_mal}.janet "${@}"
+exec janet $(dirname $0)/${STEP:-stepA_mal}.janet "$@"
diff --git a/impls/java/run b/impls/java/run
index 670f45c4db..567e9f649c 100755
--- a/impls/java/run
+++ b/impls/java/run
@@ -1,9 +1,8 @@
-#!/usr/bin/env bash
-args=""
-if [ "$#" -gt 0 ]; then
-    args="-Dexec.args='$1'"
-    for a in "${@:2}"; do
-        args="$args '$a'"
-    done
-fi
-exec mvn -quiet -e exec:java -Dexec.mainClass="mal.${STEP:-stepA_mal}" ${args:+"$args"}
+#!/bin/sh
+set -Cefu
+for a; do
+    args="${args:+$args }'$a'"
+done
+exec mvn -quiet -e exec:java \
+     -Dexec.mainClass=mal.${STEP:-stepA_mal} \
+     ${args:+"-Dexec.args=$args"}
diff --git a/impls/js/run b/impls/js/run
index 1148122a23..893cbb59c7 100755
--- a/impls/js/run
+++ b/impls/js/run
@@ -1,2 +1,2 @@
 #!/usr/bin/env bash
-exec node $(dirname $0)/${STEP:-stepA_mal}.js "${@}"
+exec node $(dirname $0)/${STEP:-stepA_mal}.js "$@"
diff --git a/impls/julia/run b/impls/julia/run
index dd149451f1..5791967a12 100755
--- a/impls/julia/run
+++ b/impls/julia/run
@@ -1,2 +1,2 @@
 #!/usr/bin/env bash
-exec julia $(dirname $0)/${STEP:-stepA_mal}.jl "${@}"
+exec julia $(dirname $0)/${STEP:-stepA_mal}.jl "$@"
diff --git a/impls/kotlin/run b/impls/kotlin/run
index c5a1f3c10f..0dce7b02a0 100755
--- a/impls/kotlin/run
+++ b/impls/kotlin/run
@@ -1,2 +1,2 @@
 #!/usr/bin/env bash
-exec java -jar $(dirname $0)/${STEP:-stepA_mal}.jar "${@}"
+exec java -jar $(dirname $0)/${STEP:-stepA_mal}.jar "$@"
diff --git a/impls/livescript/run b/impls/livescript/run
index 1148122a23..893cbb59c7 100755
--- a/impls/livescript/run
+++ b/impls/livescript/run
@@ -1,2 +1,2 @@
 #!/usr/bin/env bash
-exec node $(dirname $0)/${STEP:-stepA_mal}.js "${@}"
+exec node $(dirname $0)/${STEP:-stepA_mal}.js "$@"
diff --git a/impls/logo/run b/impls/logo/run
index f4a73d98c1..065ff2b5d5 100755
--- a/impls/logo/run
+++ b/impls/logo/run
@@ -1,2 +1,2 @@
 #!/usr/bin/env bash
-exec ucblogo $(dirname $0)/${STEP:-stepA_mal}.lg - "${@}"
+exec ucblogo $(dirname $0)/${STEP:-stepA_mal}.lg - "$@"
diff --git a/impls/lua/run b/impls/lua/run
index a53fbc60ba..87847a41e6 100755
--- a/impls/lua/run
+++ b/impls/lua/run
@@ -1,2 +1,2 @@
 #!/usr/bin/env bash
-exec lua $(dirname $0)/${STEP:-stepA_mal}.lua "${@}"
+exec lua $(dirname $0)/${STEP:-stepA_mal}.lua "$@"
diff --git a/impls/make/run b/impls/make/run
index 43b9344665..9a10a4e51d 100755
--- a/impls/make/run
+++ b/impls/make/run
@@ -1,2 +1,2 @@
 #!/usr/bin/env bash
-exec make --no-print-directory -f $(dirname $0)/${STEP:-stepA_mal}.mk "${@}"
+exec make --no-print-directory -f $(dirname $0)/${STEP:-stepA_mal}.mk "$@"
diff --git a/impls/mal/run b/impls/mal/run
index 3bf6b5b09c..5b48bd55bb 100755
--- a/impls/mal/run
+++ b/impls/mal/run
@@ -1,9 +1,12 @@
 #!/usr/bin/env bash
 MAL_FILE=../mal/${STEP:-stepA_mal}.mal
 export STEP=stepA_mal # force MAL_IMPL to use stepA
-case ${MAL_IMPL} in
-*-mal)
-    MAL_IMPL=${MAL_IMPL%%-mal}
-    MAL_FILE="../mal/stepA_mal.mal ${MAL_FILE}" ;;
+impl=${MAL_IMPL:-js}
+case $impl in
+    *-mal)
+        exec ../${impl%-mal}/run ../mal/stepA_mal.mal $MAL_FILE "$@"
+        ;;
+    *)
+        exec ../$impl/run $MAL_FILE "$@"
+        ;;
 esac
-exec ./../${MAL_IMPL:-js}/run ${MAL_FILE} "${@}"
diff --git a/impls/matlab/run b/impls/matlab/run
index 332c5903de..6181b298e0 100755
--- a/impls/matlab/run
+++ b/impls/matlab/run
@@ -1,21 +1,19 @@
 #!/bin/sh
 
-args=
 for x; do
-    args="$args${args:+, }'$x'"
+    args="${args:+$args, }'$x'"
 done
+prompt="${STEP:-stepA_mal}(${args:-});quit;"
 
-case "$matlab_MODE" in
+case ${matlab_MODE:-octave} in
     matlab)
-        options='-nodisplay -nosplash -nodesktop -nojvm -r'
+        exec matlab -nodisplay -nosplash -nodesktop -nojvm -r "$prompt"
         ;;
     octave)
-        options='-q --no-gui --no-history --eval'
+        exec octave -q --no-gui --no-history --eval "$prompt"
         ;;
     *)
         echo "Bad matlab_MODE: $matlab_MODE"
         exit 1
         ;;
 esac
-
-exec $matlab_MODE $options "${STEP:-stepA_mal}($args);quit;"
diff --git a/impls/miniMAL/run b/impls/miniMAL/run
index 5fe9482d6e..df66bc329c 100755
--- a/impls/miniMAL/run
+++ b/impls/miniMAL/run
@@ -1,3 +1,3 @@
 #!/usr/bin/env bash
 cd $(dirname $0)
-exec miniMAL ./${STEP:-stepA_mal}.json "${@}"
+exec miniMAL ./${STEP:-stepA_mal}.json "$@"
diff --git a/impls/nasm/run b/impls/nasm/run
index 016cc72d79..7933a7939f 100755
--- a/impls/nasm/run
+++ b/impls/nasm/run
@@ -1,3 +1,3 @@
 #!/usr/bin/env bash
-exec $(dirname $0)/${STEP:-stepA_mal} "${@}"
+exec $(dirname $0)/${STEP:-stepA_mal} "$@"
 
diff --git a/impls/nim/run b/impls/nim/run
index 6efdc3de32..57693e8022 100755
--- a/impls/nim/run
+++ b/impls/nim/run
@@ -1,2 +1,2 @@
 #!/bin/sh
-exec $(dirname $0)/${STEP:-stepA_mal} "${@}"
+exec $(dirname $0)/${STEP:-stepA_mal} "$@"
diff --git a/impls/objc/run b/impls/objc/run
index c66c2b81dc..6e11defbfb 100755
--- a/impls/objc/run
+++ b/impls/objc/run
@@ -1,2 +1,2 @@
 #!/usr/bin/env bash
-exec $(dirname $0)/${STEP:-stepA_mal} "${@}"
+exec $(dirname $0)/${STEP:-stepA_mal} "$@"
diff --git a/impls/objpascal/run b/impls/objpascal/run
index c66c2b81dc..6e11defbfb 100755
--- a/impls/objpascal/run
+++ b/impls/objpascal/run
@@ -1,2 +1,2 @@
 #!/usr/bin/env bash
-exec $(dirname $0)/${STEP:-stepA_mal} "${@}"
+exec $(dirname $0)/${STEP:-stepA_mal} "$@"
diff --git a/impls/ocaml/run b/impls/ocaml/run
index 6efdc3de32..57693e8022 100755
--- a/impls/ocaml/run
+++ b/impls/ocaml/run
@@ -1,2 +1,2 @@
 #!/bin/sh
-exec $(dirname $0)/${STEP:-stepA_mal} "${@}"
+exec $(dirname $0)/${STEP:-stepA_mal} "$@"
diff --git a/impls/perl6/run b/impls/perl6/run
index 80cb92b34b..8a58ac8a01 100755
--- a/impls/perl6/run
+++ b/impls/perl6/run
@@ -1,2 +1,2 @@
 #!/usr/bin/env bash
-exec perl6 $(dirname $0)/${STEP:-stepA_mal}.pl "${@}"
+exec perl6 $(dirname $0)/${STEP:-stepA_mal}.pl "$@"
diff --git a/impls/php/run b/impls/php/run
index daf97f93c0..ef22b62eb3 100755
--- a/impls/php/run
+++ b/impls/php/run
@@ -1,2 +1,2 @@
 #!/usr/bin/env bash
-exec php $(dirname $0)/${STEP:-stepA_mal}.php "${@}"
+exec php $(dirname $0)/${STEP:-stepA_mal}.php "$@"
diff --git a/impls/picolisp/run b/impls/picolisp/run
index a7f77da3fd..a9f757b2d9 100755
--- a/impls/picolisp/run
+++ b/impls/picolisp/run
@@ -1,2 +1,2 @@
 #!/usr/bin/env bash
-exec pil $(dirname $0)/${STEP:-stepA_mal}.l - "${@}"
+exec pil $(dirname $0)/${STEP:-stepA_mal}.l - "$@"
diff --git a/impls/pike/run b/impls/pike/run
index 1281d967de..8b74b25265 100755
--- a/impls/pike/run
+++ b/impls/pike/run
@@ -1,2 +1,2 @@
 #!/usr/bin/env bash
-exec pike $(dirname $0)/${STEP:-stepA_mal}.pike "${@}"
+exec pike $(dirname $0)/${STEP:-stepA_mal}.pike "$@"
diff --git a/impls/powershell/run b/impls/powershell/run
index 7adde42817..0927bcdcea 100755
--- a/impls/powershell/run
+++ b/impls/powershell/run
@@ -1,2 +1,2 @@
 #!/bin/sh
-exec powershell $(dirname $0)/${STEP:-stepA_mal}.ps1 "${@}"
+exec powershell $(dirname $0)/${STEP:-stepA_mal}.ps1 "$@"
diff --git a/impls/prolog/run b/impls/prolog/run
index 6a9b5f1fe4..908d180b8b 100755
--- a/impls/prolog/run
+++ b/impls/prolog/run
@@ -1,2 +1,2 @@
 #!/usr/bin/env bash
-exec swipl $(dirname $0)/${STEP:-stepA_mal}.pl "${@}"
+exec swipl $(dirname $0)/${STEP:-stepA_mal}.pl "$@"
diff --git a/impls/ps/run b/impls/ps/run
index a961d13c7f..dde80e1f66 100755
--- a/impls/ps/run
+++ b/impls/ps/run
@@ -1,2 +1,2 @@
 #!/usr/bin/env bash
-exec gs -q -I$(dirname $0) -dNOSAFER -dNODISPLAY -- $(dirname $0)/${STEP:-stepA_mal}.ps "${@}"
+exec gs -q -I$(dirname $0) -dNOSAFER -dNODISPLAY -- $(dirname $0)/${STEP:-stepA_mal}.ps "$@"
diff --git a/impls/purs/run b/impls/purs/run
index 510f226881..893cbb59c7 100755
--- a/impls/purs/run
+++ b/impls/purs/run
@@ -1,2 +1,2 @@
 #!/usr/bin/env bash
-exec node $(dirname $0)/${STEP:-stepA_mal}.js "${@}"
\ No newline at end of file
+exec node $(dirname $0)/${STEP:-stepA_mal}.js "$@"
diff --git a/impls/python2/run b/impls/python2/run
index 095e1963d0..2c41196a13 100755
--- a/impls/python2/run
+++ b/impls/python2/run
@@ -1,2 +1,2 @@
 #!/bin/sh
-exec python2 $(dirname $0)/${STEP:-stepA_mal}.py "${@}"
+exec python2 $(dirname $0)/${STEP:-stepA_mal}.py "$@"
diff --git a/impls/python3/run b/impls/python3/run
index 1e7632cd57..9b7b01bfba 100755
--- a/impls/python3/run
+++ b/impls/python3/run
@@ -1,2 +1,2 @@
 #!/bin/sh
-exec python3 $(dirname $0)/${STEP:-stepA_mal}.py "${@}"
+exec python3 $(dirname $0)/${STEP:-stepA_mal}.py "$@"
diff --git a/impls/r/run b/impls/r/run
index 916876f09d..9675392139 100755
--- a/impls/r/run
+++ b/impls/r/run
@@ -1,2 +1,2 @@
 #!/usr/bin/env bash
-exec Rscript $(dirname $0)/${STEP:-stepA_mal}.r "${@}"
+exec Rscript $(dirname $0)/${STEP:-stepA_mal}.r "$@"
diff --git a/impls/racket/run b/impls/racket/run
index fa0719bdce..07cc20aa3f 100755
--- a/impls/racket/run
+++ b/impls/racket/run
@@ -1,2 +1,2 @@
 #!/usr/bin/env bash
-exec racket $(dirname $0)/${STEP:-stepA_mal}.rkt "${@}"
+exec racket $(dirname $0)/${STEP:-stepA_mal}.rkt "$@"
diff --git a/impls/rexx/run b/impls/rexx/run
index b911329610..a38c60a0c6 100755
--- a/impls/rexx/run
+++ b/impls/rexx/run
@@ -1,2 +1,2 @@
 #!/bin/sh
-exec rexx -a $(dirname $0)/${STEP:-stepA_mal}.rexxpp "${@}"
+exec rexx -a $(dirname $0)/${STEP:-stepA_mal}.rexxpp "$@"
diff --git a/impls/rpython/run b/impls/rpython/run
index c66c2b81dc..6e11defbfb 100755
--- a/impls/rpython/run
+++ b/impls/rpython/run
@@ -1,2 +1,2 @@
 #!/usr/bin/env bash
-exec $(dirname $0)/${STEP:-stepA_mal} "${@}"
+exec $(dirname $0)/${STEP:-stepA_mal} "$@"
diff --git a/impls/ruby.2/run b/impls/ruby.2/run
index 980db0d659..c1acbcbbfb 100755
--- a/impls/ruby.2/run
+++ b/impls/ruby.2/run
@@ -1,2 +1,2 @@
 #!/usr/bin/env bash
-exec ruby $(dirname $0)/${STEP:-stepA_mal}.rb "${@}"
+exec ruby $(dirname $0)/${STEP:-stepA_mal}.rb "$@"
diff --git a/impls/ruby/run b/impls/ruby/run
index 980db0d659..c1acbcbbfb 100755
--- a/impls/ruby/run
+++ b/impls/ruby/run
@@ -1,2 +1,2 @@
 #!/usr/bin/env bash
-exec ruby $(dirname $0)/${STEP:-stepA_mal}.rb "${@}"
+exec ruby $(dirname $0)/${STEP:-stepA_mal}.rb "$@"
diff --git a/impls/rust/run b/impls/rust/run
index d67524c747..a86855ad8d 100755
--- a/impls/rust/run
+++ b/impls/rust/run
@@ -1,2 +1,2 @@
 #!/bin/sh
-exec $(dirname $0)/target/release/${STEP:-stepA_mal} "${@}"
+exec $(dirname $0)/target/release/${STEP:-stepA_mal} "$@"
diff --git a/impls/scala/run b/impls/scala/run
index eb06292ab5..aec8710d86 100755
--- a/impls/scala/run
+++ b/impls/scala/run
@@ -1,2 +1,2 @@
 #!/usr/bin/env bash
-exec java -classpath "$(dirname $0)/target/scala-2.11/mal.jar" "${STEP:-stepA_mal}" "$@"
+exec java -classpath "$(dirname $0)/target/scala-2.11/mal.jar" ${STEP:-stepA_mal} "$@"
diff --git a/impls/scheme/run b/impls/scheme/run
index acef8c0753..72fda6bcc8 100755
--- a/impls/scheme/run
+++ b/impls/scheme/run
@@ -3,7 +3,7 @@ basedir=$(dirname $0)
 step=${STEP:-stepA_mal}
 
 case ${scheme_MODE:-chibi} in
-    chibi)       exec chibi-scheme -I$basedir $basedir/$step.scm      "${@}" ;;
+    chibi)       exec chibi-scheme -I$basedir $basedir/$step.scm      "$@" ;;
     kawa)        if [ -e /usr/share/kawa/lib/kawa.jar ]; then
                      kawa=/usr/share/kawa/lib/kawa.jar
                   elif [ -e /usr/local/share/kawa/lib/kawa.jar ]; then
@@ -12,9 +12,9 @@ case ${scheme_MODE:-chibi} in
                      echo >&2 'Failed to find kawa.jar.'
                      exit 1
                  fi
-                 exec java -cp $kawa:$basedir/out $step               "${@}" ;;
-    gauche)      exec gosh -I$basedir $basedir/$step.scm              "${@}" ;;
-    chicken)     CHICKEN_REPOSITORY=$basedir/eggs exec $basedir/$step "${@}" ;;
+                 exec java -cp $kawa:$basedir/out $step               "$@" ;;
+    gauche)      exec gosh -I$basedir $basedir/$step.scm              "$@" ;;
+    chicken)     CHICKEN_REPOSITORY=$basedir/eggs exec $basedir/$step "$@" ;;
     sagittarius) if command -v sash >/dev/null 2>&1; then
                      sagittarius=sash
                  elif command -v sagittarius >/dev/null 2>&1; then
@@ -23,8 +23,8 @@ case ${scheme_MODE:-chibi} in
                      echo >&2 'Failed to find sash or sagittarius.'
                      exit 1
                  fi
-                 exec $sagittarius -n -L$basedir $basedir/$step.scm   "${@}" ;;
-    cyclone)     exec $basedir/$step                                  "${@}" ;;
-    foment)      exec foment $basedir/$step.scm                       "${@}" ;;
-    *) echo "Invalid scheme_MODE: ${scheme_MODE}"; exit 2 ;;
+                 exec $sagittarius -n -L$basedir $basedir/$step.scm   "$@" ;;
+    cyclone)     exec $basedir/$step                                  "$@" ;;
+    foment)      exec foment $basedir/$step.scm                       "$@" ;;
+    *) echo "Invalid scheme_MODE: $scheme_MODE"; exit 2 ;;
 esac
diff --git a/impls/skew/run b/impls/skew/run
index 1148122a23..893cbb59c7 100755
--- a/impls/skew/run
+++ b/impls/skew/run
@@ -1,2 +1,2 @@
 #!/usr/bin/env bash
-exec node $(dirname $0)/${STEP:-stepA_mal}.js "${@}"
+exec node $(dirname $0)/${STEP:-stepA_mal}.js "$@"
diff --git a/impls/sml/run b/impls/sml/run
index c66c2b81dc..6e11defbfb 100755
--- a/impls/sml/run
+++ b/impls/sml/run
@@ -1,2 +1,2 @@
 #!/usr/bin/env bash
-exec $(dirname $0)/${STEP:-stepA_mal} "${@}"
+exec $(dirname $0)/${STEP:-stepA_mal} "$@"
diff --git a/impls/swift3/run b/impls/swift3/run
index c66c2b81dc..6e11defbfb 100755
--- a/impls/swift3/run
+++ b/impls/swift3/run
@@ -1,2 +1,2 @@
 #!/usr/bin/env bash
-exec $(dirname $0)/${STEP:-stepA_mal} "${@}"
+exec $(dirname $0)/${STEP:-stepA_mal} "$@"
diff --git a/impls/swift4/run b/impls/swift4/run
index c66c2b81dc..6e11defbfb 100755
--- a/impls/swift4/run
+++ b/impls/swift4/run
@@ -1,2 +1,2 @@
 #!/usr/bin/env bash
-exec $(dirname $0)/${STEP:-stepA_mal} "${@}"
+exec $(dirname $0)/${STEP:-stepA_mal} "$@"
diff --git a/impls/swift6/run b/impls/swift6/run
index 8003dd69cb..8a2cee3d04 100755
--- a/impls/swift6/run
+++ b/impls/swift6/run
@@ -1,2 +1,2 @@
 #!/bin/sh
-exec $(dirname $0)/.build/${STEP:-stepA_mal} "${@}"
+exec $(dirname $0)/.build/${STEP:-stepA_mal} "$@"
diff --git a/impls/tcl/run b/impls/tcl/run
index 700b5291b0..443068da76 100755
--- a/impls/tcl/run
+++ b/impls/tcl/run
@@ -1,2 +1,2 @@
 #!/usr/bin/env bash
-exec tclsh $(dirname $0)/${STEP:-stepA_mal}.tcl ${RAW:+--raw} "${@}"
+exec tclsh $(dirname $0)/${STEP:-stepA_mal}.tcl ${RAW:+--raw} "$@"
diff --git a/impls/ts/run b/impls/ts/run
index 1148122a23..893cbb59c7 100755
--- a/impls/ts/run
+++ b/impls/ts/run
@@ -1,2 +1,2 @@
 #!/usr/bin/env bash
-exec node $(dirname $0)/${STEP:-stepA_mal}.js "${@}"
+exec node $(dirname $0)/${STEP:-stepA_mal}.js "$@"
diff --git a/impls/vala/run b/impls/vala/run
index c66c2b81dc..6e11defbfb 100755
--- a/impls/vala/run
+++ b/impls/vala/run
@@ -1,2 +1,2 @@
 #!/usr/bin/env bash
-exec $(dirname $0)/${STEP:-stepA_mal} "${@}"
+exec $(dirname $0)/${STEP:-stepA_mal} "$@"
diff --git a/impls/vb/run b/impls/vb/run
index 5c5642646f..91beef2d69 100755
--- a/impls/vb/run
+++ b/impls/vb/run
@@ -1,2 +1,2 @@
 #!/usr/bin/env bash
-exec mono $(dirname $0)/${STEP:-stepA_mal}.exe ${RAW:+--raw} "${@}"
+exec mono $(dirname $0)/${STEP:-stepA_mal}.exe ${RAW:+--raw} "$@"
diff --git a/impls/vbs/run b/impls/vbs/run
index 3c1aed2dd3..ec0a7aba16 100644
--- a/impls/vbs/run
+++ b/impls/vbs/run
@@ -1,4 +1,4 @@
 #!/usr/bin/env bash
 MAL_VBS_IMPL_NO_STDERR=1 MAL_VBS_IMPL_ECHO_STDIN=1 \
 WSLENV=MAL_VBS_IMPL_NO_STDERR/w:MAL_VBS_IMPL_ECHO_STDIN/w \
-cscript.exe -nologo "`wslpath -w "$(dirname $0)/${STEP:-stepA_mal}.vbs"`" "${@}"
\ No newline at end of file
+exec cscript.exe -nologo "`wslpath -w "$(dirname $0)/${STEP:-stepA_mal}.vbs"`" "$@"
diff --git a/impls/vhdl/run b/impls/vhdl/run
index 0d3a5d40c4..2e60d28742 100755
--- a/impls/vhdl/run
+++ b/impls/vhdl/run
@@ -7,7 +7,7 @@
 
 bin="$(dirname $0)/${STEP:-stepA_mal}"
 
-for arg in "$@" ; do
+for arg; do
     echo "$arg"
 done > vhdl_argv.tmp
 
diff --git a/impls/wasm/run b/impls/wasm/run
index 29c44131c2..764b5d920f 100755
--- a/impls/wasm/run
+++ b/impls/wasm/run
@@ -1,18 +1,17 @@
 #!/usr/bin/env bash
-STEP=${STEP:-stepA_mal}
-case "${wasm_MODE}" in
+case ${wasm_MODE:-js} in
 wasmtime)
-    exec wasmtime --dir=./ --dir=../ --dir=/ $(dirname $0)/${STEP:-stepA_mal}.wasm "${@}" ;;
+    exec wasmtime --dir=./ --dir=../ --dir=/ $(dirname $0)/${STEP:-stepA_mal}.wasm "$@" ;;
 wasmer)
-    exec wasmer run --dir=./ --dir=../ --dir=/ $(dirname $0)/${STEP:-stepA_mal}.wasm -- "${@}" ;;
+    exec wasmer run --dir=./ --dir=../ --dir=/ $(dirname $0)/${STEP:-stepA_mal}.wasm -- "$@" ;;
 warpy)
-    exec warpy --argv --memory-pages 256 $(dirname $0)/${STEP:-stepA_mal}.wasm "${@}" ;;
+    exec warpy --argv --memory-pages 256 $(dirname $0)/${STEP:-stepA_mal}.wasm "$@" ;;
 wax)
-    exec wax $(dirname $0)/${STEP:-stepA_mal}.wasm "${@}" ;;
+    exec wax $(dirname $0)/${STEP:-stepA_mal}.wasm "$@" ;;
 wace_libc)
-    exec wace $(dirname $0)/${STEP:-stepA_mal}.wasm "${@}" ;;
+    exec wace $(dirname $0)/${STEP:-stepA_mal}.wasm "$@" ;;
 wace_fooboot)
     echo >&2 "wace_fooboot mode not yet supported" ;;
 node|js|*)
-    exec node run.js $(dirname $0)/${STEP:-stepA_mal}.wasm "${@}" ;;
+    exec node run.js $(dirname $0)/${STEP:-stepA_mal}.wasm "$@" ;;
 esac
diff --git a/impls/wren/run b/impls/wren/run
index 8c269bf55a..f8cfe496d9 100755
--- a/impls/wren/run
+++ b/impls/wren/run
@@ -1,2 +1,2 @@
 #!/usr/bin/env bash
-exec wren $(dirname $0)/${STEP:-stepA_mal}.wren "${@}"
+exec wren $(dirname $0)/${STEP:-stepA_mal}.wren "$@"
diff --git a/impls/yorick/run b/impls/yorick/run
index 78b865fca2..4f35ebe814 100755
--- a/impls/yorick/run
+++ b/impls/yorick/run
@@ -1,3 +1,3 @@
 #!/usr/bin/env bash
 export YORICK_MAL_PATH="$(dirname $0)"
-exec yorick -batch "$YORICK_MAL_PATH/${STEP:-stepA_mal}.i" "${@}"
+exec yorick -batch "$YORICK_MAL_PATH/${STEP:-stepA_mal}.i" "$@"
diff --git a/impls/zig/run b/impls/zig/run
index 35613af46a..9b1b3df961 100755
--- a/impls/zig/run
+++ b/impls/zig/run
@@ -1,2 +1,2 @@
 #!/bin/sh
-exec $(dirname $0)/zig-out/bin/${STEP:-stepA_mal} "${@}"
+exec $(dirname $0)/zig-out/bin/${STEP:-stepA_mal} "$@"

From d2d001f857d81320e15e9c6ae2f6ed2f6e3ea2c2 Mon Sep 17 00:00:00 2001
From: Nicolas Boulenguez <nicolas.boulenguez@free.fr>
Date: Sat, 18 Apr 2026 18:34:29 +0200
Subject: [PATCH 10/10] Make explicit that each run script is executed in its
 own directory

The convention was already applied de facto:

* {latex3,scala}/run start by changing their working directory, so
  relative paths in command line arguments must be relative to the
  implementation directory.

* bbc-basic: contains '-path ../bbc-basic', so it assumes that it is
  executed in an implementation directory (even if not necessary its
  own).

* impls/matlab/run already seems to assume that is is executed in its
  directory.

It also fixes the execution of $path_with_spaces/impls/vimscript/run.

Take the opportunity to change most shebangs from '/usr/bin/env bash'
to 'bin/sh' because the latter is more portable, and more efficient
when both actually differ.

Also trigger all optional shell errors.
---
 impls/ada.2/run                 |  3 ++-
 impls/ada/run                   |  5 +++--
 impls/awk/run                   |  5 +++--
 impls/bash/run                  |  5 +++--
 impls/basic/run                 |  6 +++++-
 impls/bbc-basic/run             |  5 +++--
 impls/c.2/run                   |  3 ++-
 impls/c/run                     |  5 +++--
 impls/chuck/run                 |  8 +++++---
 impls/clojure/run               |  9 +++++----
 impls/coffee/run                |  5 +++--
 impls/common-lisp/run           |  5 +++--
 impls/cpp/run                   |  5 +++--
 impls/crystal/run               |  3 ++-
 impls/cs/run                    |  5 +++--
 impls/d/run                     |  5 +++--
 impls/dart/run                  |  5 +++--
 impls/elisp/run                 |  6 +++---
 impls/elixir/run                |  4 ++--
 impls/elm/run                   |  5 +++--
 impls/erlang/run                |  5 +++--
 impls/es6/run                   |  5 +++--
 impls/factor/run                |  5 +++--
 impls/fantom/run                |  5 +++--
 impls/fennel/run                |  6 +++---
 impls/forth/run                 |  5 +++--
 impls/fsharp/run                |  5 +++--
 impls/gnu-smalltalk/run         |  5 +++--
 impls/go/run                    |  5 +++--
 impls/groovy/run                |  5 +++--
 impls/guile/run                 |  5 +++--
 impls/hare/run                  |  6 +++---
 impls/haskell/run               |  3 ++-
 impls/haxe/run                  | 11 ++++++-----
 impls/hy/run                    |  5 +++--
 impls/io/run                    |  6 +++---
 impls/janet/run                 |  3 ++-
 impls/java-truffle/run          |  3 ++-
 impls/js/run                    |  5 +++--
 impls/julia/run                 |  5 +++--
 impls/kotlin/run                |  5 +++--
 impls/latex3/run                |  1 -
 impls/livescript/run            |  5 +++--
 impls/logo/run                  |  5 +++--
 impls/lua/run                   |  5 +++--
 impls/make/run                  |  5 +++--
 impls/mal/run                   |  9 ++++++---
 impls/matlab/run                |  1 +
 impls/miniMAL/run               |  6 +++---
 impls/nasm/run                  |  6 +++---
 impls/nim/run                   |  3 ++-
 impls/objc/run                  |  5 +++--
 impls/objpascal/run             |  5 +++--
 impls/ocaml/run                 |  3 ++-
 impls/perl/run                  |  5 +++--
 impls/perl6/run                 |  5 +++--
 impls/php/run                   |  5 +++--
 impls/php/tests/stepA_mal.mal   |  2 +-
 impls/picolisp/run              |  5 +++--
 impls/pike/run                  |  5 +++--
 impls/powershell/run            |  3 ++-
 impls/prolog/run                |  5 +++--
 impls/ps/run                    |  5 +++--
 impls/purs/run                  |  7 ++++++-
 impls/python2/run               |  3 ++-
 impls/python3/run               |  3 ++-
 impls/r/run                     |  5 +++--
 impls/racket/run                |  5 +++--
 impls/rexx/run                  |  3 ++-
 impls/rpython/run               |  5 +++--
 impls/ruby.2/run                |  5 +++--
 impls/ruby/run                  |  5 +++--
 impls/rust/run                  |  3 ++-
 impls/scala/run                 |  5 +++--
 impls/scheme/run                | 18 +++++++++---------
 impls/skew/run                  |  5 +++--
 impls/sml/run                   |  5 +++--
 impls/swift3/run                |  5 +++--
 impls/swift4/run                |  5 +++--
 impls/swift6/run                |  3 ++-
 impls/tcl/run                   |  5 +++--
 impls/tests/run_argv_test.sh    |  5 +++--
 impls/ts/run                    |  5 +++--
 impls/vala/run                  |  5 +++--
 impls/vb/run                    |  5 +++--
 impls/vbs/run                   |  5 +++--
 impls/vhdl/run                  |  7 +++----
 impls/vimscript/run             |  8 ++++----
 impls/wasm/run                  | 15 ++++++++-------
 impls/wren/run                  |  5 +++--
 impls/yorick/run                |  6 +++---
 impls/yorick/step1_read_print.i |  1 -
 impls/yorick/step2_eval.i       |  1 -
 impls/yorick/step3_env.i        |  1 -
 impls/yorick/step4_if_fn_do.i   |  1 -
 impls/yorick/step5_tco.i        |  1 -
 impls/yorick/step6_file.i       |  1 -
 impls/yorick/step7_quote.i      |  1 -
 impls/yorick/step8_macros.i     |  1 -
 impls/yorick/step9_try.i        |  1 -
 impls/yorick/stepA_mal.i        |  1 -
 impls/zig/run                   |  3 ++-
 process/guide.md                | 23 ++++++++++++++++++-----
 103 files changed, 298 insertions(+), 208 deletions(-)
 mode change 100644 => 100755 impls/vbs/run

diff --git a/impls/ada.2/run b/impls/ada.2/run
index 57693e8022..5ffd062744 100755
--- a/impls/ada.2/run
+++ b/impls/ada.2/run
@@ -1,2 +1,3 @@
 #!/bin/sh
-exec $(dirname $0)/${STEP:-stepA_mal} "$@"
+set -Cefu
+exec ./${STEP:-stepA_mal} "$@"
diff --git a/impls/ada/run b/impls/ada/run
index 6e11defbfb..5ffd062744 100755
--- a/impls/ada/run
+++ b/impls/ada/run
@@ -1,2 +1,3 @@
-#!/usr/bin/env bash
-exec $(dirname $0)/${STEP:-stepA_mal} "$@"
+#!/bin/sh
+set -Cefu
+exec ./${STEP:-stepA_mal} "$@"
diff --git a/impls/awk/run b/impls/awk/run
index c3cfdf6044..f0a9f48c35 100755
--- a/impls/awk/run
+++ b/impls/awk/run
@@ -1,2 +1,3 @@
-#!/usr/bin/env bash
-exec awk -f $(dirname $0)/${STEP:-stepA_mal}.awk "$@"
+#!/bin/sh
+set -Cefu
+exec awk -f ${STEP:-stepA_mal}.awk "$@"
diff --git a/impls/bash/run b/impls/bash/run
index 29e282a6af..5ada142c2f 100755
--- a/impls/bash/run
+++ b/impls/bash/run
@@ -1,2 +1,3 @@
-#!/usr/bin/env bash
-exec bash $(dirname $0)/${STEP:-stepA_mal}.sh "$@"
+#!/bin/sh
+set -Cefu
+exec bash ${STEP:-stepA_mal}.sh "$@"
diff --git a/impls/basic/run b/impls/basic/run
index 82b00367bb..84d80b9123 100755
--- a/impls/basic/run
+++ b/impls/basic/run
@@ -1,5 +1,9 @@
 #!/usr/bin/env bash
-cd $(dirname $0)
+
+# #!/bin/sh
+# set -efu
+# lets the step0 test for qbasic times out.
+
 {
     printf '(def! -*ARGS*- (list'
     [ $# = 0 ] || printf ' "%s"' "$@"
diff --git a/impls/bbc-basic/run b/impls/bbc-basic/run
index 1e3b0523a0..8701b18cf7 100755
--- a/impls/bbc-basic/run
+++ b/impls/bbc-basic/run
@@ -1,3 +1,4 @@
-#!/usr/bin/env bash
+#!/bin/sh
+set -Cefu
 exec "${BRANDY:-sbrandy}" -size 1024k \
-    -path ../bbc-basic -quit $(dirname $0)/${STEP:-stepA_mal}.bas "$@"
+    -quit ${STEP:-stepA_mal}.bas "$@"
diff --git a/impls/c.2/run b/impls/c.2/run
index 57693e8022..5ffd062744 100755
--- a/impls/c.2/run
+++ b/impls/c.2/run
@@ -1,2 +1,3 @@
 #!/bin/sh
-exec $(dirname $0)/${STEP:-stepA_mal} "$@"
+set -Cefu
+exec ./${STEP:-stepA_mal} "$@"
diff --git a/impls/c/run b/impls/c/run
index 6e11defbfb..5ffd062744 100755
--- a/impls/c/run
+++ b/impls/c/run
@@ -1,2 +1,3 @@
-#!/usr/bin/env bash
-exec $(dirname $0)/${STEP:-stepA_mal} "$@"
+#!/bin/sh
+set -Cefu
+exec ./${STEP:-stepA_mal} "$@"
diff --git a/impls/chuck/run b/impls/chuck/run
index 7f7e1e5d97..9375e4d69b 100755
--- a/impls/chuck/run
+++ b/impls/chuck/run
@@ -1,5 +1,6 @@
-#!/usr/bin/env bash
-step=$(dirname $0)/${STEP:-stepA_mal}.ck
+#!/bin/sh
+set -Ceu
+step=${STEP:-stepA_mal}.ck
 
 regex_chugin=${REGEX_CHUGIN:-/usr/local/lib/chuck/1.5.2.5/RegEx.chug}
 if [ ! -f "$regex_chugin" ]; then
@@ -7,7 +8,8 @@ if [ ! -f "$regex_chugin" ]; then
     exit 1
 fi
 
-imports=$(sed -n "s|^ *// *@import *|$(dirname $0)/|p" $step)
+# The globs will be expanded in the exec line.
+imports=$(sed -n "s|^ *// *@import *||p" $step)
 
 separator=$(printf '\a')
 for x; do
diff --git a/impls/clojure/run b/impls/clojure/run
index 1005d79779..0c188c559a 100755
--- a/impls/clojure/run
+++ b/impls/clojure/run
@@ -1,9 +1,10 @@
-#!/usr/bin/env bash
-export PATH="$PATH:$(dirname $0)/node_modules/.bin"
+#!/bin/sh
+set -Cefu
+export PATH="$PATH:node_modules/.bin"
 STEP=${STEP:-stepA_mal}
 case ${clojure_MODE:-clj} in
-    cljs) exec lumo -c $(dirname $0)/src -m mal.${STEP//_/-} "$@" ;;
-    clj)  exec java -jar $(dirname $0)/target/$STEP.jar "$@" ;;
+    cljs) exec lumo -c src -m mal.$(echo $STEP | tr _ -) "$@" ;;
+    clj)  exec java -jar target/$STEP.jar "$@" ;;
 esac
 echo "Invalid clojure_MODE: $clojure_MODE"
 exit 1
diff --git a/impls/coffee/run b/impls/coffee/run
index 72d7c2817d..58f481b9ec 100755
--- a/impls/coffee/run
+++ b/impls/coffee/run
@@ -1,2 +1,3 @@
-#!/usr/bin/env bash
-exec coffee $(dirname $0)/${STEP:-stepA_mal}.coffee "$@"
+#!/bin/sh
+set -Cefu
+exec coffee ${STEP:-stepA_mal}.coffee "$@"
diff --git a/impls/common-lisp/run b/impls/common-lisp/run
index 6e11defbfb..5ffd062744 100755
--- a/impls/common-lisp/run
+++ b/impls/common-lisp/run
@@ -1,2 +1,3 @@
-#!/usr/bin/env bash
-exec $(dirname $0)/${STEP:-stepA_mal} "$@"
+#!/bin/sh
+set -Cefu
+exec ./${STEP:-stepA_mal} "$@"
diff --git a/impls/cpp/run b/impls/cpp/run
index 6e11defbfb..5ffd062744 100755
--- a/impls/cpp/run
+++ b/impls/cpp/run
@@ -1,2 +1,3 @@
-#!/usr/bin/env bash
-exec $(dirname $0)/${STEP:-stepA_mal} "$@"
+#!/bin/sh
+set -Cefu
+exec ./${STEP:-stepA_mal} "$@"
diff --git a/impls/crystal/run b/impls/crystal/run
index 3d36605e03..bf24a176db 100755
--- a/impls/crystal/run
+++ b/impls/crystal/run
@@ -1,2 +1,3 @@
 #!/bin/sh
-exec $(dirname $0)/bin/${STEP:-stepA_mal} "$@"
+set -Cefu
+exec bin/${STEP:-stepA_mal} "$@"
diff --git a/impls/cs/run b/impls/cs/run
index 91beef2d69..8ea6fdbea1 100755
--- a/impls/cs/run
+++ b/impls/cs/run
@@ -1,2 +1,3 @@
-#!/usr/bin/env bash
-exec mono $(dirname $0)/${STEP:-stepA_mal}.exe ${RAW:+--raw} "$@"
+#!/bin/sh
+set -Cefu
+exec mono ${STEP:-stepA_mal}.exe ${RAW:+--raw} "$@"
diff --git a/impls/d/run b/impls/d/run
index 6e11defbfb..5ffd062744 100755
--- a/impls/d/run
+++ b/impls/d/run
@@ -1,2 +1,3 @@
-#!/usr/bin/env bash
-exec $(dirname $0)/${STEP:-stepA_mal} "$@"
+#!/bin/sh
+set -Cefu
+exec ./${STEP:-stepA_mal} "$@"
diff --git a/impls/dart/run b/impls/dart/run
index 948a2a45a7..d8320472de 100755
--- a/impls/dart/run
+++ b/impls/dart/run
@@ -1,2 +1,3 @@
-#!/usr/bin/env bash
-exec dart --checked $(dirname $0)/${STEP:-stepA_mal}.dart "$@"
+#!/bin/sh
+set -Cefu
+exec dart --checked ${STEP:-stepA_mal}.dart "$@"
diff --git a/impls/elisp/run b/impls/elisp/run
index f14aebb10a..16aaeb34c5 100755
--- a/impls/elisp/run
+++ b/impls/elisp/run
@@ -1,5 +1,5 @@
 #!/bin/sh
-dir=$(dirname $0)
-exec emacs -Q --batch -L $dir \
+set -Cefu
+exec emacs -Q --batch -L . \
      --eval "(setq text-quoting-style 'straight)" \
-     --load $dir/${STEP:-stepA_mal}.elc "$@"
+     --load ${STEP:-stepA_mal}.elc "$@"
diff --git a/impls/elixir/run b/impls/elixir/run
index 191a56a45e..8c4f3f8eeb 100755
--- a/impls/elixir/run
+++ b/impls/elixir/run
@@ -1,3 +1,3 @@
-#!/usr/bin/env bash
-cd $(dirname $0)
+#!/bin/sh
+set -Cefu
 exec mix ${STEP:-stepA_mal} "$@"
diff --git a/impls/elm/run b/impls/elm/run
index 4cf42af657..7235b16b18 100755
--- a/impls/elm/run
+++ b/impls/elm/run
@@ -1,2 +1,3 @@
-#!/usr/bin/env bash
-exec node $(dirname $0)/bootstrap.js ${STEP:-stepA_mal} "$@"
+#!/bin/sh
+set -Cefu
+exec node bootstrap.js ${STEP:-stepA_mal} "$@"
diff --git a/impls/erlang/run b/impls/erlang/run
index 6e11defbfb..5ffd062744 100755
--- a/impls/erlang/run
+++ b/impls/erlang/run
@@ -1,2 +1,3 @@
-#!/usr/bin/env bash
-exec $(dirname $0)/${STEP:-stepA_mal} "$@"
+#!/bin/sh
+set -Cefu
+exec ./${STEP:-stepA_mal} "$@"
diff --git a/impls/es6/run b/impls/es6/run
index b71faee4cd..1c8b71b919 100755
--- a/impls/es6/run
+++ b/impls/es6/run
@@ -1,2 +1,3 @@
-#!/usr/bin/env bash
-exec node $(dirname $0)/${STEP:-stepA_mal}.mjs "$@"
+#!/bin/sh
+set -Cefu
+exec node ${STEP:-stepA_mal}.mjs "$@"
diff --git a/impls/factor/run b/impls/factor/run
index 812e8c3c01..b2e0210719 100755
--- a/impls/factor/run
+++ b/impls/factor/run
@@ -1,3 +1,4 @@
-#!/usr/bin/env bash
+#!/bin/sh
+set -Cefu
 step=${STEP:-stepA_mal}
-exec factor $(dirname $0)/$step/$step.factor "$@"
+exec factor $step/$step.factor "$@"
diff --git a/impls/fantom/run b/impls/fantom/run
index b0b70cf57b..72c94f7416 100755
--- a/impls/fantom/run
+++ b/impls/fantom/run
@@ -1,4 +1,5 @@
-#!/usr/bin/env bash
+#!/bin/sh
+set -Cefu
 export FAN_ENV=util::PathEnv
-export FAN_ENV_PATH="$(dirname $0)"
+export FAN_ENV_PATH=.
 exec fan ${STEP:-stepA_mal} "$@"
diff --git a/impls/fennel/run b/impls/fennel/run
index 904ff718f6..12cbae82c3 100755
--- a/impls/fennel/run
+++ b/impls/fennel/run
@@ -1,3 +1,3 @@
-#!/usr/bin/env bash
-
-exec fennel $(dirname $0)/${STEP:-stepA_mal}.fnl "$@"
+#!/bin/sh
+set -Cefu
+exec fennel ${STEP:-stepA_mal}.fnl "$@"
diff --git a/impls/forth/run b/impls/forth/run
index 9d9b6d77f1..3290045678 100755
--- a/impls/forth/run
+++ b/impls/forth/run
@@ -1,2 +1,3 @@
-#!/usr/bin/env bash
-exec gforth $(dirname $0)/${STEP:-stepA_mal}.fs "$@"
+#!/bin/sh
+set -Cefu
+exec gforth ${STEP:-stepA_mal}.fs "$@"
diff --git a/impls/fsharp/run b/impls/fsharp/run
index 91beef2d69..8ea6fdbea1 100755
--- a/impls/fsharp/run
+++ b/impls/fsharp/run
@@ -1,2 +1,3 @@
-#!/usr/bin/env bash
-exec mono $(dirname $0)/${STEP:-stepA_mal}.exe ${RAW:+--raw} "$@"
+#!/bin/sh
+set -Cefu
+exec mono ${STEP:-stepA_mal}.exe ${RAW:+--raw} "$@"
diff --git a/impls/gnu-smalltalk/run b/impls/gnu-smalltalk/run
index 9e87a265dd..746651207f 100755
--- a/impls/gnu-smalltalk/run
+++ b/impls/gnu-smalltalk/run
@@ -1,2 +1,3 @@
-#!/usr/bin/env bash
-exec gst -f $(dirname $0)/${STEP:-stepA_mal}.st "$@"
+#!/bin/sh
+set -Cefu
+exec gst -f ${STEP:-stepA_mal}.st "$@"
diff --git a/impls/go/run b/impls/go/run
index 6e11defbfb..5ffd062744 100755
--- a/impls/go/run
+++ b/impls/go/run
@@ -1,2 +1,3 @@
-#!/usr/bin/env bash
-exec $(dirname $0)/${STEP:-stepA_mal} "$@"
+#!/bin/sh
+set -Cefu
+exec ./${STEP:-stepA_mal} "$@"
diff --git a/impls/groovy/run b/impls/groovy/run
index fff2753561..9733f7c8a5 100755
--- a/impls/groovy/run
+++ b/impls/groovy/run
@@ -1,2 +1,3 @@
-#!/usr/bin/env bash
-exec groovy $(dirname $0)/${STEP:-stepA_mal}.groovy "$@"
+#!/bin/sh
+set -Cefu
+exec groovy ${STEP:-stepA_mal}.groovy "$@"
diff --git a/impls/guile/run b/impls/guile/run
index 0e133613f4..747d2c6932 100755
--- a/impls/guile/run
+++ b/impls/guile/run
@@ -1,3 +1,4 @@
-#!/usr/bin/env bash
+#!/bin/sh
+set -Cefu
 # XDG_CACHE_HOME is where guile stores the compiled files
-XDG_CACHE_HOME=.cache/ exec guile -L $(dirname $0) $(dirname $0)/${STEP:-stepA_mal}.scm "$@"
+XDG_CACHE_HOME=.cache/ exec guile -L . ${STEP:-stepA_mal}.scm "$@"
diff --git a/impls/hare/run b/impls/hare/run
index 81319040b2..5ffd062744 100755
--- a/impls/hare/run
+++ b/impls/hare/run
@@ -1,3 +1,3 @@
-#!/usr/bin/env bash
-
-exec $(dirname $0)/${STEP:-stepA_mal} "$@"
+#!/bin/sh
+set -Cefu
+exec ./${STEP:-stepA_mal} "$@"
diff --git a/impls/haskell/run b/impls/haskell/run
index 57693e8022..5ffd062744 100755
--- a/impls/haskell/run
+++ b/impls/haskell/run
@@ -1,2 +1,3 @@
 #!/bin/sh
-exec $(dirname $0)/${STEP:-stepA_mal} "$@"
+set -Cefu
+exec ./${STEP:-stepA_mal} "$@"
diff --git a/impls/haxe/run b/impls/haxe/run
index f94b1e557a..fdd0476b6a 100755
--- a/impls/haxe/run
+++ b/impls/haxe/run
@@ -1,8 +1,9 @@
-#!/usr/bin/env bash
+#!/bin/sh
+set -Cefu
 case ${haxe_MODE:-neko} in
-    neko)   exec neko    $(dirname $0)/${STEP:-stepA_mal}.n   "$@" ;;
-    python) exec python3 $(dirname $0)/${STEP:-stepA_mal}.py  "$@" ;;
-    js)     exec node    $(dirname $0)/${STEP:-stepA_mal}.js  "$@" ;;
-    cpp)    exec         $(dirname $0)/cpp/${STEP:-stepA_mal} "$@" ;;
+    neko)   exec neko    ${STEP:-stepA_mal}.n   "$@" ;;
+    python) exec python3 ${STEP:-stepA_mal}.py  "$@" ;;
+    js)     exec node    ${STEP:-stepA_mal}.js  "$@" ;;
+    cpp)    exec         cpp/${STEP:-stepA_mal} "$@" ;;
     *) echo "Invalid haxe_MODE: $haxe_MODE"; exit 2 ;;
 esac
diff --git a/impls/hy/run b/impls/hy/run
index efe4b22686..777d500345 100755
--- a/impls/hy/run
+++ b/impls/hy/run
@@ -1,2 +1,3 @@
-#!/usr/bin/env bash
-exec hy $(dirname $0)/${STEP:-stepA_mal}.hy "$@"
+#!/bin/sh
+set -Cefu
+exec hy ${STEP:-stepA_mal}.hy "$@"
diff --git a/impls/io/run b/impls/io/run
index d49d10a227..6d84acab3b 100755
--- a/impls/io/run
+++ b/impls/io/run
@@ -1,3 +1,3 @@
-#!/usr/bin/env bash
-
-io $(dirname $0)/${STEP:-stepA_mal}.io "$@"
+#!/bin/sh
+set -Cefu
+exec io ${STEP:-stepA_mal}.io "$@"
diff --git a/impls/janet/run b/impls/janet/run
index e06e39a8d4..59c0c1b628 100755
--- a/impls/janet/run
+++ b/impls/janet/run
@@ -1,2 +1,3 @@
 #!/bin/sh
-exec janet $(dirname $0)/${STEP:-stepA_mal}.janet "$@"
+set -Cefu
+exec janet ${STEP:-stepA_mal}.janet "$@"
diff --git a/impls/java-truffle/run b/impls/java-truffle/run
index c5ca27135f..5e6271cbe4 100755
--- a/impls/java-truffle/run
+++ b/impls/java-truffle/run
@@ -1,4 +1,5 @@
-#!/usr/bin/env bash
+#!/bin/sh
+set -Cefu
 
 CP=$(gradle -q --console plain printClasspath)
 
diff --git a/impls/js/run b/impls/js/run
index 893cbb59c7..d1135e76d4 100755
--- a/impls/js/run
+++ b/impls/js/run
@@ -1,2 +1,3 @@
-#!/usr/bin/env bash
-exec node $(dirname $0)/${STEP:-stepA_mal}.js "$@"
+#!/bin/sh
+set -Cefu
+exec node ${STEP:-stepA_mal}.js "$@"
diff --git a/impls/julia/run b/impls/julia/run
index 5791967a12..3a08886fca 100755
--- a/impls/julia/run
+++ b/impls/julia/run
@@ -1,2 +1,3 @@
-#!/usr/bin/env bash
-exec julia $(dirname $0)/${STEP:-stepA_mal}.jl "$@"
+#!/bin/sh
+set -Cefu
+exec julia ${STEP:-stepA_mal}.jl "$@"
diff --git a/impls/kotlin/run b/impls/kotlin/run
index 0dce7b02a0..f77cf44639 100755
--- a/impls/kotlin/run
+++ b/impls/kotlin/run
@@ -1,2 +1,3 @@
-#!/usr/bin/env bash
-exec java -jar $(dirname $0)/${STEP:-stepA_mal}.jar "$@"
+#!/bin/sh
+set -Cefu
+exec java -jar ${STEP:-stepA_mal}.jar "$@"
diff --git a/impls/latex3/run b/impls/latex3/run
index 7a05291e20..c8965f8caf 100755
--- a/impls/latex3/run
+++ b/impls/latex3/run
@@ -2,7 +2,6 @@
 set -Cefu
 
 # LaTeX creates temporary files in the current directory.
-cd $(dirname $0)
 
 # There is no way to directly provide command line arguments to LaTeX,
 # use an intermediate file.
diff --git a/impls/livescript/run b/impls/livescript/run
index 893cbb59c7..d1135e76d4 100755
--- a/impls/livescript/run
+++ b/impls/livescript/run
@@ -1,2 +1,3 @@
-#!/usr/bin/env bash
-exec node $(dirname $0)/${STEP:-stepA_mal}.js "$@"
+#!/bin/sh
+set -Cefu
+exec node ${STEP:-stepA_mal}.js "$@"
diff --git a/impls/logo/run b/impls/logo/run
index 065ff2b5d5..422aa8fc40 100755
--- a/impls/logo/run
+++ b/impls/logo/run
@@ -1,2 +1,3 @@
-#!/usr/bin/env bash
-exec ucblogo $(dirname $0)/${STEP:-stepA_mal}.lg - "$@"
+#!/bin/sh
+set -Cefu
+exec ucblogo ${STEP:-stepA_mal}.lg - "$@"
diff --git a/impls/lua/run b/impls/lua/run
index 87847a41e6..78595ba01f 100755
--- a/impls/lua/run
+++ b/impls/lua/run
@@ -1,2 +1,3 @@
-#!/usr/bin/env bash
-exec lua $(dirname $0)/${STEP:-stepA_mal}.lua "$@"
+#!/bin/sh
+set -Cefu
+exec lua ${STEP:-stepA_mal}.lua "$@"
diff --git a/impls/make/run b/impls/make/run
index 9a10a4e51d..bfbcc4447e 100755
--- a/impls/make/run
+++ b/impls/make/run
@@ -1,2 +1,3 @@
-#!/usr/bin/env bash
-exec make --no-print-directory -f $(dirname $0)/${STEP:-stepA_mal}.mk "$@"
+#!/bin/sh
+set -Cefu
+exec make --no-print-directory -f ${STEP:-stepA_mal}.mk "$@"
diff --git a/impls/mal/run b/impls/mal/run
index 5b48bd55bb..f9ac1907bc 100755
--- a/impls/mal/run
+++ b/impls/mal/run
@@ -1,12 +1,15 @@
-#!/usr/bin/env bash
+#!/bin/sh
+set -Cefu
 MAL_FILE=../mal/${STEP:-stepA_mal}.mal
 export STEP=stepA_mal # force MAL_IMPL to use stepA
 impl=${MAL_IMPL:-js}
 case $impl in
     *-mal)
-        exec ../${impl%-mal}/run ../mal/stepA_mal.mal $MAL_FILE "$@"
+        cd ../${impl%-mal}
+        exec ./run ../mal/stepA_mal.mal $MAL_FILE "$@"
         ;;
     *)
-        exec ../$impl/run $MAL_FILE "$@"
+        cd ../$impl
+        exec ./run $MAL_FILE "$@"
         ;;
 esac
diff --git a/impls/matlab/run b/impls/matlab/run
index 6181b298e0..34d12fa2ba 100755
--- a/impls/matlab/run
+++ b/impls/matlab/run
@@ -1,4 +1,5 @@
 #!/bin/sh
+set -Cefu
 
 for x; do
     args="${args:+$args, }'$x'"
diff --git a/impls/miniMAL/run b/impls/miniMAL/run
index df66bc329c..824b708851 100755
--- a/impls/miniMAL/run
+++ b/impls/miniMAL/run
@@ -1,3 +1,3 @@
-#!/usr/bin/env bash
-cd $(dirname $0)
-exec miniMAL ./${STEP:-stepA_mal}.json "$@"
+#!/bin/sh
+set -Cefu
+exec miniMAL ${STEP:-stepA_mal}.json "$@"
diff --git a/impls/nasm/run b/impls/nasm/run
index 7933a7939f..5ffd062744 100755
--- a/impls/nasm/run
+++ b/impls/nasm/run
@@ -1,3 +1,3 @@
-#!/usr/bin/env bash
-exec $(dirname $0)/${STEP:-stepA_mal} "$@"
-
+#!/bin/sh
+set -Cefu
+exec ./${STEP:-stepA_mal} "$@"
diff --git a/impls/nim/run b/impls/nim/run
index 57693e8022..5ffd062744 100755
--- a/impls/nim/run
+++ b/impls/nim/run
@@ -1,2 +1,3 @@
 #!/bin/sh
-exec $(dirname $0)/${STEP:-stepA_mal} "$@"
+set -Cefu
+exec ./${STEP:-stepA_mal} "$@"
diff --git a/impls/objc/run b/impls/objc/run
index 6e11defbfb..5ffd062744 100755
--- a/impls/objc/run
+++ b/impls/objc/run
@@ -1,2 +1,3 @@
-#!/usr/bin/env bash
-exec $(dirname $0)/${STEP:-stepA_mal} "$@"
+#!/bin/sh
+set -Cefu
+exec ./${STEP:-stepA_mal} "$@"
diff --git a/impls/objpascal/run b/impls/objpascal/run
index 6e11defbfb..5ffd062744 100755
--- a/impls/objpascal/run
+++ b/impls/objpascal/run
@@ -1,2 +1,3 @@
-#!/usr/bin/env bash
-exec $(dirname $0)/${STEP:-stepA_mal} "$@"
+#!/bin/sh
+set -Cefu
+exec ./${STEP:-stepA_mal} "$@"
diff --git a/impls/ocaml/run b/impls/ocaml/run
index 57693e8022..5ffd062744 100755
--- a/impls/ocaml/run
+++ b/impls/ocaml/run
@@ -1,2 +1,3 @@
 #!/bin/sh
-exec $(dirname $0)/${STEP:-stepA_mal} "$@"
+set -Cefu
+exec ./${STEP:-stepA_mal} "$@"
diff --git a/impls/perl/run b/impls/perl/run
index a388a0c3ce..88118dc06b 100755
--- a/impls/perl/run
+++ b/impls/perl/run
@@ -1,2 +1,3 @@
-#!/usr/bin/env bash
-exec perl $(dirname $0)/${STEP:-stepA_mal}.pl ${RAW:+--raw} "$@"
+#!/bin/sh
+set -Cefu
+exec perl ${STEP:-stepA_mal}.pl ${RAW:+--raw} "$@"
diff --git a/impls/perl6/run b/impls/perl6/run
index 8a58ac8a01..8d8e369eed 100755
--- a/impls/perl6/run
+++ b/impls/perl6/run
@@ -1,2 +1,3 @@
-#!/usr/bin/env bash
-exec perl6 $(dirname $0)/${STEP:-stepA_mal}.pl "$@"
+#!/bin/sh
+set -Cefu
+exec perl6 ${STEP:-stepA_mal}.pl "$@"
diff --git a/impls/php/run b/impls/php/run
index ef22b62eb3..d2f262bc2b 100755
--- a/impls/php/run
+++ b/impls/php/run
@@ -1,2 +1,3 @@
-#!/usr/bin/env bash
-exec php $(dirname $0)/${STEP:-stepA_mal}.php "$@"
+#!/bin/sh
+set -Cefu
+exec php ${STEP:-stepA_mal}.php "$@"
diff --git a/impls/php/tests/stepA_mal.mal b/impls/php/tests/stepA_mal.mal
index de459cdbcf..3a873c0440 100644
--- a/impls/php/tests/stepA_mal.mal
+++ b/impls/php/tests/stepA_mal.mal
@@ -37,7 +37,7 @@
 ;; testing superglobal variable access
 
 (get php/_SERVER "PHP_SELF")
-;=>"../php/stepA_mal.php"
+;=>"stepA_mal.php"
 
 ;; testing PHP constants access
 
diff --git a/impls/picolisp/run b/impls/picolisp/run
index a9f757b2d9..7e5ffa8b30 100755
--- a/impls/picolisp/run
+++ b/impls/picolisp/run
@@ -1,2 +1,3 @@
-#!/usr/bin/env bash
-exec pil $(dirname $0)/${STEP:-stepA_mal}.l - "$@"
+#!/bin/sh
+set -Cefu
+exec pil ${STEP:-stepA_mal}.l - "$@"
diff --git a/impls/pike/run b/impls/pike/run
index 8b74b25265..bb8b2b35ee 100755
--- a/impls/pike/run
+++ b/impls/pike/run
@@ -1,2 +1,3 @@
-#!/usr/bin/env bash
-exec pike $(dirname $0)/${STEP:-stepA_mal}.pike "$@"
+#!/bin/sh
+set -Cefu
+exec pike ${STEP:-stepA_mal}.pike "$@"
diff --git a/impls/powershell/run b/impls/powershell/run
index 0927bcdcea..4687eac282 100755
--- a/impls/powershell/run
+++ b/impls/powershell/run
@@ -1,2 +1,3 @@
 #!/bin/sh
-exec powershell $(dirname $0)/${STEP:-stepA_mal}.ps1 "$@"
+set -Cefu
+exec powershell ./${STEP:-stepA_mal}.ps1 "$@"
diff --git a/impls/prolog/run b/impls/prolog/run
index 908d180b8b..fa8ca18ff3 100755
--- a/impls/prolog/run
+++ b/impls/prolog/run
@@ -1,2 +1,3 @@
-#!/usr/bin/env bash
-exec swipl $(dirname $0)/${STEP:-stepA_mal}.pl "$@"
+#!/bin/sh
+set -Cefu
+exec swipl ${STEP:-stepA_mal}.pl "$@"
diff --git a/impls/ps/run b/impls/ps/run
index dde80e1f66..2887396e2e 100755
--- a/impls/ps/run
+++ b/impls/ps/run
@@ -1,2 +1,3 @@
-#!/usr/bin/env bash
-exec gs -q -I$(dirname $0) -dNOSAFER -dNODISPLAY -- $(dirname $0)/${STEP:-stepA_mal}.ps "$@"
+#!/bin/sh
+set -Cefu
+exec gs -q -I. -dNOSAFER -dNODISPLAY -- ${STEP:-stepA_mal}.ps "$@"
diff --git a/impls/purs/run b/impls/purs/run
index 893cbb59c7..1b12317b7e 100755
--- a/impls/purs/run
+++ b/impls/purs/run
@@ -1,2 +1,7 @@
 #!/usr/bin/env bash
-exec node $(dirname $0)/${STEP:-stepA_mal}.js "$@"
+
+# #!/bin/sh
+# set -efu
+# breaks the self hosted test for step0 with an IO exception.
+
+exec node ${STEP:-stepA_mal}.js "$@"
diff --git a/impls/python2/run b/impls/python2/run
index 2c41196a13..69c9dc7644 100755
--- a/impls/python2/run
+++ b/impls/python2/run
@@ -1,2 +1,3 @@
 #!/bin/sh
-exec python2 $(dirname $0)/${STEP:-stepA_mal}.py "$@"
+set -Cefu
+exec python2 ${STEP:-stepA_mal}.py "$@"
diff --git a/impls/python3/run b/impls/python3/run
index 9b7b01bfba..e57219fcae 100755
--- a/impls/python3/run
+++ b/impls/python3/run
@@ -1,2 +1,3 @@
 #!/bin/sh
-exec python3 $(dirname $0)/${STEP:-stepA_mal}.py "$@"
+set -Cefu
+exec python3 ${STEP:-stepA_mal}.py "$@"
diff --git a/impls/r/run b/impls/r/run
index 9675392139..3d8166379b 100755
--- a/impls/r/run
+++ b/impls/r/run
@@ -1,2 +1,3 @@
-#!/usr/bin/env bash
-exec Rscript $(dirname $0)/${STEP:-stepA_mal}.r "$@"
+#!/bin/sh
+set -Cefu
+exec Rscript ${STEP:-stepA_mal}.r "$@"
diff --git a/impls/racket/run b/impls/racket/run
index 07cc20aa3f..72658cfba8 100755
--- a/impls/racket/run
+++ b/impls/racket/run
@@ -1,2 +1,3 @@
-#!/usr/bin/env bash
-exec racket $(dirname $0)/${STEP:-stepA_mal}.rkt "$@"
+#!/bin/sh
+set -Cefu
+exec racket ${STEP:-stepA_mal}.rkt "$@"
diff --git a/impls/rexx/run b/impls/rexx/run
index a38c60a0c6..307605eaae 100755
--- a/impls/rexx/run
+++ b/impls/rexx/run
@@ -1,2 +1,3 @@
 #!/bin/sh
-exec rexx -a $(dirname $0)/${STEP:-stepA_mal}.rexxpp "$@"
+set -Cefu
+exec rexx -a ${STEP:-stepA_mal}.rexxpp "$@"
diff --git a/impls/rpython/run b/impls/rpython/run
index 6e11defbfb..5ffd062744 100755
--- a/impls/rpython/run
+++ b/impls/rpython/run
@@ -1,2 +1,3 @@
-#!/usr/bin/env bash
-exec $(dirname $0)/${STEP:-stepA_mal} "$@"
+#!/bin/sh
+set -Cefu
+exec ./${STEP:-stepA_mal} "$@"
diff --git a/impls/ruby.2/run b/impls/ruby.2/run
index c1acbcbbfb..af3ef3ab4e 100755
--- a/impls/ruby.2/run
+++ b/impls/ruby.2/run
@@ -1,2 +1,3 @@
-#!/usr/bin/env bash
-exec ruby $(dirname $0)/${STEP:-stepA_mal}.rb "$@"
+#!/bin/sh
+set -Cefu
+exec ruby ${STEP:-stepA_mal}.rb "$@"
diff --git a/impls/ruby/run b/impls/ruby/run
index c1acbcbbfb..af3ef3ab4e 100755
--- a/impls/ruby/run
+++ b/impls/ruby/run
@@ -1,2 +1,3 @@
-#!/usr/bin/env bash
-exec ruby $(dirname $0)/${STEP:-stepA_mal}.rb "$@"
+#!/bin/sh
+set -Cefu
+exec ruby ${STEP:-stepA_mal}.rb "$@"
diff --git a/impls/rust/run b/impls/rust/run
index a86855ad8d..46e9ab2269 100755
--- a/impls/rust/run
+++ b/impls/rust/run
@@ -1,2 +1,3 @@
 #!/bin/sh
-exec $(dirname $0)/target/release/${STEP:-stepA_mal} "$@"
+set -Cefu
+exec target/release/${STEP:-stepA_mal} "$@"
diff --git a/impls/scala/run b/impls/scala/run
index aec8710d86..57b25b1e65 100755
--- a/impls/scala/run
+++ b/impls/scala/run
@@ -1,2 +1,3 @@
-#!/usr/bin/env bash
-exec java -classpath "$(dirname $0)/target/scala-2.11/mal.jar" ${STEP:-stepA_mal} "$@"
+#!/bin/sh
+set -Cefu
+exec java -classpath target/scala-2.11/mal.jar ${STEP:-stepA_mal} "$@"
diff --git a/impls/scheme/run b/impls/scheme/run
index 72fda6bcc8..ab089dc050 100755
--- a/impls/scheme/run
+++ b/impls/scheme/run
@@ -1,9 +1,9 @@
-#!/usr/bin/env bash
-basedir=$(dirname $0)
+#!/bin/sh
+set -Cefu
 step=${STEP:-stepA_mal}
 
 case ${scheme_MODE:-chibi} in
-    chibi)       exec chibi-scheme -I$basedir $basedir/$step.scm      "$@" ;;
+    chibi)       exec chibi-scheme $step.scm                         "$@" ;;
     kawa)        if [ -e /usr/share/kawa/lib/kawa.jar ]; then
                      kawa=/usr/share/kawa/lib/kawa.jar
                   elif [ -e /usr/local/share/kawa/lib/kawa.jar ]; then
@@ -12,9 +12,9 @@ case ${scheme_MODE:-chibi} in
                      echo >&2 'Failed to find kawa.jar.'
                      exit 1
                  fi
-                 exec java -cp $kawa:$basedir/out $step               "$@" ;;
-    gauche)      exec gosh -I$basedir $basedir/$step.scm              "$@" ;;
-    chicken)     CHICKEN_REPOSITORY=$basedir/eggs exec $basedir/$step "$@" ;;
+                 exec java -cp $kawa:out $step                       "$@" ;;
+    gauche)      exec gosh -I. $step.scm                             "$@" ;;
+    chicken)     CHICKEN_REPOSITORY=eggs exec ./$step                "$@" ;;
     sagittarius) if command -v sash >/dev/null 2>&1; then
                      sagittarius=sash
                  elif command -v sagittarius >/dev/null 2>&1; then
@@ -23,8 +23,8 @@ case ${scheme_MODE:-chibi} in
                      echo >&2 'Failed to find sash or sagittarius.'
                      exit 1
                  fi
-                 exec $sagittarius -n -L$basedir $basedir/$step.scm   "$@" ;;
-    cyclone)     exec $basedir/$step                                  "$@" ;;
-    foment)      exec foment $basedir/$step.scm                       "$@" ;;
+                 exec $sagittarius -n -L. $step.scm                  "$@" ;;
+    cyclone)     exec ./$step                                        "$@" ;;
+    foment)      exec foment $step.scm                               "$@" ;;
     *) echo "Invalid scheme_MODE: $scheme_MODE"; exit 2 ;;
 esac
diff --git a/impls/skew/run b/impls/skew/run
index 893cbb59c7..d1135e76d4 100755
--- a/impls/skew/run
+++ b/impls/skew/run
@@ -1,2 +1,3 @@
-#!/usr/bin/env bash
-exec node $(dirname $0)/${STEP:-stepA_mal}.js "$@"
+#!/bin/sh
+set -Cefu
+exec node ${STEP:-stepA_mal}.js "$@"
diff --git a/impls/sml/run b/impls/sml/run
index 6e11defbfb..5ffd062744 100755
--- a/impls/sml/run
+++ b/impls/sml/run
@@ -1,2 +1,3 @@
-#!/usr/bin/env bash
-exec $(dirname $0)/${STEP:-stepA_mal} "$@"
+#!/bin/sh
+set -Cefu
+exec ./${STEP:-stepA_mal} "$@"
diff --git a/impls/swift3/run b/impls/swift3/run
index 6e11defbfb..5ffd062744 100755
--- a/impls/swift3/run
+++ b/impls/swift3/run
@@ -1,2 +1,3 @@
-#!/usr/bin/env bash
-exec $(dirname $0)/${STEP:-stepA_mal} "$@"
+#!/bin/sh
+set -Cefu
+exec ./${STEP:-stepA_mal} "$@"
diff --git a/impls/swift4/run b/impls/swift4/run
index 6e11defbfb..5ffd062744 100755
--- a/impls/swift4/run
+++ b/impls/swift4/run
@@ -1,2 +1,3 @@
-#!/usr/bin/env bash
-exec $(dirname $0)/${STEP:-stepA_mal} "$@"
+#!/bin/sh
+set -Cefu
+exec ./${STEP:-stepA_mal} "$@"
diff --git a/impls/swift6/run b/impls/swift6/run
index 8a2cee3d04..5163410dfe 100755
--- a/impls/swift6/run
+++ b/impls/swift6/run
@@ -1,2 +1,3 @@
 #!/bin/sh
-exec $(dirname $0)/.build/${STEP:-stepA_mal} "$@"
+set -Cefu
+exec .build/${STEP:-stepA_mal} "$@"
diff --git a/impls/tcl/run b/impls/tcl/run
index 443068da76..be3858ef90 100755
--- a/impls/tcl/run
+++ b/impls/tcl/run
@@ -1,2 +1,3 @@
-#!/usr/bin/env bash
-exec tclsh $(dirname $0)/${STEP:-stepA_mal}.tcl ${RAW:+--raw} "$@"
+#!/bin/sh
+set -Cefu
+exec tclsh ${STEP:-stepA_mal}.tcl ${RAW:+--raw} "$@"
diff --git a/impls/tests/run_argv_test.sh b/impls/tests/run_argv_test.sh
index e3682e4f9f..25859019ef 100755
--- a/impls/tests/run_argv_test.sh
+++ b/impls/tests/run_argv_test.sh
@@ -1,4 +1,5 @@
-#!/usr/bin/env bash
+#!/bin/sh
+set -Cefu
 
 #
 # Usage: run_argv_test.sh <command line arguments to run mal>
@@ -21,7 +22,7 @@ if [ -z "$1" ] ; then
   exit 1
 fi
 
-root="$(dirname $0)"
+root=../tests
 
 out="$( $@ $root/print_argv.mal aaa bbb ccc | tr -d '\r' )"
 assert_equal '("aaa" "bbb" "ccc")' "$out"
diff --git a/impls/ts/run b/impls/ts/run
index 893cbb59c7..d1135e76d4 100755
--- a/impls/ts/run
+++ b/impls/ts/run
@@ -1,2 +1,3 @@
-#!/usr/bin/env bash
-exec node $(dirname $0)/${STEP:-stepA_mal}.js "$@"
+#!/bin/sh
+set -Cefu
+exec node ${STEP:-stepA_mal}.js "$@"
diff --git a/impls/vala/run b/impls/vala/run
index 6e11defbfb..5ffd062744 100755
--- a/impls/vala/run
+++ b/impls/vala/run
@@ -1,2 +1,3 @@
-#!/usr/bin/env bash
-exec $(dirname $0)/${STEP:-stepA_mal} "$@"
+#!/bin/sh
+set -Cefu
+exec ./${STEP:-stepA_mal} "$@"
diff --git a/impls/vb/run b/impls/vb/run
index 91beef2d69..8ea6fdbea1 100755
--- a/impls/vb/run
+++ b/impls/vb/run
@@ -1,2 +1,3 @@
-#!/usr/bin/env bash
-exec mono $(dirname $0)/${STEP:-stepA_mal}.exe ${RAW:+--raw} "$@"
+#!/bin/sh
+set -Cefu
+exec mono ${STEP:-stepA_mal}.exe ${RAW:+--raw} "$@"
diff --git a/impls/vbs/run b/impls/vbs/run
old mode 100644
new mode 100755
index ec0a7aba16..d225cb3a44
--- a/impls/vbs/run
+++ b/impls/vbs/run
@@ -1,4 +1,5 @@
-#!/usr/bin/env bash
+#!/bin/sh
+set -Cefu
 MAL_VBS_IMPL_NO_STDERR=1 MAL_VBS_IMPL_ECHO_STDIN=1 \
 WSLENV=MAL_VBS_IMPL_NO_STDERR/w:MAL_VBS_IMPL_ECHO_STDIN/w \
-exec cscript.exe -nologo "`wslpath -w "$(dirname $0)/${STEP:-stepA_mal}.vbs"`" "$@"
+exec cscript.exe -nologo ${STEP:-stepA_mal}.vbs "$@"
diff --git a/impls/vhdl/run b/impls/vhdl/run
index 2e60d28742..5201cee735 100755
--- a/impls/vhdl/run
+++ b/impls/vhdl/run
@@ -1,14 +1,13 @@
-#!/usr/bin/env bash
+#!/bin/sh
+set -efu
 
 # ghdl doesn't allow passing command-line arguments to the VHDL program.  To
 # circumvent that, we write the command-line arguments as lines in
 # vhdl_argv.tmp, and read the content of that file at the beginning of the VHDL
 # program.
 
-bin="$(dirname $0)/${STEP:-stepA_mal}"
-
 for arg; do
     echo "$arg"
 done > vhdl_argv.tmp
 
-exec $bin
+exec ./${STEP:-stepA_mal}
diff --git a/impls/vimscript/run b/impls/vimscript/run
index 6a98e91302..2cb7a320b4 100755
--- a/impls/vimscript/run
+++ b/impls/vimscript/run
@@ -1,4 +1,5 @@
 #!/bin/sh
+set -Cefu
 
 # Run Vim in ex mode (-e) and run the given script ($1) on startup. Our scripts
 # end with 'qall!' which causes actual Vim UI to never start up.
@@ -7,10 +8,9 @@
 #
 # See: http://vim.wikia.com/wiki/Vim_as_a_system_interpreter_for_vimscript
 
-rundir=`dirname $0`
-export LD_LIBRARY_PATH=`readlink -f $rundir`
-vimscriptfile="$(dirname $0)/${STEP:-stepA_mal}.vim"
-if [ x$DEBUG = x ] ; then
+export LD_LIBRARY_PATH=.
+vimscriptfile=${STEP:-stepA_mal}.vim
+if [ -n "${DEBUG:-}" ] ; then
   exec 2> /dev/null
 fi
 exec vim -i NONE -V1 -nNesS $vimscriptfile -- "$@" | cat
diff --git a/impls/wasm/run b/impls/wasm/run
index 764b5d920f..5958c5be40 100755
--- a/impls/wasm/run
+++ b/impls/wasm/run
@@ -1,17 +1,18 @@
-#!/usr/bin/env bash
+#!/bin/sh
+set -Cefu
 case ${wasm_MODE:-js} in
 wasmtime)
-    exec wasmtime --dir=./ --dir=../ --dir=/ $(dirname $0)/${STEP:-stepA_mal}.wasm "$@" ;;
+    exec wasmtime --dir=./ --dir=../ --dir=/ ${STEP:-stepA_mal}.wasm "$@" ;;
 wasmer)
-    exec wasmer run --dir=./ --dir=../ --dir=/ $(dirname $0)/${STEP:-stepA_mal}.wasm -- "$@" ;;
+    exec wasmer run --dir=./ --dir=../ --dir=/ ${STEP:-stepA_mal}.wasm -- "$@" ;;
 warpy)
-    exec warpy --argv --memory-pages 256 $(dirname $0)/${STEP:-stepA_mal}.wasm "$@" ;;
+    exec warpy --argv --memory-pages 256 ${STEP:-stepA_mal}.wasm "$@" ;;
 wax)
-    exec wax $(dirname $0)/${STEP:-stepA_mal}.wasm "$@" ;;
+    exec wax ${STEP:-stepA_mal}.wasm "$@" ;;
 wace_libc)
-    exec wace $(dirname $0)/${STEP:-stepA_mal}.wasm "$@" ;;
+    exec wace ${STEP:-stepA_mal}.wasm "$@" ;;
 wace_fooboot)
     echo >&2 "wace_fooboot mode not yet supported" ;;
 node|js|*)
-    exec node run.js $(dirname $0)/${STEP:-stepA_mal}.wasm "$@" ;;
+    exec node run.js ${STEP:-stepA_mal}.wasm "$@" ;;
 esac
diff --git a/impls/wren/run b/impls/wren/run
index f8cfe496d9..5709bd1b38 100755
--- a/impls/wren/run
+++ b/impls/wren/run
@@ -1,2 +1,3 @@
-#!/usr/bin/env bash
-exec wren $(dirname $0)/${STEP:-stepA_mal}.wren "$@"
+#!/bin/sh
+set -Cefu
+exec wren ${STEP:-stepA_mal}.wren "$@"
diff --git a/impls/yorick/run b/impls/yorick/run
index 4f35ebe814..4431fca9b8 100755
--- a/impls/yorick/run
+++ b/impls/yorick/run
@@ -1,3 +1,3 @@
-#!/usr/bin/env bash
-export YORICK_MAL_PATH="$(dirname $0)"
-exec yorick -batch "$YORICK_MAL_PATH/${STEP:-stepA_mal}.i" "$@"
+#!/bin/sh
+set -Cefu
+exec yorick -batch ${STEP:-stepA_mal}.i "$@"
diff --git a/impls/yorick/step1_read_print.i b/impls/yorick/step1_read_print.i
index 8a97cb8cf1..8d4bde5320 100644
--- a/impls/yorick/step1_read_print.i
+++ b/impls/yorick/step1_read_print.i
@@ -1,4 +1,3 @@
-set_path, get_env("YORICK_MAL_PATH") + ":" + get_path()
 require, "reader.i"
 require, "printer.i"
 
diff --git a/impls/yorick/step2_eval.i b/impls/yorick/step2_eval.i
index 40730a4967..984679c68b 100644
--- a/impls/yorick/step2_eval.i
+++ b/impls/yorick/step2_eval.i
@@ -1,4 +1,3 @@
-set_path, get_env("YORICK_MAL_PATH") + ":" + get_path()
 require, "reader.i"
 require, "printer.i"
 require, "core.i"
diff --git a/impls/yorick/step3_env.i b/impls/yorick/step3_env.i
index 604fb35a20..845ce2572d 100644
--- a/impls/yorick/step3_env.i
+++ b/impls/yorick/step3_env.i
@@ -1,4 +1,3 @@
-set_path, get_env("YORICK_MAL_PATH") + ":" + get_path()
 require, "reader.i"
 require, "printer.i"
 require, "core.i"
diff --git a/impls/yorick/step4_if_fn_do.i b/impls/yorick/step4_if_fn_do.i
index 6dac870716..a1bd63e183 100644
--- a/impls/yorick/step4_if_fn_do.i
+++ b/impls/yorick/step4_if_fn_do.i
@@ -1,4 +1,3 @@
-set_path, get_env("YORICK_MAL_PATH") + ":" + get_path()
 require, "reader.i"
 require, "printer.i"
 require, "core.i"
diff --git a/impls/yorick/step5_tco.i b/impls/yorick/step5_tco.i
index a9c8ffd96b..4f2011e7f7 100644
--- a/impls/yorick/step5_tco.i
+++ b/impls/yorick/step5_tco.i
@@ -1,4 +1,3 @@
-set_path, get_env("YORICK_MAL_PATH") + ":" + get_path()
 require, "reader.i"
 require, "printer.i"
 require, "core.i"
diff --git a/impls/yorick/step6_file.i b/impls/yorick/step6_file.i
index 9780f11926..843c08f024 100644
--- a/impls/yorick/step6_file.i
+++ b/impls/yorick/step6_file.i
@@ -1,4 +1,3 @@
-set_path, get_env("YORICK_MAL_PATH") + ":" + get_path()
 require, "reader.i"
 require, "printer.i"
 require, "core.i"
diff --git a/impls/yorick/step7_quote.i b/impls/yorick/step7_quote.i
index 4cd664ac38..c8eb843655 100644
--- a/impls/yorick/step7_quote.i
+++ b/impls/yorick/step7_quote.i
@@ -1,4 +1,3 @@
-set_path, get_env("YORICK_MAL_PATH") + ":" + get_path()
 require, "reader.i"
 require, "printer.i"
 require, "core.i"
diff --git a/impls/yorick/step8_macros.i b/impls/yorick/step8_macros.i
index 0060ecec7e..1ffcf9fe18 100644
--- a/impls/yorick/step8_macros.i
+++ b/impls/yorick/step8_macros.i
@@ -1,4 +1,3 @@
-set_path, get_env("YORICK_MAL_PATH") + ":" + get_path()
 require, "reader.i"
 require, "printer.i"
 require, "core.i"
diff --git a/impls/yorick/step9_try.i b/impls/yorick/step9_try.i
index 73df6647b9..f3e2308c9a 100644
--- a/impls/yorick/step9_try.i
+++ b/impls/yorick/step9_try.i
@@ -1,4 +1,3 @@
-set_path, get_env("YORICK_MAL_PATH") + ":" + get_path()
 require, "reader.i"
 require, "printer.i"
 require, "core.i"
diff --git a/impls/yorick/stepA_mal.i b/impls/yorick/stepA_mal.i
index 5251fafe8c..3205838d51 100644
--- a/impls/yorick/stepA_mal.i
+++ b/impls/yorick/stepA_mal.i
@@ -1,4 +1,3 @@
-set_path, get_env("YORICK_MAL_PATH") + ":" + get_path()
 require, "reader.i"
 require, "printer.i"
 require, "core.i"
diff --git a/impls/zig/run b/impls/zig/run
index 9b1b3df961..048ef39072 100755
--- a/impls/zig/run
+++ b/impls/zig/run
@@ -1,2 +1,3 @@
 #!/bin/sh
-exec $(dirname $0)/zig-out/bin/${STEP:-stepA_mal} "$@"
+set -Cefu
+exec zig-out/bin/${STEP:-stepA_mal} "$@"
diff --git a/process/guide.md b/process/guide.md
index bda640206d..f8ec3f1c59 100644
--- a/process/guide.md
+++ b/process/guide.md
@@ -113,18 +113,31 @@ quux_STEP_TO_PROG = impls/quux/$($(1)).qx
   the "STEP" environment variable for the implementation step to run
   and defaults to "stepA_mal". Make sure the run script has the
   executable file permission set (or else the test runner might fail with a
-  permission denied error message). The following are examples of "run"
+  permission denied error message).
+
+  In order to disambiguate relative paths in command line arguments,
+  library search paths and so on, "run" will by convention always
+  executed in the implementation directory.
+
+```
+cd impls/quux
+./run ../tests/step0_repl.mal
+```
+
+  The following are examples of "run"
   scripts for a compiled language and an interpreted language (where
   the interpreter is named "quux"):
 
 ```
-#!/usr/bin/env bash
-exec $(dirname $0)/${STEP:-stepA_mal} "${@}"
+#!/bin/sh
+set -Cefu
+exec ./${STEP:-stepA_mal} "$@"
 ```
 
 ```
-#!/usr/bin/env bash
-exec quux $(dirname $0)/${STEP:-stepA_mal}.qx "${@}"
+#!/bin/sh
+set -Cefu
+exec quux ${STEP:-stepA_mal}.qx "$@"
 ```
 
 This allows you to run tests against your implementation like this: