Zsh: Make functions also usable as shell scripts

.config/zsh/functions/cat-highlight

@@ -1,9 +1,7 @@
-# -*- mode: shell-script; -*-
-
+#!/usr/bin/env zsh
 # Highlight cat output with whatever less is using for highlighting. The command
 # in $LESSOPEN needs to be able to work with multiple files.
-function cat-highlight()
-{
+
 # Check if we are in a terminal and $LESSOPEN is not empty
 if [[ -t 1 && -n "${LESSOPEN}" ]]; then
     local -a args
@@ -22,4 +20,3 @@ function cat-highlight()
 else
     \cat "${@}"
 fi
-}

.config/zsh/functions/export-emacs

@@ -1,8 +1,6 @@
-# -*- mode: shell-script; -*-
-
+#!/usr/bin/env zsh
 # Export variable to Emacs.
-function export-emacs
-{
+
 if [[ ARGC -eq 0 ]]; then
     print -u 2 "Usage: ${0} <variable> …"
     return 1
@@ -15,4 +13,3 @@ function export-emacs
     value=$(eval print \"\$${name}\")
     emacsclient -e "(setenv \"${name}\" \"${value}\")" >/dev/null
 done
-}

.config/zsh/functions/gdb_get_backtrace

@@ -1,8 +1,6 @@
-# -*- mode: shell-script; -*-
-
+#!/usr/bin/env zsh
 # Get backtrace from gdb
-function gdb_get_backtrace()
-{
+
 if [[ ${ARGC} -ne 2 ]]; then
     print -u 2 "Usage: ${0} <executable> <core dump>"
     return 1
@@ -16,4 +14,3 @@ function gdb_get_backtrace()
     --quiet \
     -ex "thread apply all bt full" \
     -ex "quit"
-}

.config/zsh/functions/mksmol

@@ -1,9 +1,7 @@
-# -*- mode: shell-script; -*-
-
+#!/usr/bin/env zsh
 # Makes all files in <directory> lower case. Works with Non-ASCII characters.
 # Equivalent to `zmv "${dir}/(*)" '${dir}/${1:l}'`
-function mksmol()
-{
+
 if [[ ${ARGC} -ne 1 ]]; then
     print -u 2 "Usage: ${0} <directory>" >&2
     return 1
@@ -15,4 +13,3 @@ function mksmol()
     newfile="${dir}/${basename:l}"
     [[ "${file}" != "${newfile}" ]] && mv "${file}" "${newfile}" || :
 done
-}