From 3d5eddc0d9567e79087a429d81cc20c5b61ac2a6 Mon Sep 17 00:00:00 2001
From: dtb <git@trinity.moe>
Date: Sat, 22 Jul 2023 09:33:36 -0400
Subject: [PATCH] com(1)

---
 com/com | 71 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 71 insertions(+)
 create mode 100644 com/com

diff --git a/com/com b/com/com
new file mode 100644
index 0000000..3d7e328
--- /dev/null
+++ b/com/com
@@ -0,0 +1,71 @@
+#!/bin/sh
+
+set -e
+
+# http://www.iq0.com/duffgram/com.html implementation
+# (consulted source to see what -n did)
+
+arv0="$0"; shell=sh
+
+usage(){
+	printf 'Usage: %s (-n) (file...)\n' "$argv0" >&2
+	exit 64	# sysexits(3) EX_USAGE
+}
+
+for arg in "$@"
+do
+	printf '%s\n' "$arg" \
+		| grep '^-' >/dev/null 2>&1 \
+			|| break
+	shift
+	printf '%s\n' "$arg" \
+		| grep 'n' >/dev/null 2>&1 \
+			&& shell=cat \
+			|| true
+	printf '%s\n' "$arg" \
+		| grep '[^-n]' >/dev/null 2>&1 \
+			&& usage \
+			|| true
+	printf '%s\n' "$arg" \
+		| grep -- '-.*-' >/dev/null 2>&1 \
+			&& break \
+			|| true
+done
+
+test -n "$1" \
+	|| set -- "$(cat .comfile 2>/dev/null)" \
+	&& test -n "$1" \
+	|| usage
+
+>.comfile
+
+while	test -n "$1"
+do	
+	c="$(<"$1" grep '/\*%' 2>/dev/null | head -n 1)"
+	test -z "$c" \
+		&& printf '%s: no command\n' "$arv0" >&2 \
+		&& exit 65 \
+		|| true	#^- sysexits(3) EX_DATAERR
+
+	printf '%s\n' "$c" \
+		| sed	-e 's,.*/\*%[space]*,,' \
+		| awk \
+			-v name="$1" \
+			-v stem="$(printf '%s\n' "$1" | sed 's,\.[^.]*$,,')" '
+{
+	for(i = 0; i < length($0) - 1; ++i){
+		if(substr($0, i, 2) == "##" || substr($0, i, 2) == "%%")
+			printf("%s", substr($0, i++, 1))
+		else if(substr($0, i, 1) == "#")
+			printf("%s", stem)
+		else if(substr($0, i, 1) == "%")
+			printf("%s", name)
+		else
+			printf("%s", substr($0, i, 1))
+	}
+	printf("%s\n", substr($0, i, 2))
+}
+	'	| $shell
+	printf '%s\n' "$1" >>.comfile
+	shift
+done