UNTESTED IF BROKEN ROLL BACK TO LAST COMMIT TESTING THIS IS BORING offload work to awk

com/com

@@ -5,7 +5,7 @@ set -e
 # http://www.iq0.com/duffgram/com.html implementation
 # (consulted source to see what -n did)
 
-arv0="$0"; shell=sh
+arv0="$0"; shell='sh -c'
 
 usage(){
 	printf 'Usage: %s (-n) (file...)\n' "$argv0" >&2
@@ -20,7 +20,7 @@ do
 	shift
 	printf '%s\n' "$arg" \
 		| grep 'n' >/dev/null 2>&1 \
-			&& shell=cat \
+			&& shell=echo \
 			|| true
 	printf '%s\n' "$arg" \
 		| grep '[^-n]' >/dev/null 2>&1 \
@@ -41,31 +41,36 @@ test -n "$1" \
 
 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' "$1" | sed 's,\.[^.]*$,,')" '
-{
+	cmd="$(<"$1" awk '
+processed == 0 && /\/\*%/ {
+	sub(/.*\/\*%[space]*/, "");
 	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) == "#")
+		else if(substr($0, i, 1) == "#"){
+			if(stem == 0){
+				stem = ARGV[1];
+				sub(/\.[^.]*$/, "", stem)
+			}
 			printf("%s", stem)
-		else if(substr($0, i, 1) == "%")
-			printf("%s", name)
+		}else if(substr($0, i, 1) == "%")
+			printf("%s", ARGV[1])
 		else
 			printf("%s", substr($0, i, 1))
 	}
 	printf("%s\n", substr($0, i, 2))
+	processed = 1
 }
-	'	| $shell
+END {
+	if(processed == 0){
+		# https://www.gnu.org/software/gawk/manual/html_node/
+		#	Special-FD.html
+		printf("%s: no command\n", ARGV[2]) > "/dev/stderr"
+		exit 65 # sysexits(3) EX_DATAERR
+	}
+}
+	' "$1" "$argv0")" && exit 65 # sysexits(3) DATA_ERR
+	$shell "$cmd"
 	printf '%s\n' "$1" >>.comfile
 	shift
 done