From 11228033119df6a25da0602de996bb0426966f78 Mon Sep 17 00:00:00 2001
From: Noah Pederson <noah@packetlost.dev>
Date: Mon, 22 Jun 2026 10:23:18 -0500
Subject: [PATCH] Avoid shell wrapper for signal forwarding

---
 diag => disag | 94 +++++++++++++++++++++++++++++----------------------
 1 file changed, 53 insertions(+), 41 deletions(-)
 rename diag => disag (77%)

diff --git a/diag b/disag
similarity index 77%
rename from diag
rename to disag
index c574579..072b752 100755
--- a/diag
+++ b/disag
@@ -33,7 +33,7 @@ Notes:
   Display prefixes and ANSI colors are never written to log files.
   Colors are used only when stdout is a terminal.
   diag uses anonymous rc pipes internally and only writes paths named with -f.
-  Signal forwarding uses sh and setsid so child command groups receive signals.
+  Signals are forwarded to child processes with kill.
 
 Examples:
   diag 'echo hello'
@@ -64,9 +64,51 @@ fn runone {
 	if(! ~ $file '')
 		> $file
 
+	fn stoprunone {
+		sig=$1
+		for(pid in $runpids)
+			kill -^$sig -^$pid >[2]/dev/null
+		for(pid in $runpids)
+			kill -^$sig $pid >[2]/dev/null
+		wait
+		exit sig^$sig
+	}
+
+	fn sigint {
+		stoprunone INT
+	}
+
+	fn sigterm {
+		stoprunone TERM
+	}
+
+	fn sigquit {
+		stoprunone QUIT
+	}
+
+	fn sighup {
+		stoprunone HUP
+	}
+
 	{
-		rc -c $cmd >[2=3] |
-		awk -v logfile=$file -v name=$name -v color=$color '
+		{
+			rc -c $cmd >[2=3] |
+			awk -v logfile=$file -v name=$name -v color=$color '
+				{
+					if(logfile != "") {
+						print $0 >> logfile
+						fflush(logfile)
+					}
+					line = $0
+					if(name != "")
+						line = "[" name "] " line
+					if(color != "")
+						line = sprintf("%c[%sm%s%c[0m", 27, color, line, 27)
+					print line
+					fflush()
+				}
+			'
+		} |[3] awk -v logfile=$file -v name=$name -v color=$color '
 			{
 				if(logfile != "") {
 					print $0 >> logfile
@@ -77,25 +119,13 @@ fn runone {
 					line = "[" name "] " line
 				if(color != "")
 					line = sprintf("%c[%sm%s%c[0m", 27, color, line, 27)
-				print line
-				fflush()
+				print line > "/dev/stderr"
+				fflush("/dev/stderr")
 			}
 		'
-	} |[3] awk -v logfile=$file -v name=$name -v color=$color '
-		{
-			if(logfile != "") {
-				print $0 >> logfile
-				fflush(logfile)
-			}
-			line = $0
-			if(name != "")
-				line = "[" name "] " line
-			if(color != "")
-				line = sprintf("%c[%sm%s%c[0m", 27, color, line, 27)
-			print line > "/dev/stderr"
-			fflush("/dev/stderr")
-		}
-	'
+	} &
+	runpids=$apid
+	wait $runpids
 }
 
 if(! ~ $#* 0 && ~ $1 --diag-run-one) {
@@ -106,6 +136,8 @@ if(! ~ $#* 0 && ~ $1 --diag-run-one) {
 
 fn stopall {
 	sig=$1
+	for(pid in $apids)
+		kill -^$sig -^$pid >[2]/dev/null
 	for(pid in $apids)
 		kill -^$sig $pid >[2]/dev/null
 	wait
@@ -156,27 +188,7 @@ fn launch {
 		color=$colors($color_index)
 	}
 
-	sh -c '
-		child=
-		forward() {
-			sig=$1
-			code=$2
-			if test -n "$child"
-			then
-				kill -$sig -$child 2>/dev/null
-				wait "$child"
-			fi
-			exit "$code"
-		}
-		trap "forward INT 130" INT
-		trap "forward TERM 143" TERM
-		trap "forward QUIT 131" QUIT
-		trap "forward HUP 129" HUP
-		setsid -w "$@" &
-		child=$!
-		wait "$child"
-		exit $?
-	' sh $prog --diag-run-one $cmd $file $name $color &
+	$prog --diag-run-one $cmd $file $name $color &
 	writers=($writers $apid)
 }
 
-- 
2.51.2