Added: Possibilty to run date through background fifo for bash <5

bashtop

@@ -200,16 +200,36 @@ if [[ -n $EPOCHREALTIME ]]; then
 		ms_out=$((${EPOCHREALTIME/[.,]/}/1000))
 	}
 
-#* If not, use date command
+#* If not, use date command, through fifo if possible
 else
-	get_ms() { #? Set given variable to current epoch millisecond with date command
-		local count
-		local -n ms_out=$1
-		ms_out=""
-		while [[ -z $ms_out ]] && ((++count<=10)); do
+	tmpdir=""
+	if [[ -n $XDG_RUNTIME_DIR && -w "$XDG_RUNTIME_DIR" ]]; then 
+		tmpdir="$XDG_RUNTIME_DIR"
+	elif [[ -w /dev/shm ]]; then 
+		tmpdir="/dev/shm"
+	elif [[ -w /tmp ]]; then 
+		tmpdir="/tmp"
+	fi
+
+	if [[ -n $tmpdir ]] && command -v stdbuf >/dev/null 2>&1; then
+		mkfifo "${tmpdir}/bashtop_datefifo"
+		exec 5> >(exec stdbuf -o0 date -f - +%s%3N > "${tmpdir}/bashtop_datefifo" 2>&1)
+		exec 6< "${tmpdir}/bashtop_datefifo"
+		rm  "${tmpdir}/bashtop_datefifo"
+		
+		get_ms() { #? Set given variable to current epoch millisecond with date command through background fifo
+			local -n ms_out=$1
+     		echo now >&5 &&
+        	read -u 6 ms_out 
+		}
+
+	else
+		get_ms() { #? Set given variable to current epoch millisecond with forked date command
+			local -n ms_out=$1
+			ms_out=""
 			read ms_out < <(date +%s%3N)
-		done
-	}
+		}
+	fi
 fi
 
 init_() { #? Collect needed information and set options before startig main loop