sermon

#!/bin/sh
# sermon (part of ossobv/vcutil) // wdoekes/2023 // Public Domain
#
# sermon, the serial monitor, is more convenient for serial logs than
# screen(1).
#
# Usage:
#
#   sermon [-t] /dev/ttyUSB0 115200
#
# This sparks so much more joy than the Arduino 2.x IDE serial monitor.
# See: https://github.com/arduino/arduino-ide/issues/289
#
set -eu
test "${1:-}" = '-t' && { with_ts=true; shift; } || with_ts=false
dev=${1:-/dev/ttyACM0}
baud=${2:-115200}
stty -F "$dev" "$baud" raw -clocal -echo || {
    echo "Usage: ${0##*/} [-t] DEV BAUD" >&2; exit 1; }
echo "${0##*/} [-t] DEV BAUD; now listening on $dev with $baud baud" >&2
if $with_ts; then
    exec perl -e 'use strict;use warnings;
      use Time::HiRes qw(gettimeofday);use POSIX qw(strftime);
      my ($nl,$t,$ut)=1;while(sysread STDIN,$b,1){
      if($nl){($t,$ut)=gettimeofday;syswrite STDOUT,
      (strftime "%H:%M:%S",localtime $t).(sprintf ".%06d: ",$ut);$nl=0}
      $nl=1 if $b eq "\n";syswrite STDOUT,$b}' <"$dev"
else
    exec cat "$dev"
fi