beep

#!/bin/sh
summary="Alert by beeping or flashing the console"
website="Part of misc-scripts: https://github.com/adamhotep/misc-scripts"
version="beep 0.3.20240519.0 Copyright 2000+ by Adam Katz, GPL v2+"
# Run --help to learn more

# sameas(): True when this program ($0) is the same as the argument ($1) {{{
sameas() {
  local a="$(readlink -f "$0" 2>/dev/null || echo "$0")"
  local b="$(readlink -f "$1" 2>/dev/null || echo "$1")"
  [ "$0" = "$1" ] || [ "$a" = "$1" ] || [ "$0" = "$b" ] || [ "$a" = "$b" ] \
    || diff -q "$0" "$1" >/dev/null 2>&1
}
# }}} end of sameas()

# Set secondary `beep` program for audible bells (if any) to $app {{{
app=
# if not remote and we have a console beep app save that as $app
if [ -z "$SSH_TTY" ]; then
  # allow name collisions: we want the first `beep` that isn't THIS.
  app="$(
    IFS=:
    for path in $PATH; do
      b="$path/beep"
      if [ -x "$b" ] && [ "$b" != "$0" ] && ! sameas "$b"; then
        echo "$path/beep"
        break
      fi
    done
  )"
  if [ -n "$app" ]; then
    app_options=" [BEEP_OPTIONS]"
  fi
fi
# }}} end of audible bell program detection

help() {
  echo "$summary"
  iam="${0##*/}"
  u="Usage:"
  usage="[--visual|-v]$app_options"
  vusage="[--audible|-a]$app_options"

  linkme() { printf '\nSymlink this to `%s` for flagless support\n' "$1"; }
  case "$iam" in
    ( vb* )
      beep="${0%/*}/${iam#v}"
      if sameas "$beep"; then
        echo "$u ${iam#v} $usage"
        u="      "
      else linkme "$beep"
      fi
      echo "$u $iam $vusage"
      ;;
    ( * )
      vbeep="${0%/*}/v$iam"
      echo "$u $iam $usage"
      if sameas "$vbeep"; then
        echo "       v$iam $vusage"
      else linkme "$vbeep"
      fi
      ;;
  esac
  echo ""
  echo "  --visual, -v    Silently flash the console"
  echo "  --audible, -a   Sound a bell"
  if [ -n "$app_options" ]; then
    echo ""
    echo "  BEEP_OPTIONS are observed unless we're in visual bell mode."
    echo "  More detail at \`$iam -a --help\`"
  fi
  echo ""
  version
}
version() {
  if [ -x "$app" ]; then
    "$app" --version 2>&1 |awk 'NR == 1 { print "Using " $0; exit }'
  fi
  printf "%s\n%s\n" "$website" "$version"
  exit
}

if [ "${1#--help}" != "${1#-h}" ]; then
  help
elif [ "${1#--ver}" != "${1#-V}" ]; then
  version
fi

visual=
audible=
if   [ "${1#--vis}" != "${1#-v}" ]; then visual=1; shift
elif [ "${1#--aud}" != "${1#-a}" ]; then audible=1; shift; fi

# visual bell if (named (vbeep or vbell) and not --audible/-a) or if --visual/-v
if [ "$0" != "${0%vbe*}" -a -z "$audible" ] || [ -n "$visual" ]; then
  tput flash 2>/dev/null || {
    # fallback method
    printf "\e[?5h"	# un-reverse video
    # GNU, BSD/Mac, & Busybox support decimals. Perl fallback loads in ~0.01s
    sleep 0.1 2>/dev/null || perl -e 'select(undef, undef, undef, 0.09)'
    printf "\e[?5l"	# reverse video
  } 2>/dev/null
  exit $?
fi

if [ -x "$app" ]; then	# if we have a console beep app, use it now
  exec "$app" "$@"
else			# otherwise, print the alert sequence
  printf "\a"
fi