#!/bin/sh
#
# speakd
#
# (C) 2003 Malte J. Wetz <mail@malte-wetz.de>
#
# A simple shell script that starts speak in a loop reading
# from a named pipe.
#

# Don't touch these two!
BASENAME=`basename $0`
VERSION="0.0.2"

##############################################################################
# SETTINGS: Change the following parameters to meet your requirements.
# If you don't know what you're doing, just don't do anything or at 
# least keep a backup!
##############################################################################


# What is the name of the named pipe from which speak should get its
# input data?
DEVICE="/dev/speech"

# Where is the speak script located?
SPEAK="/usr/local/bin/speak"

# With what parameters should speak be started?
SPEAK_PARAMS="-a -n -p"

# Set to 'yes', if you want speakd to die if speak produces an error
# while synthesizing. Set to 'no', if speak should ignore such
# situations.
DIE_ON_ERROR="yes"

# What action should be made upon usage of the named pipe?
ACTION=""
#ACTION="logger -t $BASENAME successfully synthesized text from $DEVICE"
#ACTION="echo -n ."

# Create a pid file for this process at the specified location
PIDFILE="/var/run/$BASENAME.pid"

##############################################################################
# END OF SETTINGS: There should be nothing to change below this point!
##############################################################################


# sanity check: is there another speakd running?
test -e "$PIDFILE" && {
  PID=`cat "$PIDFILE"`
  result=`ps -p "$PID" --no-headers`
  
  if [ -z "$result" ]; then
    echo "warning: pid file ($PID) found, appears to be stale, removing..."
    rm -f "$PIDFILE"
  else
    echo "error: another $BASENAME seems to be running with pid $PID, exit."
    exit 1
  fi
}

# sanity check: does the device exist and is it readable?
test -r "$DEVICE" || {
  echo "error: $DEVICE does not exists or is not readable. exit."
  exit 1
}

# This function is called upon exit. It will remove the pid file.
function finalize {
  test -e "$PIDFILE" && rm -f "$PIDFILE"
}

# Evaluate command line options
while getopts hnep: switch; do
  case "$switch" in
    n) LINE_READ_MODE=yes		;;
    e) DIE_ON_ERROR=yes			;;
    p) PIDFILE=$OPTARG			;;
    h) cat<<EOF
$BASENAME $VERSION  (C) Malte J. Wetz <mail@malte-wetz.de>

DESCRIPTION
  Shell-script daemon that listens on $DEVICE and uses the script 'speak'
  to synthesize any text written to it. $DEVICE must be a named-pipe.

USAGE
  $BASENAME [-n] [-e] [-p <file>]

OPTIONS
  -n
    Reads single lines from $DEVICE and synthesize them. Otherwise,
    $BASENAME will wait until the named pipe is closed on the remote end and 
    then speak the complete text. Note: in line-reading mode, some
    speak-filters will not work (i.e. the filter that removes linefeeds from
    the pipe).
  -e
    Exit on error. If an error occurs during synthesis, $BASENAME will
    terminate until the issue is resolved. If not specified, $BASENAME
    will continue waiting for data and try again.
  -p <file>
    Use the specified file as pid file. Default is $PIDFILE.
EOF
    exit
    ;;
  esac
done


# Create the pid file
test -z "$PIDFILE" || echo $$ > "$PIDFILE"

# Set exit trap
trap finalize 0 


if [ "$LINE_READ_MODE" = "yes" ]; then
  while true; do
    while read line; do
      [ -z "$line" ] || {
        echo "$line" | $SPEAK $SPEAK_PARAMS || {
          [ "$DIE_ON_ERROR" = yes ] && exit 1
        }
        [ -z "$ACTION" ] || $ACTION
      }
    done < $DEVICE
  done
else
  while true; do
    $SPEAK $SPEAK_PARAMS < $DEVICE || {
      [ "$DIE_ON_ERROR" = yes ] && exit 1
    }
    [ -z "$ACTION" ] || $ACTION
  done
fi


# We're done here
exit 0