Mini Shell

#!/usr/bin/sh
#
# Script to play audio tracks with different pitches 
# through a soundcard (cdda2wav must have soundcard
# support enabled).
#
# Pitches are specified in percentage with 100% being
# the original pitch, 50% being one octave lower, 200%
# one octave higher.
#
# based on a script from Raul Sobon, who created the pitch
# feature. Thanks Raul.
#
# usage: pitchplay <track a> <pitch a> <track b> <pitch b> ...
#
# example: pitchplay 1 90  3 140  5 50
# will play track 1 with a pitch of 90%,
#           track 3 with a pitch of 140%, and
#           track 5 with a pitch of 50%.
#
CDDA2WAV=icedax
#CDDA2WAVOPTS="-qeNP0 -n75"
CDDA2WAVOPTS="-qeNP0 -n40"

if [ $(( $# % 2 )) -eq 0 ]; then
  while [ $# -ge 2 ]; do
    echo playing track $1 with a pitch of $2%
    $CDDA2WAV $CDDA2WAVOPTS -t $1 -p $2
    RES=$?
    if [ $RES -ne 0 ]; then
      echo "$CDDA2WAV error, return value "$RES". Aborted." >&2
      break
    fi
    shift 2
  done
else
  echo "usage: $0 [<Tracknr> <Pitch>] ..." >&2
fi