set_asound_conf

#!/bin/bash

MM="/usr/local/MirrorCommand"
ASOUND_TMPL="${MM}/etc/asound.conf.tmpl"
ASOUND="/etc/asound.conf"
CARDS="/proc/asound/cards"
OUTSTR="__AUDIO_OUT__"
INPSTR="__AUDIO_IN__"
INPUT=
OUTPUT=

# Change these if you are not using a USB microphone or audio
#
# String to look for in /proc/asound/cards for audio output device
OUTGREP="USB-Audio"
# String to look for in /proc/asound/cards for audio input device
INGREP="USB-Audio"

usage() {
    printf "\nUsage: set_asound_conf [-c] [-e] [-l] [-n] [-o outfile] [-q] [-r] [-t template] [-u]" 
    printf "\nWhere:"
    printf "\n\t-c indicates perform a check and notify if update needed"
    printf "\n\t-e indicates perform an update of /etc/asound.conf"
    printf "\n\t-l indicates list audio input/output configured devices"
    printf "\n\t-n indicates non-interactive execution (guess at settings)"
    printf "\n\t-o 'outfile' specifies an alternate output file for generated asound.conf"
    printf "\n\t-q indicates quiet execution"
    printf "\n\t-r indicates restore original /etc/asound.conf"
    printf "\n\t-t 'template' specifies an alternate asound.conf template to use"
    printf "\n\t-u indicates display this usage message and exit"
    printf "\n\nDefault generated output is the file /etc/asound.conf"
    printf "\nDefault asound.conf template can be found in:"
    printf "\n\t/usr/local/MirrorCommand/etc/asound.conf.tmpl\n\n"
    exit 0
}

set_vol_card() {
  VOL="/usr/local/bin/vol"
  if [ "$1" ]
  then
    if [ -f ${VOL} ]
    then
      OUTCARD=$1
      ((OUTCARD--))
      VOLCARD=`grep ^CARD= ${VOL} | awk -F '=' ' { print $2 } '`
      [ ${VOLCARD} -eq ${OUTCARD} ] || {
        [ "${QUT}" ] || {
          echo "Updating ${VOL} with audio output card number"
        }
        cat ${VOL} | sed -e "s/CARD=${VOLCARD}/CARD=${OUTCARD}/" > /tmp/v$$
        sudo cp /tmp/v$$ ${VOL}
        rm -f /tmp/v$$
      }
    else
      [ "${QUT}" ] || {
        echo "/usr/local/bin/vol does not exist"
        echo "Skipping vol card default setting"
      }
    fi
  else
    [ "${QUT}" ] || {
      echo "No argument supplied to set_vol_card()"
      echo "Skipping vol card default setting"
    }
  fi
}

UPD=
CHK=
LST=
REV=
QUT=
SEL=1
while getopts celno:qrt:u flag; do
    case $flag in
        c)
            CHK=1
            ;;
        e)
            UPD=1
            ;;
        l)
            LST=1
            ;;
        n)
            SEL=
            ;;
        o)
            ASOUND="${OPTARG}"
            ;;
        q)
            QUT=1
            ;;
        r)
            REV=1
            ;;
        t)
            ASOUND_TMPL="${OPTARG}"
            ;;
        u)
            usage
            ;;
    esac
done
shift $(( OPTIND - 1 ))

[ "$LST" ] && {
  INP=
  OUT=
  grep card /etc/asound.conf | while read card
  do
    [ "$INP" ] || {
      echo "Audio Output:"
      aplay -l | grep "$card"
      INP=1
      echo ""
      continue
    }
    [ "$OUT" ] || {
      echo "Audio Input:"
      arecord -l | grep "$card"
      OUT=1
      echo ""
      continue
    }
  done
  exit 0
}

[ -f ${ASOUND_TMPL} ] || {
  [ "${QUT}" ] || {
    echo "Cannot locate ${ASOUND_TMPL}. Exiting."
  }
  exit 0
}

if [ "$REV" ]
then
  [ -f ${ASOUND}.orig ] && {
    sudo cp ${ASOUND}.orig ${ASOUND}
    sudo rm -f ${ASOUND}.orig
  }
else
  # Present a selection dialog to allow user to choose audio input and output
  echo ""
  device_options=()
  while read entry
  do
    devnum=`echo ${entry} | awk ' { print $1 } '`
    [ "${devnum}" -eq "${devnum}" ] 2> /dev/null || continue
    device=`echo ${entry} | awk -F ':' ' { print $2 } '`
    device=`echo ${device} | sed -e 's/^[[:space:]]*//' -e 's/[[:space:]]*$//'`
    device_options+=("${device}")
  done < <(cat ${CARDS})
  if [ "${SEL}" ]
  then
    device_options+=("Select For Me" "None" "Quit")
    PS3="${BOLD}Please enter the device you wish to use for AUDIO OUTPUT (numeric or text): ${NORMAL}"
    select opt in "${device_options[@]}"
    do
      case "$opt,$REPLY" in
        "Select For Me",*|*,"Select For Me"|"select for me",*|*,"select for me")
          OUTPUT=`grep ${OUTGREP} ${CARDS} | grep "DAC" | awk ' { print $1 } '`
          [ "${OUTPUT}" ] || {
            OUTPUT=`grep '\[Headphones' ${CARDS} | awk ' { print $1 } '`
          }
          [ "${OUTPUT}" ] || {
            OUTPUT=`grep ${OUTGREP} ${CARDS} | grep "Audio Device" | awk ' { print $1 } '`
          }
          [ "${OUTPUT}" ] && {
            OUTPUT=`echo ${OUTPUT} | sed -e 's/^[[:space:]]*//' -e 's/[[:space:]]*$//'`
          }
          [ "${OUTPUT}" ] || OUTPUT=1
          ;;
        "None",*|*,"None"|"none",*|*,"none")
          OUTPUT=1
          break
          ;;
        "Quit",*|*,"Quit"|"quit",*|*,"quit")
          exit 0
          ;;
        [0-9]*,*|*,[0-9]*)
          OUTPUT=${REPLY}
          ((OUTPUT--))
          break
          ;;
        *)
          printf "\nInvalid entry. Please try again"
          printf "\nEnter either a number or text of one of the menu entries\n"
          ;;
      esac
    done

    echo ""
    PS3="${BOLD}Please enter the device you wish to use for AUDIO INPUT (numeric or text): ${NORMAL}"
    select opt in "${device_options[@]}"
    do
      case "$opt,$REPLY" in
        "Select For Me",*|*,"Select For Me"|"select for me",*|*,"select for me")
          INPUT=`grep ${INGREP} ${CARDS} | grep "Webcam" | awk ' { print $1 } '`
          [ "${INPUT}" ] || {
            INPUT=`grep '\[Microphone' ${CARDS} | awk ' { print $1 } '`
          }
          [ "${INPUT}" ] || {
            INPUT=`grep ${INGREP} ${CARDS} | grep "Audio Device" | awk ' { print $1 } '`
          }
          [ "${INPUT}" ] && {
            INPUT=`echo ${INPUT} | sed -e 's/^[[:space:]]*//' -e 's/[[:space:]]*$//'`
          }
          [ "${INPUT}" ] || {
            if [ "${OUTPUT}" == "0" ]
            then
              INPUT=1
            else
              INPUT=0
            fi
          }
          ;;
        "None",*|*,"None"|"none",*|*,"none")
          if [ "${OUTPUT}" == "0" ]
          then
            INPUT=1
          else
            INPUT=0
          fi
          break
          ;;
        "Quit",*|*,"Quit"|"quit",*|*,"quit")
          exit 0
          ;;
        [0-9]*,*|*,[0-9]*)
          INPUT=${REPLY}
          ((INPUT--))
          break
          ;;
        *)
          printf "\nInvalid entry. Please try again"
          printf "\nEnter either a number or text of one of the menu entries\n"
          ;;
      esac
    done
  else
    OUTPUT=`grep ${OUTGREP} ${CARDS} | grep "DAC" | awk ' { print $1 } '`
    [ "${OUTPUT}" ] || {
      OUTPUT=`grep '\[Headphones' ${CARDS} | awk ' { print $1 } '`
    }
    [ "${OUTPUT}" ] || {
      OUTPUT=`grep ${OUTGREP} ${CARDS} | grep "Audio Device" | awk ' { print $1 } '`
    }
    [ "${OUTPUT}" ] && {
      OUTPUT=`echo ${OUTPUT} | sed -e 's/^[[:space:]]*//' -e 's/[[:space:]]*$//'`
    }
    [ "${OUTPUT}" ] || OUTPUT=1

    INPUT=`grep ${INGREP} ${CARDS} | grep "Webcam" | awk ' { print $1 } '`
    [ "${INPUT}" ] || {
      INPUT=`grep '\[Microphone' ${CARDS} | awk ' { print $1 } '`
    }
    [ "${INPUT}" ] || {
      INPUT=`grep ${INGREP} ${CARDS} | grep "Audio Device" | awk ' { print $1 } '`
    }
    [ "${INPUT}" ] && {
      INPUT=`echo ${INPUT} | sed -e 's/^[[:space:]]*//' -e 's/[[:space:]]*$//'`
    }
    [ "${INPUT}" ] || {
      if [ "${OUTPUT}" == "0" ]
      then
        INPUT=1
      else
        INPUT=0
      fi
    }
  fi

  # Generate a new asound.conf from the template
  cat ${ASOUND_TMPL} | \
    sed -e "s/${INPSTR}/${INPUT}/" -e "s/${OUTSTR}/${OUTPUT}/" > /tmp/asound$$

  SAME=
  [ -f ${ASOUND} ] && {
    diff /tmp/asound$$ ${ASOUND} > /dev/null
    [ $? -eq 0 ] && SAME=1
  }
  if [ "${CHK}" ]
  then
    if [ -f ${ASOUND} ]
    then
      if [ "${SAME}" ]
      then
        [ "${QUT}" ] || {
          echo "${ASOUND} is identical to a generated asound.conf. No need to update."
        }
        exit 0
      else
        [ "${QUT}" ] || {
          echo "${ASOUND} differs with generated asound.conf as follows:"
          diff /tmp/asound$$ ${ASOUND}
        }
        exit 1
      fi
    else
      [ "${QUT}" ] || {
        echo "No ${ASOUND} detected. Check not performed."
        echo "Use 'set_asound_conf -e' to generate and update ${ASOUND}"
      }
      exit 1
    fi
  else
    if [ "${UPD}" ]
    then
      if [ -f ${ASOUND} ]
      then
        if [ "${SAME}" ]
        then
          [ "${QUT}" ] || {
            echo "${ASOUND} is identical to a generated asound.conf. No need to update."
          }
          set_vol_card ${OUTPUT}
        else
          [ -f ${ASOUND}.orig ] || {
            [ "${QUT}" ] || {
              echo "Copying original ${ASOUND} to ${ASOUND}.orig"
            }
            sudo cp ${ASOUND} ${ASOUND}.orig
          }
          [ "${QUT}" ] || {
            echo "Installing generated asound.conf as ${ASOUND}"
          }
          sudo cp /tmp/asound$$ ${ASOUND}
          set_vol_card ${OUTPUT}
        fi
      else
        sudo cp /tmp/asound$$ ${ASOUND}
        set_vol_card ${OUTPUT}
      fi
    else
      if [ "${SAME}" ]
      then
        [ "${QUT}" ] || {
          echo "${ASOUND} is identical to a generated asound.conf. No need to update."
        }
      else
        [ "${QUT}" ] || {
          echo "Copying generated asound.conf to ${ASOUND}.gen$$"
        }
        sudo cp /tmp/asound$$ ${ASOUND}.gen$$
      fi
    fi
  fi
  rm -f /tmp/asound$$
fi

exit 0