Look up pulseaudio sink-input index by property

Question

The output of both pactl list sink-inputs and pacmd list-sink-inputs contains a Properties section:

Properties:
    media.name = "ALSA Playback"
    application.name = "ALSA plug-in [snapclient]"
    native-protocol.peer = "UNIX socket client"
    native-protocol.version = "29"
    application.process.id = "6393"
    application.process.user = "root"
    application.process.host = "xxxxxx"
    application.process.binary = "snapclient"
    application.language = "C"
    application.process.machine_id = "8dadf95c2f504864bc0f8b3ab149cbe0"
    application.process.session_id = "c4"
    module-stream-restore.id = "sink-input-by-application-name:ALSA plug-in [snapclient]"

I am wondering if there is a way to directly look up the index of a sink-input by either the application.process.id or application.process.binary, without resorting to parsing the many lines of output of the aforementioned commands or writing a separate C program.

Answer 1

Some commands also accept the unique name instead of the id, but the ones you are trying to use seem to not be able to do so.. probably because the name is not unique and there could be mulitple matches. You need to parse it yourself. This is what I came up with:

pacmd list-sink-inputs |
tr '\n' '\r' |
perl -pe 's/.*? *index: ([0-9]+).+?application\.name = "([^\r]+)"\r.+?(?=index:|$)/\2:\1\r/g' |
tr '\r' '\n'

perl -pe is like sed, just better. This basically matches [anything] [index]: [id] [anything] [application.name] = [name] [anything] and formats the output to something like

"speech-dispatcher":166
"SoX":407
"Clementine":413

Which you then can grep or sed.

Maybe you want to adjust application\.name to something more suitable to you.

Answer 2

Although it does parse the output and doesn't yet do any matching for the id you may be looking for, this method will provide a way, with some modifications, to get that information by sink id:

pactl list sink-inputs | while read -r line ; do

  #echo "Processing ${line}"
  echo $line | grep -oP 'Sink Input #\K[^$]'
  echo $line | grep -oP 'application.process.id = "\K[^"]+'
  echo $line | grep -oP 'application.process.binary = "\K[^"]+'

done

Answer 3

Here's a short solution to OP's question:

$ cat pulse-get-sink-input-for-pid
#!/bin/bash
if [ $# -ne 1 ]; then >&2 echo Need PID; exit 1; fi
export pid=$1
pactl list sink-inputs | perl -nle '/Sink Input #(\d+)/ and $si = $1; /application.process.id.*?(\d+)/ and ($1 == $ENV{pid}) and print "$si"'

Answer 4

The very long, easy to understand, maintainable way to do it (using application.process.binary)

Result

ffmpeg | 3
firefox-esr | 24
firefox-esr | 58
vlc | 43

Bash script

str="$(pacmd list-sink-inputs)"

list1=$(printf '%s' "$str" | grep 'index: ')
list2=$(printf '%s' "$str" | grep 'application.process.binary = "')

arr1=()
arr2=()

while read line; do
    arr1+=("${line:7}")
done <<< "$list1"

while read line; do
    arr2+=("${line:30:-1}")
done <<< "$list2"

for index in ${!arr1[@]}; do
    s1="${arr1[index]}"
    s2="${arr2[index]}"

    echo "$s2 | $s1"
done

Another way to do it (a bit more obscure)

str="$(pacmd list-sink-inputs)"

arr1=($(printf '%s' "$str" | grep 'index: ' | rev | cut -d' ' -f 1 | rev))
arr2=($(printf '%s' "$str" | grep 'application.process.binary' | cut -d'"' -f 2))

for index in ${!arr1[@]}; do
    s1="${arr1[index]}"
    s2="${arr2[index]}"

    echo "$s2 | $s1"
done

And finally, the shortest solution I found :

str="$(pacmd list-sink-inputs)"

paste -d\| \
<(printf '%s' "$str" | grep 'application.process.binary' | cut -d'"' -f 2) \
<(printf '%s' "$str" | grep 'index: ' | rev | cut -d' ' -f 1 | rev)