Added sidetone toggle script 'st'

st

@@ -0,0 +1,51 @@
+#!/usr/bin/env sh
+
+delay=$1
+usage='Usage: st [delay_in_milliseconds]\n\nThis utility will toggle sidetone for your primary audio input device.\nDelay argument is optional -- default: 1\n'
+# Sanity check
+### Set delay to 1 if unspecified
+if [ $# -eq 0 ]; then
+    delay=1
+fi
+
+### Check if pavucontrol is available
+if (! type pactl &>/dev/null); then
+    printf "ERROR 12: 'pactl' command not found!\n\n  This command is part of PulseAudio Volume Control, which may commonly be found in your distribution's repository as 'pavucontrol'.\n  Please install and try again."
+    exit 12
+fi
+
+### Check if delay value >1
+if [ $delay -lt 1 ]; then
+    echo "ERROR 13: Delay can not be less than 1!" >&2
+    printf "\n$usage"
+    exit 13
+fi
+
+### Check if delay value is an integer (no extra characters)
+case $delay in
+    ''|*[!0-9]*) 
+        echo "ERROR 14: Delay value must be an unsigned integer!" >&2 ;
+        printf "\n$usage" ;
+        exit 14 ;;
+esac
+# End sanity check
+
+
+if (pactl list | grep module-loopback) 2>&1 >/dev/null; then
+    pactl unload-module module-loopback
+    echo "Sidetone: OFF"
+    exit 0
+else
+    pactl load-module module-loopback latency_msec=${delay} >/dev/null || exit 1
+    if [ $delay -gt 1 ]; then
+        printf "Sidetone: ON\tDelay: ${delay}ms\n"
+    else
+        echo "Sidetone: ON"
+    fi
+    exit 0
+fi
+
+
+echo "ERROR 3: We don't know WTF happened!" >&2
+exit 3
+