first commit

vol

@@ -0,0 +1,82 @@
+#!/bin/bash
+
+MIX=amixer
+declare -i LO=0     # Minimum volume; try 10 to avoid complete silence
+declare -i HI=100   # Maximum volume; try 95 to avoid distortion
+declare -i ADJ=3    # Volume adjustment step size
+
+usage ()
+{
+	echo "Usage: `basename $0` [ - | + | N ]" >&2
+	echo "  where N is a whole number between $LO and $HI, inclusive." >&2
+	exit 1
+}
+
+# Zero or one argument
+[ $# -le 1 ] || usage
+
+# Argument must be one of: empty, -, +, number
+[[ $1 == ?(-|+|+([0-9])) ]] || usage
+
+ARG="$1"
+
+# Number argument
+if [[ $ARG == +([0-9]) ]]; then
+	# Strip leading zeros
+	while [[ $ARG == 0+([0-9]) ]]; do
+		ARG=${ARG#0}
+	done
+	# Must be between LO and HI
+	(( ARG >= LO && ARG <= HI )) || usage
+fi
+
+EXE=$(which $MIX)
+if [ -z "$EXE" ]; then
+	echo "Error: $MIX not found. Try \"sudo apt-get install alsa-utils\" first." >&2
+	exit 2
+fi
+
+GET=$($EXE cget numid=1)
+declare -i MIN=-4000 
+#declare -i MIN=$(echo $GET | /bin/grep -E -o -e ',min=[^,]+' | /bin/grep -E -o -e '[0-9-]+')
+declare -i MAX=$(echo $GET | /bin/grep -E -o -e ',max=[^,]+' | /bin/grep -E -o -e '[0-9-]+')
+declare -i VAL=$(echo $GET | /bin/grep -E -o -e ': values=[0-9+-]+' | /bin/grep -E -o -e '[0-9-]+')
+
+echo $MIN $MAX $VAL
+
+if (( MIN >= MAX || VAL < MIN || VAL > MAX )); then
+	echo "Error: could not get the right values from $MIX output." >&2
+	exit 3
+fi
+
+declare -i LEN=0
+(( LEN = MAX - MIN ))
+
+declare -i ABS=0
+(( ABS = VAL - MIN ))
+
+declare -i PCT=0
+(( PCT = 100 * ABS / LEN ))
+
+if [ ! -z "$ARG" ]; then
+
+	declare -i OLD=$PCT
+
+	if [[ "$ARG" == "+" ]]; then
+		(( PCT += ADJ ))
+	elif [[ "$ARG" == "-" ]]; then
+		(( PCT -= ADJ ))
+	else
+		PCT=$ARG
+	fi
+
+	if [[ "$PCT" != "$OLD" ]]; then
+		(( ABS = PCT * LEN / 100 ))
+		(( VAL = MIN + ABS ))
+		$EXE -q cset numid=1 -- $VAL
+	fi
+fi
+
+echo $PCT
+exit 0
+