[NaLug] [mini-HOWTO] utilizzare i tasti per il controllo del volume sulle tastiere con tasti speciali

[ncrfgs a tin.it]

#!/bin/bash
#
#  ctrltgl.sh
#
#  Copyright (c) 2008 Fergus Incoronato
#
#  This program is free software; you can redistribute it and/or modify
#  it under the terms of the GNU General Public License as published by
#  the Free Software Foundation; either version 2 of the License, or
#  (at your option) any later version.
#
#  This program is distributed in the hope that it will be useful,
#  but WITHOUT ANY WARRANTY; without even the implied warranty of
#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#  GNU General Public License for more details.
#
#  You should have received a copy of the GNU General Public License
#  along with this program; if not, write to the Free Software
#  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
02111-1307, #  USA.
#

info() {
	echo "=======> $1"
}

warning() {
	info "WARNING: $1" >&2
}

error() {
	info "ERROR: $1" >&2
}

interrupted() {
	echo ""
	error "Interrupted."
	exit 1
}

parse_options(){
	if (($#<4)); then
		echo "`basename $CTRLTGL_COMMAND`: not enough arguments"
		exit 1
	elif (($#>4)); then
		echo "`basename $CTRLTGL_COMMAND`: too many arguments"
		exit 1
	fi

	while [ "$1" ]; do
		case $1 in
			-c|--control)
				if [ ! "$2" ]; then
					echo "`basename
$CTRLTGL_COMMAND`: option $1 requires an argument" exit 1
				fi
				CTRLTGL_CONTROL="$2"
				CTRLTGL_OVFILE="$2.state"
				shift ;;
			-d|--directory)
				if [ ! "$2" ]; then
					echo "`basename
$CTRLTGL_COMMAND`: option $1 requires an argument" exit 1
				fi
				CTRLTGL_WORK_DIR="$2"
				shift ;;
			*)
				echo "`basename $CTRLTGL_COMMAND`:
invalid option $1" exit 1 ;;
		esac
		shift
	done
}

check_exists() {
	if [ ! -e "$1" ]; then
		error "'$1' does not exist."
		exit 1
	fi
}

check_is_directory() {
	if [ ! -d "$1" ]; then
		error "'$1' is not a directory."
		exit 1
	fi
}

check_is_regular() {
	if [ ! -f "$1" ]; then
		error "'$1' is not a regular file."
		exit 1
	fi
}

check_is_writable() {
	if [ ! -w "$1" ]; then 
		error "'$1' is not writable."
		exit 1
	fi
}

check_is_readable() {
	if [ ! -r "$1" ]; then
		error "'$1' is not readable."
		exit 1
	fi
}

main() {
	local OVFILE_SIZE NUMID MIN MAX OLD_VOL CUR_VOL NEW_VOL


	parse_options "$@"


	check_exists "$CTRLTGL_WORK_DIR"
	check_is_directory "$CTRLTGL_WORK_DIR"
	check_is_writable "$CTRLTGL_WORK_DIR"
	check_is_readable "$CTRLTGL_WORK_DIR"
	check_exists "$CTRLTGL_WORK_DIR/$CTRLTGL_OVFILE"
	check_is_regular "$CTRLTGL_WORK_DIR/$CTRLTGL_OVFILE"
	check_is_writable "$CTRLTGL_WORK_DIR/$CTRLTGL_OVFILE"
	check_is_readable "$CTRLTGL_WORK_DIR/$CTRLTGL_OVFILE"


	OVFILE_SIZE="`find "$CTRLTGL_WORK_DIR/$CTRLTGL_OVFILE" -printf
"%s\n"`"

	if ((OVFILE_SIZE<1)) || ((OVFILE_SIZE>4)); then
		error "'$CTRLTGL_WORK_DIR/$CTRLTGL_OVFILE' size is
incompatible with allowed values." exit 1
	fi      


	NUMID="`amixer controls | grep "$CTRLTGL_CONTROL" | cut -d , -f
1 | cut -d = -f 2`" MIN="`amixer cget numid=$NUMID | grep ";" | cut
-d , -f 4 | cut -d = -f 2`" MAX="`amixer cget numid=$NUMID | grep ";" |
cut -d , -f 5 | cut -d = -f 2`"


	OLD_VOL="`cat "$CTRLTGL_WORK_DIR/$CTRLTGL_OVFILE"`"

	if [ "$OLD_VOL" ]; then
		if ((OLD_VOL<MIN)); then
			error "'$CTRLTGL_WORK_DIR/$CTRLTGL_OVFILE'
content is lesser than minimum allowed value." exit 1
		elif ((OLD_VOL>MAX)); then
			error "'$CTRLTGL_WORK_DIR/$CTRLTGL_OVFILE'
content is greater than maximum allowed value." exit 1
		fi
	fi


	CUR_VOL="`amixer cget numid="$NUMID" | grep : | cut -d , -f 2`"

	if ((CUR_VOL==0)) && [ "$OLD_VOL" ]; then
		NEW_VOL="$OLD_VOL"
		CUR_VOL=""
	else
		NEW_VOL="0"
	fi


	amixer cset numid="$NUMID" "$NEW_VOL"

	sed "1s|^$OLD_VOL$|$CUR_VOL|" -i
"$CTRLTGL_WORK_DIR/$CTRLTGL_OVFILE"


	exit 0
}

trap "interrupted" SIGHUP SIGINT SIGQUIT SIGTERM

readonly CTRLTGL_VERSION="0.1.0"
readonly CTRLTGL_COMMAND="$0"

main "$@"

# End of file
-- 
Value your freedom, or you will lose it, teaches history.
``Don't bother us with politics,'' respond those who don't
want to learn.

 -- Richard M. Stallman
    http://www.gnu.org/philosophy/linux-gnu-freedom.html
-------------- parte successiva --------------
Un allegato non testuale è stato rimosso....
Nome:        signature.asc
Tipo:        application/pgp-signature
Dimensione:  197 bytes
Descrizione: non disponibile
Url:         http://nalug.net/pipermail/ml/attachments/20080725/7384900a/attachment.bin