ddv

#!/bin/bash

# ddv - `dd' with periodic status check
#
# ver 1.00 (09/01/2013) : Initial Release

# Copyright (c) 2013, Tomoaki Shimoyama
# All rights reserved.
#
# [The BSD 2-Clause License]
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are
# met:
#
#  * Redistributions of source code must retain the above copyright notice,
#    this list of conditions and the following disclaimer.
#
#  * Redistributions in binary form must reproduce the above copyright notice,
#    this list of conditions and the following disclaimer in the
#    documentation and/or other materials provided with the distribution.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
# IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
# TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
# PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
# HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

DEFAULT_INTERVAL=180

if [ -z "$DDV" ] ; then
    INTERVAL=$DEFAULT_INTERVAL
else
    INTERVAL=$( expr $( expr $DDV + 0 2> /dev/null ) + 0 )
    if [ $INTERVAL -le 0 ] ; then INTERVAL=$DEFAULT_INTERVAL ; fi
fi

sendsig() {
    DD_PID=
    CONTINUE=true
    while [ $CONTINUE = true ] ; do
        sleep $INTERVAL
        if [ -z "$DD_PID" ] ; then
            DD_PID=$( ps al \
                | grep -w dd \
                | grep -v grep \
                | grep -w $1 \
                | sed -e "s/  */ /g" \
                | cut -d " " -f 3 \
                )
        fi
        if [ ! -z "$DD_PID" ] ; then
            kill -USR1 $DD_PID > /dev/null 2>&1
            if [ $? -eq 0 ] ; then
                echo ; date
            else
                DD_PID=
                CONTINUE=false
            fi
        else
            CONTINUE=false
        fi
    done
}

sendsig $$ &
SENDSIG_PID=$!

fin() {
    kill $SENDSIG_PID
}
trap fin EXIT

dd $@