SGI Freeware 1999 August/SGI Freeware 1999 August.iso/dist/fw_amanda.idb/usr/freeware/libexec/chg-multi.z/chg-multi

Text File | 1999-07-16 | 7.6 KB | 335 lines

#!/bin/sh
#
# Amanda, The Advanced Maryland Automatic Network Disk Archiver
# Copyright (c) 1991-1998 University of Maryland at College Park
# All Rights Reserved.
#
# Permission to use, copy, modify, distribute, and sell this software and its
# documentation for any purpose is hereby granted without fee, provided that
# the above copyright notice appear in all copies and that both that
# copyright notice and this permission notice appear in supporting
# documentation, and that the name of U.M. not be used in advertising or
# publicity pertaining to distribution of the software without specific,
# written prior permission.  U.M. makes no representations about the
# suitability of this software for any purpose.  It is provided "as is"
# without express or implied warranty.
#
# U.M. DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL U.M.
# BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
# WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
# OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
# CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
#
# Author: James da Silva, Systems Design and Analysis Group
#               Computer Science Department
#               University of Maryland at College Park
#

#
# chg-multi.sh - generic tape changer script
#

prefix=/usr/freeware
exec_prefix=${prefix}
libexecdir=/usr/freeware/libexec

pname="chg-multi"

PATH=$libexecdir:/usr/bin:/bin:/usr/sbin:/sbin:/usr/ucb
export PATH

USE_VERSION_SUFFIXES="no"
if test "$USE_VERSION_SUFFIXES" = "yes"; then
    SUF="-2.4.1p1"
else
    SUF=
fi

ourconf=`getconf$SUF changerfile`

MT=/sbin/mt
MTF=-f

# read in some config parameters

if [ \! -f $ourconf ]; then
    echo "<none> $pname: $ourconf does not exist"
    exit 2
fi

firstslot=`awk '$1 == "firstslot" {print $2}' $ourconf 2>/dev/null`
if [ "$firstslot" = "" ]; then
    echo "<none> $pname: firstslot not specified in $ourconf"
    exit 2
fi

lastslot=`awk '$1 == "lastslot" {print $2}' $ourconf 2>/dev/null`
if [ "$lastslot" = "" ]; then
    echo "<none> $pname: lastslot not specified in $ourconf"
    exit 2
fi

nslots=`expr $lastslot - $firstslot + 1`

gravity=`awk '$1 == "gravity" {print $2}' $ourconf 2>/dev/null`
if [ "$gravity" = "" ]; then
    echo "<none> $pname: gravity not specified in $ourconf"
    exit 2
fi

needeject=`awk '$1 == "needeject" {print $2}' $ourconf 2>/dev/null`
if [ "$needeject" = "" ]; then
    echo "<none> $pname: needeject not specified in $ourconf"
    exit 2
fi

multieject=`awk '$1 == "multieject" {print $2}' $ourconf 2>/dev/null`
if [ "$multieject" = "" ]; then
    echo "<none> $pname: multieject not specified in $ourconf"
    multieject=0
#    exit 2
fi

ejectdelay=`awk '$1 == "ejectdelay" {print $2}' $ourconf 2>/dev/null`
if [ "$ejectdelay" = "" ]; then
    echo "<none> $pname: ejectdelay not specified in $ourconf"
    ejectdelay=0
fi

ourstate=`awk '$1 == "statefile" {print $2}' $ourconf 2>/dev/null`
if [ "$ourstate" = "" ]; then
    echo "<none> $pname: statefile not specified in $ourconf"
    exit 2
fi

# read in state: only curslot and curloaded at the present time

curslot=`awk '$1 == "curslot" {print $2}' $ourstate 2>/dev/null`
if [ "$curslot" = "" ]; then
    curslot=$firstslot
fi

curloaded=`awk '$1 == "curloaded" {print $2}' $ourstate 2>/dev/null`
if [ "$curloaded" = "" ]; then
    curloaded=0
fi


# process the command-line

# control vars to avoid code duplication: not all shells have functions!
usage=0
checkgravity=0
ejectslot=0
loadslot=0
slotempty=0

if [ $# -ge 1 ]; then command=$1; else command="-usage"; fi

case "$command" in

-info) # return basic information about changer

    backwards=`expr 1 - $gravity`
    echo $curslot $nslots $backwards
    exit 0
    ;;

-reset) # reset changer

    checkgravity=0
    loadslot=1
    newslot=$firstslot

    # XXX put changer-specific reset here, if applicable
    ;;

-eject) # eject tape if loaded

    checkgravity=0
    loadslot=0
    newslot=$curslot
    ejectslot=1

    if [ $curloaded -eq 0 ]; then
        echo $curslot "slot already empty"
        exit 1
    fi
    ;;

-slot)    # change to slot

    checkgravity=1
    loadslot=1

    slotparm=$2
    case "$slotparm" in
    [0-9]*)
        newslot=$slotparm
        if [ \( $newslot -gt $lastslot \) -o \
             \( $newslot -lt $firstslot \) ]; then
            echo $newslot "no slot $newslot: legal range is" \
                "$firstslot ... $lastslot"
            exit 1
        fi
        ;;
    current)
        newslot=$curslot
        ;;
    first)
        newslot=$firstslot
        ;;
    last)
        newslot=$lastslot
        ;;
    next|advance)
        newslot=`expr $curslot + 1`
        if [ $newslot -gt $lastslot ]; then
            newslot=$firstslot
        fi
        if [ $slotparm = advance ]; then
            loadslot=0
        fi
        ;;
    prev)
        newslot=`expr $curslot - 1`
        if [ $newslot -lt $firstslot ]; then
            newslot=$lastslot
        fi
        ;;
    *)
        echo "<none> bad slot name \"$slotparm\""
        exit 1
        ;;
    esac
    ;;
*)
    usage=1
    ;;
esac


if [ $usage -eq 1 ]; then
    echo "<none> usage: $pname {-reset | -slot [<slot-number>|current|next|prev|advance]}"
    exit 2
fi


# check for legal move

if [ \( $checkgravity -eq 1 \) -a \( $gravity -ne 0 \) ]; then
    if [ \( $newslot -lt $curslot \) -o \( "$slotparm" = "prev" \) ]
    then
        echo "$newslot cannot go backwards in gravity stacker"
        exit 1
    fi
fi

# get tape device name

device=`awk '$1 == "slot" && $2 == '$newslot' {print $3}' $ourconf 2>/dev/null`
if [ "$device" = "" ]; then
    echo "$newslot $pname: slot $newslot device not specified in $ourconf"
    exit 2
fi

# check if load needs an eject first

if [ \( $needeject -eq 1 \) -a \( $loadslot -eq 1 \) -a \
     \( $curloaded -eq 1 \) -a \( $newslot -ne $curslot \) ]; then
    ejectslot=1
fi


if [ $ejectslot -eq 1 ]; then    # eject the tape from the drive

    # XXX put changer-specific load command here, if applicable

    curloaded=0        # unless something goes wrong
    slotempty=0

    # generically, first check that the device is there

    if [ ! -c $device ]; then
        echo "$newslot $device: not a device file"
        exit 2
    fi

    # if multiple eject is required, do it now
    if [ $multieject -eq 1 ]; then
        loopslot=$curslot
        while [ $loopslot -lt $newslot ]; do
            $MT $MTF $device offline >/dev/null 2>&1
            if [ $? -ne 0 ]; then
                echo "$newslot $device: unable to change slot $loopslot"
                exit 2
            fi
            loopslot=`/usr/bin/expr $loopslot + 1`
        done
    fi

    # second, try to unload the device
    $MT $MTF $device offline >/dev/null 2>&1
    if [ $? -ne 0 ]; then
        #
        # XXX if the changer-specific eject command can distinguish
        # betweeen "slot empty" and more serious errors, return 1
        # for the first case, 2 for the second case.  Generically,
        # we just presume an error signifies an empty slot.
        #
        slotempty=1
    else
        sleep $ejectdelay
    fi
fi

if [ $loadslot -eq 1 ]; then    # load the tape from the slot

    # XXX put changer-specific load command here, if applicable

    curloaded=1        # unless something goes wrong
    slotempty=0

    # generically, first check that the device is there

    if [ ! -c $device ]; then
        echo "$newslot $device: not a device file"
        exit 2
    fi

    # second, try to rewind the device
    $MT $MTF $device rewind >/dev/null 2>&1
    if [ $? -ne 0 ]; then
        #
        # XXX if the changer-specific load command can distinguish
        # betweeen "slot empty" and more serious errors, return 1
        # for the first case, 2 for the second case.  Generically,
        # we just presume an error signifies an empty slot.
        #
        slotempty=1
        curloaded=0
    fi
fi

# update state

echo "# multi-changer state cache: DO NOT EDIT!" >  $ourstate
echo curslot $newslot                  >> $ourstate
echo curloaded $curloaded             >> $ourstate

# return slot info

if [ $slotempty -eq 1 ]; then
    echo "$newslot slot is empty"
    exit 1
fi

if [ "$command" = -slot -a "$slotparm" = advance ]; then
    device=/dev/null
fi

echo $newslot $device

exit 0