RE: Problems with hdiutil

Thanks for the pointer on the workaround.  Creating as a sized sparse image instead of UDRW allows it to work correctly.  It’s a bit more work, but as long as it works I’ll be satisfied.

 

In case anyone is interested, here is how I would edit the script I sent out previously (to demonstrate the UDRW conversion bug) to work.  Note that creating a sparse image will append .sparseimage to the name unless it already has that extension, and the –size field can be a minimum of 512k.

 

David Litwin

BigFix, Inc.

 

#!/bin/sh

 

echo "Create the source ImageDir"

mkdir ImageDir

echo "This welcome text will *not* get wiped out when we use a sparse image" > ImageDir/Flim.txt

echo

 

echo "Calculate the size of the source dir in kilobytes"

usageLine=`du -s ImageDir`

imageSize=`expr "$usageLine" : '\([0123456789]*\)[ ]*[^ ]*$'`

# sparse images have a minimum size of 512k

if [ `expr $imageSize \< 512` ]; then

    echo "ImageDir size is ${imageSize}k, using minimum of 512k"

    imageSize=512

else

    echo "ImageDir size is ${imageSize}k"

fi

echo

 

echo "Create the sparse image"

echo hdiutil create -volname "hdiutil-bug" -layout NONE -fs 'HFS+' -type "SPARSE" -size ${imageSize}k -ov "Writable.dmg.sparseimage"

hdiutil create -volname "hdiutil-bug" -layout NONE -fs 'HFS+' -type "SPARSE" -size ${imageSize}k -ov "Writable.dmg.sparseimage"

echo

 

echo "Mount the sparse image and copy in files"

mountLine=`hdiutil attach "Writable.dmg.sparseimage" | tail -n 1`

disk=`expr "$mountLine" : '\([^ ]*\).*$'`

volLoc=`expr "$mountLine" : '[^ ]*[^\/]*\(.*\)$'`

cd ImageDir

tar cf - * | (cd "$volLoc" ; tar xfBp -)

cd ..

hdiutil detach -force "$disk"

echo

 

echo "Create the compressed read only image from the writable sparse image"

echo hdiutil convert "Writable.dmg.sparseimage" -format UDZO -o "Compressed.dmg" -ov -imagekey zlib-level=9

hdiutil convert "Writable.dmg.sparseimage" -format UDZO -o "Compressed.dmg" -ov -imagekey zlib-level=9

echo

 

echo "Mount and check the contents of the sparse image"

mountLine=`hdiutil attach "Writable.dmg.sparseimage" | tail -n 1`

disk=`expr "$mountLine" : '\([^ ]*\).*$'`

volLoc=`expr "$mountLine" : '[^ ]*[^\/]*\(.*\)$'`

hexdump -C "$volLoc/Flim.txt"

hdiutil detach -force "$disk"

echo

 

echo "Mount and check the contents of the compressed read only image"

mountLine=`hdiutil attach "Compressed.dmg" | tail -n 1`

disk=`expr "$mountLine" : '\([^ ]*\).*$'`

volLoc=`expr "$mountLine" : '[^ ]*[^\/]*\(.*\)$'`

hexdump -C "$volLoc/Flim.txt"

hdiutil detach -force "$disk"

echo