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Preparing a CD that displays proper file names whether it is mounted on a Unix system or on a Windows box requires little more than the proper set of arguments to the mkisofs command and software that knows how to work with ISO images. In this week's column, we look at a script that prepares a multi-use ISO image from files in a selected directory.
To understand this script, assume that we have a directory that contains a series of subdirectories, each of which contains the files associated with a particular software product that we might want to write to a CD for distribution to our customers.
We will use the select command to create a menu of the subdirectories from which the user will select the product that he wants to write to CD. Each subdirectory is named after the product that it contains. Once the user has selected a particular product, the script uses the mkisofs command with a particular set of options to create an ISO image that can subsequently be written to a CD. The options used in this particular script are explained below:
-r sets the uid and gid to 0
-U allows "untranslated" filenames, violating the ISO9660 standards, but
providing the flexibility that we need to accommodate filenames with more
than one dot
-iso-level specifies the particular ISO level that we want to use
-A specifies text to be written into the volume header
-V specifies volume ID to be written into the master block
-o specifies the name of our output file (i.e., the ISO file we are creating)
-copyright specifies the name of the file containing the copyright
Numerous other options are available with the mkisofs command. You will have to read the man page to learn about all the possibilities.
The completed script looks like this:
#!/bin/bash
#
# mkCD
# identify location of product directories
prodDir=/data/delivery
cd $prodDir
# ask user to select product install files to burn to CD
echo
echo "Select product for ISO image:"
select PRODUCT in `ls`; do
break
done
# Move to product directory
cd $PRODUCT 2>/dev/null || (echo "ERROR: Not a directory $dir"; exit 1)
APPLID=`head -1 Copyright`
# Have user verify files to be written to ISO image
ls -l
ans=`ckyorn -p "Files OK?"`
case $ans in
[Yy]*) echo;;
[Nn]*) echo "Exiting."
exit 1
;;
*) echo "Exiting. Please try again."
exit 1
;;
esac
# remove previous iso files from /tmp
if [ -f /tmp/$PRODUCT.iso ]; then
ans=`ckyorn -p "remove existing iso file?> "`
case $ans in
[Yy]*) rm /tmp/$PRODUCT.iso;;
[Nn]*) mv /tmp/$PRODUCT.iso /tmp/$PRODUCT.iso$$;;
esac
fi
# create the ISO image
mkisofs -r -U -iso-level 2 -A "$APPLID" -sysid "Boson Ltd" \
-V "$PRODUCT" -o /tmp/$PRODUCT.iso *
# show user the file that was created
ls -l /tmp/$PRODUCT.iso
Here's the output from a sample running of the script:
# ./mkCD
Select product for ISO image:
1) Product1
2) Product2
3) Product3
#? 2
total 52396
-rw-r--r-- 1 root other 121 Nov 20 16:45 Copyright
-rw-r--r-- 1 root other 918 Nov 20 16:44 Manifest
-rw-r--r-- 1 root other 186 Nov 20 16:46 config
-rwxr-xr-x 1 root other 18129064 Nov 20 16:52 config.new.tar.Z
-rwxr-xr-x 1 root other 8644824 Nov 20 16:51 install.full.tar.Z
-rw-r--r-- 1 root other 92 Nov 20 16:46 parms
-rw-r--r-- 1 root other 92 Nov 20 16:46 readme
-rw-r--r-- 1 root other 296 Nov 20 16:46 registration.txt
Files OK? [y,n,?,q] y
remove existing iso file?> [y,n,?,q] y
Warning: creating filesystem that does not conform to ISO-9660.
38.09% done, estimate finish Mon Nov 20 16:55:16 2006
76.13% done, estimate finish Mon Nov 20 16:55:16 2006
Total translation table size: 0
Total rockridge attributes bytes: 829
Total directory bytes: 0
Path table size(bytes): 10
Max brk space used 8000
13136 extents written (25 Mb)
-rw-r--r-- 1 root other 26902528 Nov 20 16:55 /tmp/Product2.iso
You can verify the labels you used during the creation of the ISO file by using the labelit command. Notice that we use the -F hsfs parameter to specify the type of file we are asking about.
# labelit -F hsfs /tmp/Product2.iso
CD-ROM is in ISO 9660 format
System id: Boson Ltd
Volume id: Product2
Volume set id:
Publisher id:
Data preparer id:
Application id: Boson Ltd Product 2
Copyright File id: Copyright
Abstract File id:
Bibliographic File id:
Volume set size is 1
Volume set sequence number is 1
Logical block size is 2048
Volume size is 13136
The warning about ISSO 9660 is generated due to our use of the -U flag. The ISO Level 2 option allows filename with up to 31 characters. The * in the mkisofs command says which files (i.e., all in the current directory) are to be incorporated into the ISO image.
Verifying the content of the CD
Once the CD has been created (I used ImgBurn freeware), you can verify that the contents of the CD look proper on both Unix and Windows systems.
Checking on Windows, my CD contents looked like this:
> dir D:
Volume in drive D is Product2
Volume Serial Number is 2ACA-4CE6
Directory of D:\
11/20/2006 04:45 PM 121 Copyright
11/20/2006 04:44 PM 918 Manifest
11/20/2006 04:46 PM 186 config
11/20/2006 04:52 PM 18,129,064 config.new.tar.Z
11/20/2006 04:51 PM 8,644,824 install.full.tar.Z
11/20/2006 04:46 PM 92 parms
11/20/2006 04:46 PM 92 readme
11/20/2006 04:46 PM 296 registration.txt
8 File(s) 26,775,593 bytes
0 Dir(s) 0 bytes free
Checking on Solaris, the files look basically the same:
bash-2.03# ls -l /cdrom/product2
total 52301
-r--r--r-- 1 root root 121 Nov 20 16:45 Copyright
-r--r--r-- 1 root root 918 Nov 20 16:44 Manifest
-r--r--r-- 1 root root 186 Nov 20 16:46 config
-r-xr-xr-x 1 root root 18129064 Nov 20 16:52 config.new.tar.Z
-r-xr-xr-x 1 root root 8644824 Nov 20 16:51 install.full.tar.Z
-r--r--r-- 1 root root 92 Nov 20 16:46 parms
-r--r--r-- 1 root root 92 Nov 20 16:46 readme
-r--r--r-- 1 root root 296 Nov 20 16:46 registration.txt
Creating CDs that look proper whether they are mounted on a Unix or Windows system is easy, but I like to use a script so that I don't have to remember which options to use with the mkisofs command.
