Shell script for checking checksums

Hello all,

   Before I burn a CD or a DVD, I create an MD5SUM and an SHA1SUM file
on the image. These files - obviously - contain the output of "md5 * >
MD5SUM" and "sha1 * > SHA1SUM".

   Anyhow, a friend of mine told me that his Ubuntu system's md5sum can
automatically check the checksums for him. I - on the other hand - to
check them manually, which is deadly boring.

   So I thought I would change that with the little shell programming I
know. I came up with this:

-----------------------------
#!/bin/sh
MSG="No error(s) encountered! Yay!"
for l in `cat $1 | sed 's/.*(//; s/).*=\ /:/'`
do
        # extract file name
        MD5PATHNAME=${l%%:*}
        MD5CHECKSUM=${l##*:}

        F=`md5 "$MD5PATHNAME" | sed 's/.*(//; s/).*=\ /:/'`
        CHECKSUM=${F##*:}
        if [ "$MD5CHECKSUM" = "$CHECKSUM" ]; then
                echo "$MD5CHECKSUM = $CHECKSUM ($MD5PATHNAME) -- ok!"
        else
                echo "$MD5CHECKSUM != $CHECKSUM ($MD5PATHNAME) -- error!"
                MSG="ERRORS ENCOUNTERED!! Oh, noo!"
        fi

done

echo $MSG
-----------------------------

   This works fine -- as long as there are no spaces in the file name.
Problem is -- I have lots of spaces in lots of file names. I understand
that the problem lays in that "for l in <blah>" treats a space as a file
name separator, and I am guessing that this is a design flaw which can
not be worked around. I did try to modify the sed command to replace the
file name:

This is a file name.txt

   ..with:

This\ is\ a\ file\ name.txt

   ..but that didn't work, so I tried replacing it with:

"This is a file name.txt"

   ..but that didn't work either. So, my first attempt at shell hacking
failed miserably. :-(  So, does anyone have a working solution which
does what I want?

-- 
Kind regards,
Jan Danielsson

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