I have been working on a script that executes on a number of different operating systems. As a result I was trying to set a variable or perhaps variable array depending on the OS. I tried the following using eval and such but so far have not had any luck. Is there a way to do something like the following.

DF="df -h | sed -e :a -e '$!N;s/\n / /;ta' -e 'P;D' | /usr/xpg4/bin/grep -ivE "filesystem|$FSIGNORE" | awk '{ print $6" "$5}'"

Later in the script do this:

$DF | while read LINE; do ...

I tried a host of different things, like putting eval into the variable and escaping the quotes but it just did not seem to work correctly. Any ideas, or am I better off writing the output of the command to a temp file and reading from the file?

Thanks in advance.