Thanks for responding jeffa.

I tried your solution with a for..do loop, but it did not work. It appeared to be running for a small amount of time, but did not do any edits. I tried to run it from ksh and bash, and tried to specify ksh and bash in place of sh, but got no joy.

I thought about trying to do this in xargs, but I too had problems getting it correct. That is why I thought perl might be better.

There are more details in the back story of how I got to this point, but I wasn't sure it was needed for the perl discussion.