I've been discovering the power of Larry Wall's "rename" command. Some people think it allows use of the Perl \b (word boundary), but that seems not to be the case. I think I did OK without it. I had to rename files that include dates in the format yyyymmdd as part of the filename by changing that part to the corresponding date in yyyy-mm-dd format. This seems to always work for me: rename 's/(^|[^0-9])((19|20)\d\d)(0\d|1[012])([012]\d|3[01])($|[^0-9])/$1$2-$4-$5$6/g' I'm assuming dates are between 1900-01-01 and 2099-12-31. This cartoon is apropos: https://xkcd.com/1179/ Mike