Good morning, the file contains "8.25F, \n". I notice a strange behavior with this line: sed -i -r 's/([0-9])F([,; \]\}\)])/\1\2/g' file while I'm expecting to get "8.25, \n", the content is not changed. To get the expected substitution, I must use: sed -i -r 's/([0-9])F([,; \}\)])/\1\2/g' file as if it is not legal to use the escaped character ']'. Thanks for your time; I apologize if I'm wrong. Best Regards Massimo Masotti - Italy