Hi, sorry a bit off-topic, sed -e 's/\(<[^ ]*>\)\([ ]*\)\(<[^ ]*>\)/\3\2\1/g' GNU Linux is cool Linux GNU cool is I don't know why $ echo "GNU linux is cool" | sed -e 's/\(<[^ ]*>\)\([ ]*\)\(<[^ ]*>\)/\3\2\1/g' GNU linux is cool It doesn't work. Thanks for any suggestions, Best regards,