# If you'd like to omit non-matching lines from the result; add ';d' to the end of the expression.
sed -E 's/((([A-Za-z]{3,9}:(?:\\/\\/)?)(?:[-;:&=\+\$,\w]+@)?[A-Za-z0-9.-]+(:[0-9]+)?|(?:www.|[-;:&=\+\$,\w]+@)[A-Za-z0-9.-]+)((?:\\/[\+~%\\/.\w-_]*)?\??(?:[-\+=&;%@.\w_]*)#?(?:[\w]*))?)/$1/gim;t' <<< "ftp://eau.ww.eesd.gov.calgary/home/smith/budget.wk1
gopher://gopher.voa.gov
http://www.apple.com/index.html
https://www.cuug.ab.ca:8001/~branderr/csce.html"
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for SED, please visit: https://www.gnu.org/software/sed/manual/html_node/The-_0022s_0022-Command.html