# If you'd like to omit non-matching lines from the result; add ';d' to the end of the expression.
sed -E 's/(<img.*?)(src=")(.*?\\/)([^\\/]*")(.*?)(alt=")(.*?")([^>]*>)/src="" data-path="\1" data-img="\2"/;t' <<< "<img class=\"alignnone size-medium wp-image-18\" src=\"http://localhost/wp-content/uploads/2015/02/300x149-jquerymobile.jpg\" alt=\"\" width=\"300\" height=\"149\">"
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