A good place to start is http://www.emacswiki.org/emacs/RegularExpression http://www.emacswiki.org/emacs/RegularExpression, followed by https://www.gnu.org/soft

A good place to start is http://www.emacswiki.org/emacs/RegularExpression http://www.emacswiki.org/emacs/RegularExpression, followed by https://www.gnu.org/software/emacs/manual/html_node/emacs/Regexps.html https://www.gnu.org/software/emacs/manual/html_node/emacs/Re... and https://www.gnu.org/software/emacs/manual/html_node/emacs/Regexp-Replace.html https://www.gnu.org/software/emacs/manual/html_node/emacs/Re.... They're more references than tutorials though; unfortunately I'm not aware of any comprehensive tutorials on the subject.