mailcap-replace-in-string

mailcap-replace-in-string is a compiled Lisp function in `mailcap.el'.

(mailcap-replace-in-string STRING REGEXP NEWTEXT &optional LITERAL)

Replace all matches for REGEXP with NEWTEXT in STRING.
If LITERAL is non-nil, insert NEWTEXT literally. Return a new
string containing the replacements.
This is a compatibility function for different Emacsen.