Each of the strings a and b must either be single
characters, or else the (two or more digit) base-ten numeric representation
of a single
character. $replace() evaluates to string c, but with
each instance of character a replaced by character b.
Treats all of the words as a single word.
(It evaluates to the string words, with all of the
blanks replaced with a non-printable control character.)
This function is useful in several different circumstances:
When comparing two multi-word strings, as in: $equal ($quote (string1) $quote (string2))
To combine several words as one argument to the
include directive, as in:
include file.i $(cnum) $quote(conference description)
To supply a multi-word string to a function that
specifically expects a $quote'd string, such as