$rindex(<characters> <text>)

• The <characters> argument is a dword. This is different from most functions.
• <characters> may contain any number of different characters. If you want to include the space character, enclose it in double quotes. If you want to include the double quote character, put some other character before the double-quote.
• If the first character in <characters> is the caret (“^”), then the list of <characters> is negated; <characters> includes all characters that are NOT after the tilde.
• Counting begins after the first space after <characters>. If multiple spaces separate <characters> and <text>, only the first such space is the separator; further spaces are part of <text> for the purpose of counting.
• The return value is the number of initial characters in <text> that proceed the LAST INSTANCE of any characters specified by <characters>; the index of the last instance of any character in <characters> in the string <text>, counting from zero.
• If none of the characters in <characters> appears in <text> (a failed search), then -1 is returned.

It used to be common to use $rindex() to find a character in a string so that you could extract the parts of the string before and after the character. This is more easily done by $before() and $after() though.

  -1   no character in <characters> was found in <text>
> -1   index to last instance of something in <characters> in <text>

This function originally appeared in ircII-2.1.3

$rindex(abc hello there bob)         returns 14
$rindex(abc   hello there bob)       returns 16
 (because of the spaces after 'c' and before 'h')
$rindex(xyz hello there bob)         returns -1
$rindex()                            returns the empty string