An AmigaDOS pattern matching string is a combination of alphanumeric
characters and a series of special token characters.  These token
characters are part of the ASCII character set and they denote such things
as string matching wildcards, string repetitions, and string negation.
Pattern matching strings can use parentheses to delimit pattern matching
substrings.


?    The question mark matches any single character.  For example,
     the pattern matching string "A?B" matches any string that is
     three letters long, that starts with an "A" and ends with a
     "B".


#    The number sign matches strings containing zero or more
     repetitions of the expression that immediately follows the # in
     the pattern matching string.  For example, the pattern matching
     string "#A" matches any string that consists of one or more of
     the "A" character.  The pattern matching string "#?" matches
     any non-NULL string.  The # can apply to entire substrings
     delimited by parentheses.  For example, the pattern string
     "#(AB)" matches any string consisting of one or more
     repetitions of the substring "AB" (AB, ABAB, ABABAB...).


%    Matches the NULL string.


|    This is the OR symbol.  This matches strings that contain the
     expressions on either side of the OR sign.  The expressions and
     the OR symbol need to be enclosed in parentheses.  For example,
     the pattern matching string "(A|B)" matches the string "A"
     or the string "B".  The pattern matching string A(B|%|C)
     matches the strings "AB", "A", and "AC".


~    The tilde negates the expression that follows it.  All
     strings that do not match the expression that follows the tilde
     will match the expression with the tilde.  For example, the
     pattern matching string "~(#?.info)" matches any string that
     does not match the string "#?.info" (does not end with the
     substring ".info").


*    The star is provided as an synonym to "#?".  This is an
     option which can be turned on.  Note that the star can not be
     used by itself on all non-FileSystem devices, like a logical
     device name assigned to a directory on a file system.  For
     example:
                Assign A: dh0:tmp
                cd a:
                list *

     will produce an error.  The SetStar.c example at the end of this
     article is a small, stand-alone utility to turn this option on
     and off.


[]   All characters within brackets indicate a character class.  Any
     character in the character class qualifies.  Within a character
     class, a character range can be indicated by specifing the start
     and stop character, separated with a minus sign.  Note that
     character classes are case sensitive.  If character classes are
     to be used in a case insensitive form, they should be translated
     to uppercase.  Here are some example:

       [ACF]#?         matches strings starting with `A', `C', or `F'
       [A-D]#?         matches strings starting with `A', `B', `C', or `D'
       [~ACF]#?        matches strings not starting with `A', `C', or `F'


'    The quote character neutralizes the special meaning of a
     special character.  Here are some examples:

       '#'? matches only the literal string "#?"
       '?(A|B|C|%)'# matches the literal strings "?#", "?A#", "?B#", "?C#"
       " matches '


()   Parentheses group special characters.  The expression within the
     parentheses is a subpattern.