2.16.2 Wildcard Pathnames

Wildcards are supported in Unix pathnames. If ‘*’ is specified for a part of a pathname, that is parsed as :wild. ‘**’ can be used as a directory name to indicate :wild-inferiors. Filesystem operations treat :wild-inferiors the same as :wild, but pathname pattern matching (e.g. for logical pathname translation, see logical-pathnames) matches any number of directory parts with ‘**’ (see see wildcard-matching.)

‘*’ embedded in a pathname part matches any number of characters. Similarly, ‘?’ matches exactly one character, and ‘[a,b]’ matches the characters ‘a’ or ‘b’. These pathname parts are parsed as pattern objects.

Backslash can be used as an escape character in namestring parsing to prevent the next character from being treated as a wildcard. Note that if typed in a string constant, the backslash must be doubled, since the string reader also uses backslash as a quote:

(pathname-name "foo\\*bar") => "foo*bar"