write-to-string

(write-to-string object &key escape readably pretty circle right-margin miser-width lines pprint-dispatch length level base radix case gensym array)

Returns object's printed representation as a string. Without keywords it is the readable (prin1) form, an alias for prin1-to-string; each keyword binds the matching printer control variable around the one print, exactly as for write (:escape nil gives the princ form). #'write-to-string as a value takes the keywords too ((apply #'write-to-string x keys)).