Tests whether a file is writable.
A pathname, string or file-stream, designating a file.
Checks if file is writable. Note that this checks the properties of the file, so trying to write to the file may still fail if the file is non-writable for other reasons, for example if it is opened for writing by another program.
CL-USER 44 > file-writable-p (sys:lispworks-file "private-patches/load.lisp")
LispWorks Reference Manual - 20 Jul 2006