Function: f-absolute?
f-absolute? is a function alias for file-name-absolute-p, defined in
fileio.c.
Signature
(f-absolute? FILENAME)
Documentation
Return t if FILENAME is an absolute file name.
On Unix, absolute file names start with /. In Emacs, an absolute
file name can also start with an initial ~ or ~USER component,
where USER is a valid login name.