Function: org-file-name-concat
org-file-name-concat is a function alias for file-name-concat, defined
in fileio.c.
Signature
(org-file-name-concat DIRECTORY &rest COMPONENTS)
Documentation
Append COMPONENTS to DIRECTORY and return the resulting string.
Elements in COMPONENTS must be a string or nil. DIRECTORY or the non-final elements in COMPONENTS may or may not end with a slash -- if they don't end with a slash, a slash will be inserted before concatenating.