;Set the system path, in a relatively machine-independent manner.
;input
;  p - array of string path components. Each must be a single path component
;      but may start with a + or be an expand_path macro (like <IDL_DEFAULT>)
;      if you want '/stuff/here:+/stuff/there', pass ['/stuff/here','+/stuff/there']
;no output, no return, but sets the !PATH system variable
;
;Notes: This program cleans up each path by converting folder separators (like '/') to
;       the correct local form, and removing consecutive folder separators. It then
;       combines all of them into a single string, calls expand_path() with it,
;       then sets !PATH with the result.
pro set_path,p

  for i=0,n_elements(p)-1 do p[i]=normalize_path(p[i])
  ;Combine them all into one path specifier according to local convention
  s=strjoin(p,path_sep(/search_path))
  ;set the system path
  DEFSYSV, '!PATH', expand_path(s)

end