`which'
-------

which("FILENAME")
     :: This returns the path name for the FILENAME which `load()' will
     read.

RETURN
     path name

FILENAME
     filename (path name) or 0

   * This function searches directory trees according to the same
     procedure as `load()' will do.  Then, returns a string, the path
     name to the file if the named file exists; 0 unless otherwise.

   * For details of searching procedure, refer to the description about
     `load()'.

   * On Windows one has to use `/' as the separator of directory names.

     [0] which("gr");
     ./gb/gr
     [1] which("/usr/local/lib/gr");
     0
     [2] which("/usr/local/lib/asir/gr");
     /usr/local/lib/asir/gr

References
     *Note `load': load.

