chop (%key_hash = map { split /\s*[|]\s*/,$_,2 } grep (!/^$/,<KEY_FH>));
  ^                             ^  ^  ^    ^ ^            ^      ^
  |                             |  |  |    | |            |      |
  |                             |  |  |    | |            |      + - File handle
  |                             |  |  |    | |            + - Let only non-empty file lines pass
  |                             |  |  |    | + - Split string into two parts
  |                             |  |  |    + - Default scalar containing a file line
  |                             |  |  + - Zero or more whitespaces
  |                             |  + - Vertical bar as only member in character set
  |                             + - Zero or more whitespaces
  + - Should be 'chomp' to remove the trailing newlines