One previously seen operation that returns a different value in a list context is <STDIN> . As described earlier, <STDIN> returns the next line of input in a scalar context. However, in a list context, it returns all remaining lines up to end of file. Each line is returned as a separate element of the list. For example:
@a = <STDIN>; # read standard input in a list context
If the person running the program types three lines, then presses CTRL-D (to indicate "end of file"), the array ends up with three elements. Each element will be a string that ends in a newline, corresponding to the three newline-terminated lines entered.
 Some systems use CTRL-Z to indicate end of file, while others use it to suspend a running process.