Kernighans large earthquake problem: Difference between revisions

8/27/1883 Krakatoa 8.8

5/18/1980 MountStHelens 7.6

</pre>

=={{header|Prolog}}==

{{works with|SWI Prolog}}

Example command line: <code>swipl kernighans_earthquake.pl earthquake.txt</code>.

<lang prolog>:- initialization(main, main).

process_line(Line):-

split_string(Line, "\s\t", "\s\t", [_, _, Magnitude_string]),

read_term_from_atom(Magnitude_string, Magnitude, []),

Magnitude > 6,

!,

writef('%w\n', [Line]).

process_line(_).

process_stream(Stream):-

read_line_to_string(Stream, String),

String \= end_of_file,

!,

process_line(String),

process_stream(Stream).

process_stream(_).

process_file(File):-

open(File, read, Stream),

process_stream(Stream),

close(Stream).

main([File]):-

process_file(File),

!.

main(_):-

swritef(Message, 'File argument is missing\n', []),

write(user_error, Message).</lang>

{{out}}

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