Determine the next binlog file for a given binlog filename.

binlog.erl

-module(binlog).
-compile(export_all).

current_log() -> "db-000004.bin".

%% binlog:next_log(binlog:current_log()).
%% binlog:next_log("db-000004.bin").
next_log("db-" ++ TmpA) ->
    "nib." ++ TmpB = lists:reverse(TmpA),
    TmpC = list_to_integer(lists:reverse(TmpB)) + 1,
    lists:concat(["db-", string:right(integer_to_list(TmpC), erlang:length(TmpB), $0), ".bin"]).

test_a_() ->
    [
        next_log("db-000000.bin") == "db-000001.bin",
        next_log("db-000004.bin") == "db-000005.bin",
        next_log("db-000008.bin") == "db-000009.bin",
        next_log("db-000009.bin") == "db-000010.bin",
        next_log("db-000304.bin") == "db-000305.bin",
        next_log("db-003009.bin") == "db-003010.bin"
    ].