Created
June 25, 2012 23:49
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-module(general_lib). | |
-compile(export_all). | |
-define(SECRET, "SOMETEXTHERE"). | |
time_as_string() -> | |
{MegaSeconds, Seconds, MicroSeconds} = erlang:now(), | |
integer_to_list(MegaSeconds) ++ integer_to_list(Seconds) ++ integer_to_list(MicroSeconds). | |
time_as_seconds() -> | |
time_as_seconds(erlang:now()). | |
time_as_seconds(Time) -> | |
calendar:datetime_to_gregorian_seconds(calendar:now_to_local_time(Time)). | |
local_time_as_seconds(Time) -> | |
calendar:datetime_to_gregorian_seconds(Time). | |
to_upper(S) -> lists:map(fun char_to_upper/1, S). | |
to_lower(S) -> lists:map(fun char_to_lower/1, S). | |
char_to_upper(C) when C >= $a, C =< $z -> C bxor $\s; | |
char_to_upper(C) -> C. | |
char_to_lower(C) when C >= $A, C =< $Z -> C bxor $\s; | |
char_to_lower(C) -> C. | |
% Generates a random binary UUID. | |
uuid() -> | |
to_string(generate_uuid()). | |
generate_uuid() -> | |
v4(crypto:rand_uniform(1, round(math:pow(2, 48))) - 1, crypto:rand_uniform(1, round(math:pow(2, 12))) - 1, crypto:rand_uniform(1, round(math:pow(2, 32))) - 1, crypto:rand_uniform(1, round(math:pow(2, 30))) - 1). | |
v4(R1, R2, R3, R4) -> | |
<<R1:48, 4:4, R2:12, 2:2, R3:32, R4: 30>>. | |
% Generate a random string of given length | |
generate_random_string(Length) -> | |
generate_random_string(Length, "abcdefghijkmnpqrstuvwxyz23456789"). | |
generate_random_string(Length, AllowedChars) -> | |
lists:foldl(fun(_, Acc) -> | |
[lists:nth(random:uniform(length(AllowedChars)), AllowedChars)] ++ Acc end, [], lists:seq(1, Length)). | |
% Returns a string representation of a binary UUID. | |
to_string(U) -> | |
lists:flatten(io_lib:format("~8.16.0b-~4.16.0b-~4.16.0b-~2.16.0b~2.16.0b-~12.16.0b", get_parts(U))). | |
% Returns the 32, 16, 16, 8, 8, 48 parts of a binary UUID. | |
get_parts(<<TL:32, TM:16, THV:16, CSR:8, CSL:8, N:48>>) -> | |
[TL, TM, THV, CSR, CSL, N]. | |
% Converts a UUID string in the format of 550e8400-e29b-41d4-a716-446655440000 | |
% (with or without the dashes) to binary. | |
to_binary(U)-> | |
convert(lists:filter(fun(Elem) -> Elem /= $- end, U), []). | |
% Converts a list of pairs of hex characters (00-ff) to bytes. | |
convert([], Acc)-> | |
list_to_binary(lists:reverse(Acc)); | |
convert([X, Y | Tail], Acc)-> | |
{ok, [Byte], _} = io_lib:fread("~16u", [X, Y]), | |
convert(Tail, [Byte | Acc]). | |
% Use this with models to always get the string version | |
to_list(Binary) when is_binary(Binary) -> | |
binary_to_list(Binary); | |
to_list(Val) -> | |
Val. | |
to_float(Float) when erlang:is_float(Float) -> | |
Float; | |
to_float(Float) -> | |
% well there is no is_string so I guess this one just goes last | |
string:to_float(Float). | |
floor(X) -> | |
T = erlang:trunc(X), | |
case (X - T) of | |
Neg when Neg < 0 -> T - 1; | |
Pos when Pos > 0 -> T; | |
_ -> T | |
end. | |
ceiling(X) -> | |
T = erlang:trunc(X), | |
case (X - T) of | |
Neg when Neg < 0 -> T; | |
Pos when Pos > 0 -> T + 1; | |
_ -> T | |
end. | |
% Be careful with this, it is O(N) | |
index_of(Item, List) -> index_of(Item, List, 1). | |
index_of(_, [], _) -> not_found; | |
index_of(Item, [Item|_], Index) -> Index; | |
index_of(Item, [_|Tl], Index) -> index_of(Item, Tl, Index+1). |
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