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digitalmars.D.learn - How decode encoded Base64 to string text?

reply Marcone <marcone email.com> writes:
I can encode "Helo World!" to Base64 and get "TWFyY29uZQ==", but 
if I try to decode "TWFyY29uZQ==" I can not recovery "Helo 
World!" but [77, 97, 114, 99, 111, 110, 101]. How can I recover 
"Helo World!" when decode? Thank you.


import std;

void main(){
	string text = "Helo World!";

	auto encoded = Base64.encode(text.representation);
	auto decoded = Base64URL.decode("TWFyY29uZQ==");

	writeln(encoded); // prints: "TWFyY29uZQ=="
	writeln(to!string(decoded)); // prints: [77, 97, 114, 99, 111, 
110, 101] but I want to print: "Helo World!"
}
Nov 08 2019
next sibling parent reply Aldo <aldocd4 outlook.com> writes:
On Friday, 8 November 2019 at 11:46:44 UTC, Marcone wrote:

 I can encode "Helo World!" to Base64 and get "TWFyY29uZQ==", 
 but if I try to decode "TWFyY29uZQ==" I can not recovery "Helo 
 World!" but [77, 97, 114, 99, 111, 110, 101]. How can I recover 
 "Helo World!" when decode? Thank you.

 ...
 	writeln(to!string(decoded));
 ...


Casting to string seems to work: writeln(cast(string) decoded);
Nov 08 2019
parent Marcone <marcone email.com> writes:
On Friday, 8 November 2019 at 12:36:37 UTC, Aldo wrote:

 On Friday, 8 November 2019 at 11:46:44 UTC, Marcone wrote:

 I can encode "Helo World!" to Base64 and get "TWFyY29uZQ==", 
 but if I try to decode "TWFyY29uZQ==" I can not recovery "Helo 
 World!" but [77, 97, 114, 99, 111, 110, 101]. How can I 
 recover "Helo World!" when decode? Thank you.

 ...
 	writeln(to!string(decoded));
 ...


 Casting to string seems to work: writeln(cast(string) decoded);


Thank you very much! It is working fine!
Nov 08 2019
prev sibling parent Simen =?UTF-8?B?S2rDpnLDpXM=?= <simen.kjaras gmail.com> writes:
On Friday, 8 November 2019 at 11:46:44 UTC, Marcone wrote:

 I can encode "Helo World!" to Base64 and get "TWFyY29uZQ==", 
 but if I try to decode "TWFyY29uZQ==" I can not recovery "Helo 
 World!" but [77, 97, 114, 99, 111, 110, 101]. How can I recover 
 "Helo World!" when decode? Thank you.


 import std;

 void main(){
 	string text = "Helo World!";

 	auto encoded = Base64.encode(text.representation);
 	auto decoded = Base64URL.decode("TWFyY29uZQ==");

 	writeln(encoded); // prints: "TWFyY29uZQ=="
 	writeln(to!string(decoded)); // prints: [77, 97, 114, 99, 111, 
 110, 101] but I want to print: "Helo World!"
 }


What Aldo said - Base64 operates on ubyte[], which a string is 
not (it's immutable(char)[]). There's also assumeUTF 
(https://dlang.org/library/std/string/assume_utf.html) which may 
document your code a bit better than a simple cast, but it does 
the same thing inside.

The reason Base64 operates on ubyte[] is to be able to encode 
arbitrary data, while the reason to!string doesn't convert your 
ubyte[] to a readable string is that not all ubyte[] are valid 
strings, and displaying arbitrary data as if it were a string is 
sure to cause problems.

--
   Simen
Nov 08 2019