world.Base64Decode

MUSHclient script function (Method) — introduced in version 3.22

Takes a base-64 encoded string and decodes it.

Prototype

VARIANT Base64Decode(BSTR Text);

Data type meanings

Description

Takes a base-64 encoded string (eg. "TmljayBHYW1tb24=") and decodes it. The string may contain space characters (including carriage-return/newline) which will be removed.

The string to be decoded must contain valid base-64 characters, and must be a multiple of 4 characters long (once spaces are removed), or a NULL variant will be returned.

The valid base-64 characters are:

'A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P',
'Q','R','S','T','U','V','W','X','Y','Z','a','b','c','d','e','f',
'g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v',
'w','x','y','z','0','1','2','3','4','5','6','7','8','9','+','/'

Also, '=' is used as a padding character if the original text to be encoded was not exactly a multiple of 3 characters long.

Because of the way strings are stored this will not work with strings which have nulls in them (hex 00), however see below for a work-around for Lua.

VBscript example

world.note world.Base64Decode ("TmljayBHYW1tb24=")

Jscript example

world.note (world.Base64Decode ("TmljayBHYW1tb24="));

PerlScript example

$world->note ($world->Base64Decode ("TmljayBHYW1tb24="));

Python example

world.note (world.Base64Decode ("TmljayBHYW1tb24="))

Lua example

Note (Base64Decode ("TmljayBHYW1tb24="))

-- or, as described in the notes:

Note (utils.base64decode ("TmljayBHYW1tb24="))

Lua notes

In MUSHclient version 3.57 onwards you can also use

decoded_string = utils.base64decode (s)

This works the same as described above, however it will correctly handle strings with the null (hex 00) character in them.

This function works a bit differently if it encounters "bad" data:

* Characters not in the set shown above are silently ignored

* If the source string is not a multiple of four characters, the string is still processed, however up to the last 3 bytes will not be returned.

Return value

The decoded string, or a NULL variant if the input string was not a multiple of 4 characters in length, once spaces were removed, or did not contain the valid base-64 characters listed above.

Note that due to the way strings are represented internally, it is not possible for the decoded string to contain the NULL character (hex 0x00) and be returned correctly.