Question

I’m newbie with Objective-C and Cocoa. But i develop simple mail client. And i have some problem with encoding.
MIME headers may look like this:

From: =?UTF-8?B?eWVsbA==?= <[e-mail]>
Subject: =?UTF-8?B?0J/RgNC+0LLQtdGA0LrQsCDRgdCy0Y/Qt9C4?=

or like this:

Subject: =?KOI8-R?B?zc7F?=
From: user <[e-mail]>

or like this:

Subject: test subject
From: testname <[e-mail]>

So as you see, if it’s not ASCII string, it’s have following format:

=?{charset}?{B or Q}?{Base64 or Quoted-printable encoded string}?=

So after base64 decoding we know charset of this string.
Is there analog of PHP function iconv(), for example. Or how to make coversion between different charsets in Objective-C?

Answer 1

You could use these two NSString methods

- (BOOL)getBytes:(void *)buffer maxLength:(NSUInteger)maxBufferCount usedLength:(NSUInteger *)usedBufferCount encoding:(NSStringEncoding)encoding options:(NSStringEncodingConversionOptions)options range:(NSRange)range remainingRange:(NSRangePointer)leftover

- (id)initWithData:(NSData *)data encoding:(NSStringEncoding)encoding