Re: How to generate 64-character length lines in base64?

MIME::Base64 is a very small module, and the encode method is particularly small, since pack() does most of the work. They use pack to create a uuencoded string, then tr// to translate from the uuencode charset to the Base64 charset: Copying the source, then, with a few minor modifications

sub b6464 {
    my $orig=shift;
    my $string = pack("u",$orig);
    $string =~ s/^.//mg;
    $string =~ s/\n//g;
    # use tr to translate from UUE to Base64
    $string =~ tr|` -_|AA-Za-z0-9+/|;
    # fix padding at the end
    my $padding = (3 - length($orig) % 3) % 3;
    $string =~ s/.{$padding}$/'=' x $padding/e if $padding;
    # break string into lines of 64 chars or less
    $string =~ s/(.{1,64})/$1\n/g;
    return $string;
}
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Re^2: How to generate 64-character length lines in base64? by rmichael (Initiate) on Apr 03, 2013 at 11:46 UTC
I've got a bit of time now, and am looking at this again. Thank you for your help!	[reply]
Re^2: How to generate 64-character length lines in base64? by rmichael (Initiate) on Apr 03, 2013 at 12:58 UTC
Sorry to ask another total newbie question, but could you please link to the source you mentioned you copied with modifications? I'm not at all familiar with the Perl source tree or build process. To me, it appears `MIME::Base64::encode` method is a reference to the `MIME::Base64::encode_base64` method (an external subroutine)? I do not see the XS `encode_base64` method using pack(). What am I missing? I'm code reading on GitHub, sorry for external links; can the Monks CPAN link shortcuts do source code with line number? https://github.com/gisle/mime-base64/blob/master/Base64.pm#L16 https://github.com/mirrors/perl/blob/blead/cpan/MIME-Base64/Base64.xs#L97 Thanks again!	[reply] [d/l] [select]
Re^3: How to generate 64-character length lines in base64? by kschwab (Vicar) on Apr 03, 2013 at 13:42 UTC
I started with the "Pure Perl" (i.e., no XS-C code) version of the module here: Mime::Base64::Perl Then, clicked the "source" link there, which leads to this: Mime::Base64::Perl Source	[reply]
Re^4: How to generate 64-character length lines in base64? by rmichael (Initiate) on Apr 03, 2013 at 14:15 UTC
Super, thanks again.	[reply]