View source for Convert a file to/from Base64

* One of the use of base64 file is to convert binary files into text files and, for example, send them via mail.
* This is an example of what you get if you watch inside a base64 file

 <code>UEsDBAoAAAAAAEZcOFMAAAAAAAAAAAAAAAAIABwAdGVzdERpci9VVAkAA5ObTWHPn01hdXgLAAEE
 6AMAAAToAwAAUEsDBAoAAAAAAERcOFMgMDo2BgAAAAYAAAARABwAdGVzdERpci90ZXN0MS50eHRV
 VAkAA4+bTWGIm01hdXgLAAEE6AMAAAToAwAAaGVsbG8KUEsDBAoAAAAAAElcOFOQoBAeBwAAAAcA
 AAARABwAdGVzdERpci90ZXN0Mi50eHRVVAkAA5qbTWGTm01hdXgLAAEE6AMAAAToAwAAaGVsbG8y
 ClBLAQIeAwoAAAAAAEZcOFMAAAAAAAAAAAAAAAAIABgAAAAAAAAAEADtQQAAAAB0ZXN0RGlyL1VU</code>

=== Encode a file into new file Base64 ===

* The Linux/MacOSX way of doing such conversion is:

 $> base64 foo.dat > foo.dat.b64

* In Cuis you do:

 inFile _ '/home/p/foo.dat'.
 file64 _ '/home/p/foo.dat.b64'. 
 rs1 _ inFile asFileEntry readStream useBytes.
 rs2 _ file64 asFileEntry forceWriteStream .
 Base64MimeConverter mimeEncode: rs1 to: rs2.  
 rs1 close. rs2 close.

=== Decode a Base64 file into a new file ===

* You can do this in Linux/MacOSX with

 $> base64 -d foo.dat.b64 > foo.dat 

* In Cuis you do:

 file64 _ '/home/p/foo.dat.b64'. 
 outFile _ '/home/p/foo.dat'.
 rs1 _ file64 asFileEntry readStream.
 rs2 _ outFile asFileEntry forceWriteStream useBytes.
 Base64MimeConverter mimeDecode: rs1 to: rs2.  
 rs1 close. rs2 close.