[https://core.tcl.tk/tcllib/doc/trunk/embedded/www/tcllib/files/modules/base64/base64.html%|%base64], a [Tcllib] module, provides commands for encoding and decoding binary data in [base64].  In Tcl [Tcl 8.6%|%8.6], it has largely been superceded by `[binary]`, which also provides base64 encoding and decoding.



** Sub-modules **

    [uuencode]:   

    [yencode]:   

    [http://en.wikipedia.org/wiki/Ascii85%|%ascii85]:   



** Documentation **

   [http://core.tcl.tk/tcllib/doc/trunk/embedded/www/tcllib/files/modules/base64/base64.html%|%official reference] (alternates [http://tcllib.sourceforge.net/doc/base64.html%|%1], [http://docs.activestate.com/activetcl/8.5/tcllib/base64/base64.html%|%2]:   



** See Also **

   [Base 64 encode/decode]:   shows an example of this [Tcllib] module at work.

   [http://code.activestate.com/recipes/117247/%|%Inline GIF image into code] ,[Cookbook]:   an example of processesing [GIF]s using base64

   [Simple Base64 Gif encoder]:   another example



** Obsolete Information **

The following information is no longer particularly relevant.  It remains for
historical purposes.

The base64 which is part of tcllib is slow, and catastrophically memory-hungry
for large (on the order of a megabyte or more) sources.  The memory disaster
results from what [Donal Fellows] reports as a bug to SourceForge
[http://sourceforge.net/bugs/?func=detailbug&bug_id=131523&group_id=10894]. He
provided a patch as well
[http://sourceforge.net/patch/?func=detailpatch&patch_id=103709&group_id=10894].
Although it doesn't help performance significantly in the cases of interest to
[Cameron Laird], a simple fix for the memory woe is to overide base64::decode
with a version which substitutes

======
set length [string length $string]
for {set ii 0} {$ii < $length} {incr ii} {
    set char [string range $string $ii $ii]
    ...  
======

for 

======
foreach char [split $string {}] {
    ...
======

''Note: in the current version in tcllib (version 2.2.1 of base64), this code
has been replaced by''

======
binary scan $string c* X  
foreach x $X { 
======


<<categories>> base64