uuencode
uuencode
[‚yü′yü·in‚kōd]uuencode
(communications)Uuencoded data starts with a line of the form
begin
where
Uuencode repeatedly takes in a group of three bytes, addingtrailing zeros if there are less than three bytes left. These24 bits are split into four groups of six which are treated asnumbers between 0 and 63. Decimal 32 is added to each numberand they are output as ASCII characters from 32 (space) to32+63 = 95 (underscore). Each group of sixty outputcharacters (corresponding to 45 input bytes) is output as aseparate line preceded by an 'M' (ASCII code 77 = 32+45). Atthe end of the input, if there are N output characters leftafter the last group of sixty and N>0 then they will bepreceded by the character whose code is 32+N. Finally, a linecontaining just a single space is output, followed by onecontaining just "end".
Sometimes each data line has an extra dummy character added toavoid problems which mailers that strip trailing spaces.These characters are ignored by uudecode.
Despite using this limited range of characters, there arestill some problems encountered when uuencoded data passesthrough certain old computers. The worst offenders arecomputers using non-ASCII character sets such as EBCDIC.
Base 64 encoding is probably now more commonly used thanuuencode.