uuencode

UUENCODE(5)                   File Formats Manual                  UUENCODE(5)

NAME
       uuencode - format of an encoded uuencode file

DESCRIPTION
       Files  output  by  uuencode(1)  consist of a header line, followed by a
       number of body lines, and a trailer line.  The uudecode(1) command will
       ignore  any lines preceding the header or following the trailer.  Lines
       preceding a header must not, of course, look like a header.

       The header line is distinguished by having the first  5  characters  be
       begin  followed  by  a space, or else a hyphen and either base64 or en-
       coded or both (also separated with a hyphen).  The base64  option  says
       the  file  has  been encoded using base64.  The encoded option says the
       output file name has been base64 encoded.  It  is  never  encoded  with
       traditional  uuencoding.   This is a GNU extension.  These are followed
       by a mode (in octal), and a string which names the  remote  file.   The
       mode  is  separated from the begin clause and the file name by a single
       space character.

   Traditional uuencoding
       The traditional uuencoded file body consists of a number of lines, each
       at most 62 characters long (including the trailing newline). These con-
       sist of a character count letter, followed by the  encoded  characters,
       followed  by a newline.  The character count is a single printing char-
       acter, and represents an integer, the number of bytes the rest  of  the
       line  represents.   Such  integers are always in the range from 0 to 63
       and can be determined by subtracting the  character  space  (octal  40)
       from the character.

       Groups  of  3  bytes  are stored in 4 characters, 6 bits per character.
       All are offset by a space to make the characters  printing.   The  last
       line  may  be  shorter  than the normal 45 bytes.  If the size is not a
       multiple of 3, this fact can be determined by the value of the count on
       the  last  line.   Extra garbage will be included to make the character
       count a multiple of 4.  The body is terminated by a line with  a  count
       of zero.  This line consists of one ASCII space.

       The trailer line consists of end on a line by itself.

   base64 encoding
       base64 encoded files follow the specified format for the body, but also
       include a begin-base64 header and a trailer line of four = characters.

EXAMPLES
            begin-base64-encoded 644 VE9ETw==
       This introduces a base64 encoded file named, TODO with  that  name  en-
       coded using base64 encoding.

            begin-encoded 644 5$]$3P``
       This  introduces an encoded file named, TODO with that name encoded us-
       ing uuencoding.  The encoding is a lot less  friendly.   Please  prefer
       base64 encoding.

CONFORMING TO
       IEEE Std 1003.1, plus extensions

       The  -encoded  suffix to the begin header line is a GNU extension.  Re-
       cipients must have the GNU uudecode program to decode them.

SEE ALSO
       uuencode(1), uudecode(1), base64(1GNU)

HISTORY
       The uuencode file format appeared in BSD 4.0 .

                                                                   UUENCODE(5)