bsd man page for uuencode

UUENCODE(5)							File Formats Manual						       UUENCODE(5)

NAME
       uuencode - format of an encoded uuencode file

DESCRIPTION
       Files  output  by  uuencode(1C) consist of a header line, followed by a number of body lines, and a trailer line.  Uudecode(1C) 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 6 characters "begin ".  The word begin is followed by a mode (in octal), and a  string
       which names the remote file.  A space separates the three items in the header line.

       The  body  consists  of	a number of lines, each at most 62 characters long (including the trailing newline).  These consist of a character
       count, followed by encoded characters, followed by a newline.  The character count is a single printing character, and represents an  inte-
       ger, 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 sub-
       tracting 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.

SEE ALSO
       uuencode(1C), uudecode(1C), uusend(1C), uucp(1C), mail(1)

7th Edition							   May 15, 1985 						       UUENCODE(5)