uuencode(C)                   06 January 1993                    uuencode(C)


 Name

    uuencode, uudecode - encode/decode a binary file for transmission via
    mail

 Syntax

    uuencode [ source_filename ] remote_filename

    uudecode [ -s ] [ file ]

 Description

    The uuencode and uudecode commands are used to convert a binary file
    to/from ASCII characters for transfer via uucp(C) or other electronic
    mail delivery systems.  This combination can be used over indirect mail
    links or other non-binary transmission media.

    source_filename is the name of the file which is to be uuencoded. uuen-
    code reads from the standard input as the default if this filename is not
    given.

    remote_filename is the name the file will be given at the remote site
    after it has been uudecoded. You must always supply this argument. It is
    generally a good idea to give the file to be uuencoded a different name
    on a remote site to prevent the accidental overwriting of existing files.
    You may also find it preferable to use a relative pathname rather than an
    absolute one.

    The uuencoded form of the binary file is written to the standard output.
    This output may be redirected to a file for later transmission, or it may
    be piped directly into the mail command (see ``Examples'' below).

    The remote filename together with the mode (as an octal number) of the
    source file are encoded into the output as a one line header with the
    format:

       begin mode remote_filename

    The uuencoded file ends with a one line footer which has the format:

       end

    The uuencoded file is an ordinary text file and can be edited by any text
    editor to change the mode or remote_filename in the header line.

    uudecode reads a uuencoded file (or standard input as default), and
    recreates the original binary file, giving it the mode and name
    remote_filename specified in the header line. If the -s argument is
    specified, the decoded file is written to standard output rather than to
    the filename (remote_filename) specified in the header line.

 Examples

    uuencode can send an encoded file to a user on another system by piping
    it through the mail(C) command:

       uuencode  source_fname  remote_fname | mail  system!user.

    The recipient of the file only needs to run uudecode to recover the
    binary (uudecode discards any extra lines at the beginning or end of the
    file).

    The following example encodes the binary file usr/bin/prog as the ASCII
    file uuencoded. This is to be restored at the remote site as the binary
    file their_prog:

       uuencode  /bin/prog  their_prog  > uuencoded

    The binary file, their_prog, is recovered from uuencoded at the remote
    site using uudecode:

       uudecode uuencoded

    If you wished to give the decoded binary a different filename and path,
    you could edit the header line of the file uuencoded, or you could
    redirect the output of uudecode:

       uudecode  -s  uuencoded  > /usr/local/bin/our_prog

    You would also use the -s option to redirect output if you do not have
    write permission on the encoded destination directory.

    To counteract the expansion produced by uuencode, use compress(C) to
    compress the binary before using uuencode, and uncompress(C) after
    uudecode to recover the file:

       sum  prog
       compress  prog
       uuencode  prog.Z  their_prog.Z  > LS

       uudecode  LS
       uncompress  their_prog.Z
       sum  their_prog

    sum(C) is used here to check that the source and remote binaries are the
    same.  If the checksums are different, it is likely that the binary has
    been corrupted.

 See also

    mail(C), compress(C), sum(C), uucp(C) and uux(C).

 Restrictions

    The file is expanded by 35% (3 bytes become 4 plus control information)
    causing it to take longer to transmit.

    The user on the remote system who is invoking uudecode (often uucp) must
    have write permission on the destination directory specified in the
    header line of the encoded file. Also, the path to the destination direc-
    tory for the decoded file must exist.  (The -s option to uudecode may be
    used to circumvent these restrictions.)