UUENCODE(1) BSD General Commands Manual UUENCODE(1)NAME
uuencode, uudecode, b64encode, b64decode — encode/decode a binary file
uuencode [-m] [-o output_file] [file] name
uudecode [-cimprs] [file ...]
uudecode [-i] -o output_file
b64encode [-o output_file] [file] name
b64decode [-cimprs] [file ...]
b64decode [-i] -o output_file [file]
The uuencode and uudecode utilities are used to transmit binary files
over transmission mediums that do not support other than simple ASCII
data. The b64encode utility is synonymous with uuencode with the -m flag
specified. The b64decode utility is synonymous with uudecode with the -m
The uuencode utility reads file (or by default the standard input) and
writes an encoded version to the standard output, or output_file if one
has been specified. The encoding uses only printing ASCII characters and
includes the mode of the file and the operand name for use by uudecode.
The uudecode utility transforms uuencoded files (or by default, the stan‐
dard input) into the original form. The resulting file is named either
name or (depending on options passed to uudecode) output_file and will
have the mode of the original file except that setuid and execute bits
are not retained. The uudecode utility ignores any leading and trailing
The following options are available for uuencode:
-m Use the Base64 method of encoding, rather than the traditional
Output to output_file instead of standard output.
The following options are available for uudecode:
-c Decode more than one uuencoded file from file if possible.
-i Do not overwrite files.
-m When used with the -r flag, decode Base64 input instead of tradi‐
tional uuencode input. Without -r it has no effect.
Output to output_file instead of any pathname contained in the
-p Decode file and write output to standard output.
-r Decode raw (or broken) input, which is missing the initial and
possibly the final framing lines. The input is assumed to be in
the traditional uuencode encoding, but if the -m flag is used, or
if the utility is invoked as b64decode, then the input is assumed
to be in Base64 format.
-s Do not strip output pathname to base filename. By default
uudecode deletes any prefix ending with the last slash '/' for
The following example packages up a source tree, compresses it, uuencodes
it and mails it to a user on another system. When uudecode is run on the
target system, the file ``src_tree.tar.Z'' will be created which may then
be uncompressed and extracted into the original tree.
tar cf - src_tree | compress |
uuencode src_tree.tar.Z | mail sys1!sys2!user
The following example unpacks all uuencoded files from your mailbox into
your current working directory.
uudecode -c < $MAIL
The following example extracts a compressed tar archive from your mailbox
uudecode -o /dev/stdout < $MAIL | zcat | tar xfv -
SEE ALSObasename(1), compress(1), mail(1), uucp(1) (ports/net/freebsd-uucp),
The uudecode and uuencode utilities appeared in 4.0BSD.
Files encoded using the traditional algorithm are expanded by 35% (3
bytes become 4 plus control information).
BSD January 27, 2002 BSD