UUENCODE(1) BSD General Commands Manual UUENCODE(1)
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 flag specified.
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
The uudecode utility transforms uuencoded files (or by default, the standard 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 exe-
cute bits are not retained. The uudecode utility ignores any leading and trailing lines.
The following options are available for uuencode:
-m Use the Base64 method of encoding, rather than the traditional uuencode algorithm.
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 traditional uuencode input. Without -r it has no effect.
Output to output_file instead of any pathname contained in the input data.
-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 security
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 email@example.com
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 -
basename(1), compress(1), mail(1), uucp(1) (ports/net/freebsd-uucp), uuencode(5)
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).
January 27, 2002 BSD