OpenBSD manual page server

NAME

uuencode, uudecode, b64encode, b64decode — encode/decode a binary file

SYNOPSIS

DESCRIPTION

The uuencode and uudecode utilities are used to transmit binary files over transmission mediums that do not support formats other than printable ASCII data. b64encode and b64decode are equivalent to running uuencode and uudecode respectively with the -m flag specified.

uuencode reads file (or by default, the standard input) and writes an encoded version to the standard output, or to output_file if it 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.

uudecode 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 set-user-ID and execute bits are not retained. uudecode ignores any leading and trailing lines.

The options for uuencode are as follows:

-m

Use the Base64 method of encoding, rather than the traditional uuencode algorithm.

-o output_file

Output to output_file instead of standard output.

The options for uudecode are as follows:

-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.

-o output_file

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 reasons.

EXIT STATUS

The uuencode, uudecode, b64encode, and b64decode utilities exit 0 on success, and >0 if an error occurs.

EXAMPLES

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 user@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 -

SEE ALSO

basename(1), compress(1), mail(1), uuencode(5)

STANDARDS

The uudecode and uuencode utilities are compliant with the IEEE Std 1003.1-2008 (“POSIX.1”) specification.

The flags [-ciprs] are extensions to that specification.

The use of the -o flag for uuencode and the -m flag for uudecode are also extensions to that specification.

HISTORY

The uudecode and uuencode utilities appeared in 4.0BSD.

BUGS

Files encoded using the traditional algorithm are expanded by 35% (3 bytes become 4 plus control information).