NAME
uuencode,
uudecode —
encode/decode a binary file
SYNOPSIS
uuencode |
[-m]
[inputfile]
headername |
uudecode |
[-m]
[-p | -o
outputfile]
[encoded-file ...] |
DESCRIPTION
uuencode and
uudecode are used to transmit
binary files over transmission mediums that do not support other than simple
ASCII data.
The following options are available:
-
-
- -m
- Use base64 encoding. For uuencode, the
historical uuencode algorithm is the default. For
uudecode, by default the encoding is automatically
detected.
-
-
- -o
outputfile
- (uudecode only.)
Send the decoded output data to outputfile. By
default, uudecode uses the
headername recorded in the header of the encoded
data stream.
-
-
- -p
- (uudecode only.)
Write the decoded file to standard output instead of to a file.
uuencode reads
inputfile (or by default
the standard input) and writes an encoded version to (always) the standard
output. The encoding uses only printing ASCII characters suitable for
text-only transport media. The string
headername is
inserted into the output header as the
outputfile to use
at
uudecode time. The header also includes the mode
(permissions) of the file.
uudecode transforms
uuencoded files (or by
default, the standard input) into the original form. The resulting file is
named
headername as recorded in the encoded file, or as
specified by the
-o option, and will have the mode of the
original file except that setuid and execute bits are not retained. If the
-p option is specified, or if the output file name is given
as
/dev/stdout, then the data will be written to the
standard output instead of to a named file.
uudecode ignores
any leading and trailing lines.
The encoded form of the file is expanded by 35%. Every 3 bytes become 4 plus
control information.
EXIT STATUS
The
uudecode and
uuencode utilities exits 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.
tar czf - src_tree | uuencode src_tree.tgz | mail user@example.com
On the other system, if the user saves the mail to the file
temp, the following example creates the file
src_tree.tgz and extracts it to make a copy of the original
tree.
uudecode temp
tar xzf src_tree.tgz
SEE ALSO
gzip(1),
mail(1),
tar(1),
uuencode(5)
STANDARDS
The
uudecode and
uuencode utilities conform
to
IEEE Std 1003.1-2008 (“POSIX.1”).
HISTORY
The
uudecode and
uuencode utilities appeared
in
4.0BSD.
SECURITY CONSIDERATIONS
When using
uudecode with files coming from dubious sources,
always either explicitly pass the
-o option or check the
header (the first line) of the encoded file for safety. Blindly using a
headername from a hostile source can overwrite important
files.