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. Foruudecode, by default the encoding is automatically detected. -ooutputfile- (
uudecodeonly.) Send the decoded output data to outputfile. By default,uudecodeuses the headername recorded in the header of the encoded data stream. -p- (
uudecodeonly.) 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
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.