UUDeview - a powerful decoder for binary files
uudeview [options] [@file] file(s)
is a smart decoder for attachments that you have received in
encoded form via electronic mail or from the usenet. It is similar to the
(1) command, yet with more comfort and flexibility.
supports the uuencoding, xxencoding, Base64, yEncoding
encoding methods, and is able to handle split-files (which
have been sent in multiple parts) as well as multiple files at once, thus
greatly simplifying the decoding process. Usually, you will not have to
manually edit files to prepare them for decoding.
After invoking uudeview,
it will scan all given files for encoded data,
sort them and their parts and then present you with the list of files that
seem like they can be decoded properly. You can then pick files individually
- Disables interactivity. After scanning the files and sorting everything
out, the program will not promt you for whether a file shall be decoded or
not, but batch-decodes all available files. This is the default when
reading from standard input.
- Autorename option. If a target file already exists, and this option is
given, a dot and a unique sequence number is appended to the file name.
I.e., foo.gif becomes foo.gif.1 if decoded a second time.
- An alternative incarnation of autorename. If a target file already exists,
an underscore and a unique sequence number is inserted into the filename
before the first dot, i.e., foo.gif becomes foo_1.gif.
- Gives the OK to overwrite existing files when decoding. In interactive
mode, the default is to prompt the user whether to overwrite, rename or
skip the file. This option takes precedence over -a. In
non-interactive mode (using -f ), the default is to overwrite files
- Says it's not OK to overwrite files. This is useful in non-interactive
mode, so that existing files are untouched. This has lesser precedence
- Autoclear. Remove all input files that were successfully decoded. Use with
care! UUDeview only checks if any data was decoded from an input file, but
does not care about any other contents of that input file, or whether a
file also held an incomplete attachment.
- -p path
- Sets the path where decoded files shall be written to. This must be a
valid pathname, or you'll get errors when trying to decode anything.
Defaults to the current working directory.
- Ignore file mode. Uuencoded and xxencoded files have the original file
permissions stored on the begin line. Unless this option is given,
UUDeview will restore them without checking if they are sensible.
With this option, the permissions are reset to a default of 0666.
- Enforces stricter MIME adherance. Normally, the program tries to find
encoded data even in "text/plain" plaintext parts of MIME
messages. With this option given, UUDeview will limit this
capability, and will not accept apparently incomplete encoded messages
(for example, seemingly uuencoded data without begin or end lines). You
can tighten this option even more by using it twice, or by using
-z2. Then, UUDeview will not check plaintext sections of
MIME messages for encoded data at all and behave fully MIME-compliant.
Neither option affects the behavior on non-MIME input files. This option
needs a better name, but I'm slowly running out of option letters.
- Uses fast mode for file scanning. The program assumes that each input file
holds at most one part, which is usually true for files in a news spool
directory. This option breaks decoding of input files with multiple
articles. Also, certain sanity checks are disabled, probably causing
erroneous files to be presented for decoding. Sometimes you'll get error
messages when decoding, sometimes you'll just receive invalid files. Don't
use -f if you can't live with these problems.
- Ignore reply messages, i.e. all messages whose subject starts with
- Use plaintext messages. Usually, UUDeview only presents encoded data for
decoding. Plaintext messages are only shown if they have an associated
file name. With this option set, unnamed text parts from MIME
messages and non-encoded messages are also offered. Unnamed messages are
assigned a unique name in the form of a sequential four-digit number.
- Sets the program into desperate mode. It will then offer you to decode
incomplete files. This is useful if you are missing the last part of a
50-parts posting, but in most cases the desperately-decoded files will
simply be corrupt and unusable. The degree of usefulness of an incomplete
file depends on the file type.
- This changes UUDeview's "bracket policy." UUDeview
looks at a message's subject line, and reads numbers in brackets as the
part number, as in (3/7), which is read as the third message in a series
of seven. By default, numbers in parentheses () are preferred over numbers
in brackets . You can change this using either -b or, for clarity
- Read "minus smartness". This option turns off automatic part
number detection from the subject line. Try this option if UUDeview
fails to parse the subject line correctly and makes errors at guessing
part numbers, resulting in incorrect ordering of the parts. With this
option, parts are always put together sequentially (so the parts must be
correctly ordered in the input file). Also, with this option, the program
cannot detect that parts are missing. Note: The correct part number
found in proper MIME files is still evaluated. If this option is
given twice, the subject itself is ignored, too, and won't be used to
group parts. Use if the messages that the parts come delivered in have
different subject lines.
- (Quiet) Disables verbosity. Normally, the program prints some status
messages while reading the input files, which can be very helpful if
something should go wrong. Use if these messages disturb you.
- No progress bars. Normally, UUDeview prints ASCII bars crawling up to 100
percent, but does not check if your terminal is capable of displaying
them. Use this switch if your terminal isn't, or if you find the bars
- +e exts
- Selects only the files with the given extensions for decoding, others will
be ignored. +e .gif.jpg would decode all gif and jpeg files,
but not tif or other files. The list of extensions works
- -e exts
- The reverse of the above.
You will experience unwanted results if you try to mix +e and -e options on the
- The files to be scanned for encoded files. You can also give a single
hyphen ´-´ to read from standard input. Any number of files
may be given, but there is usually a limitation of 128 options imposed by
the shell. If you are composing the list of files with wildcards, make
sure you don't accidentally feed the program with binary files. This will
result in undefined behaviour.
- Makes UUDeview read further options from the file. Each line of the
file must hold exactly one option. The file is erased after the
program finishes. This feature may be used to specify an unlimited number
of files to be scanned. Combined with the powers of find(1), entire
directory trees (like the news spool directory) can be processed.
Options may also be set in the $UUDEVIEW environment variable, which is read
before processing the options on the command line.
After all input files have been scanned, you are asked for each file what do do
with it. Of course, the usual answer is to decode it, but there are other
possibilities. You can use the following commands (each command is a single
- (D)ecode the file and write the decoded file to disk, with the given
- (Y)es does the same as (d).
- E(x)tract also decodes the file.
- Decodes all remaining files without prompting.
- Skips this file without decoding it.
- Steps back to the previous file.
- Rename. You can choose a different name for the file in order to save it
under this new name.
- Set the path where decoded files shall be written to. This path can also
be set with the -p command line option.
- Displays info about the file, if present. If a multipart posting had a
zeroeth part, it is printed, otherwise the first part up to the encoded
data is printed.
- Execute a command. You can enter any arbitrary command, possibly using the
current file as an argument. All dollar signs '$' in this command line are
replaced with the filename of the current file (speaking correctly, the
name of a temporary file). You should not background processes using this
temporary file, as programs might get confused if their input file
- List a file. Use this command only if you know that the file in question
is a textfile, otherwise, you'll get a load of junk.
- Quits the program immediately.
- Prints a short description of all these commands.
If you don't enter a command and simply hit return at the prompt, the default
command, decoding the file, is used.
In verbose mode (that is, if you didn't disable verbosity with the -v option),
progress messages will appear. They are extremely helpful in tracing what the
program does, and can be used to figure out the reason why files cannot be
decoded, if you understand them. This section explains how to interpret them.
Understanding this section is not essential to operate the program.
First, there are "Loading" messages, which begin with the string
"Loaded". Each line should feature the following items:
- Source File
- The first item is the source file from which a part was loaded. Many parts
can be detected within a single file.
- Subject Line
- The complete subject is reproduced in single quotes.
- The program derives a unique identification for this thread from the
subject line, for grouping articles that look like they belong to the same
file. The result of this algorithm is presented in braces.
- If a filename was detected on the subject line or within the data (for
example, on a begin line, or as part of the Content-Type
- Part Number
- The part number derived from the subject line, or, in the case of properly
MIME-formatted messages, from the "part" information.
- If a "begin" or "end" token was detected, it is
- Encoding Type
- If encoded data was detected within this part, either "UUdata",
"Base64", "XXdata" or "Binhex" is printed
More messages are printed after scanning has completed. A single line will be
printed for each group of articles. The contents of this line are best
understood by looking at an example. Here is one:
Found 'mailfile.gz' State 16 UUData Parts begin 1 2 3 4 5 end 6 OK
This indicates that the file mailfile.gz
has been found. The file was
uuencoded ("UUData") and consists of 6 parts. The "begin"
token was found in the first part, and the "end" token was found in
the sixth part. Because it looks like everything's there, this file is tagged
as being "OK". The State
is a set of bits, where the
following values may be or'ed:
- Missing Part
- No Begin
- No End
- No encoded data found.
- File looks Ok
- An error occured during decoding of the file.
- File was successfully decoded.
Because the program cannot receive terminal input when a file is being read from
standard input, interactivity is automatically disabled in this case.
UUDeview is aware of MIME messages, but normally ignores strict MIME compliance
in favor of finding unproperly encoded data within them, e.g. to succeed when
individual parts of a uuencoded file have been sent with a MIME mailer as MIME
messages. For that, it subjects all "text/plain" parts of a message
to encoding detection. You can use the -z
option (see above) for more
strict RFC2045 compliance.
The scanner tends to ignore short Base64 data (less than four lines) outside of
MIME messages. Some checks for this condition are used in desperate mode, but
they may cause misdetection of encoded data, resulting in some invalid files.
Files are always decoded into a temporary file first, then this file is copied
to the final location. This is to prevent accidentally overwriting existing
files with data that turns out too late to be undecodeable. Thus be careful to
have twice the necessary space available. Also, when reading from standard
input, all the data is dumped to a temporary file before starting the usual
scanning process on that file.
tries to derive all necessary information from the Subject: line
if present. If it holds garbage, or if the program fails to find a unique
identification and the part number there, uudeview
might still be able
to decode the file using other heuristics, but you'll need major luck then.
Yet this is only a concern with split-files. If all encoded files only consist
of single parts, don't worry.
If you rename, copy or link the program to uudecode
, it may act as a
smart replacement for the standard, accepting the same command-line options.
This has not been well-tested yet.
homepage on the Web,
To read a file whose name starts with a hyphen '-', prepend a path name, for
The checksums found in BinHex
data are ignored.
The program cannot fully handle partial multipart messages (MIME-style multipart
messages split over several mail messages). The individual parts are
recognized and concatenated, and the embedded multipart message is
"decoded" into a plain-text file, which must then be fed again to
Don't worry, these kinds of messages are rare.
UUDeview cannot decipher RFC 1522 headers.