ulti-purpose Internet Mail Extensions allow the transmission of files, images,
and other formats using standard internet mail. This frees users from having
to encode all their non-textual information into seven-bit ASCII. (When
files are "attached" to mail, this is the method that is used.)
One nice feature of Netscape 2.0 is automatic decoding. If you attach an
HTML document, graphic file, etc. to mail or news it is automatically
displayed below the body of the message. Pine allows you to save attached
messages easily, while elm takes a little more coercion.
UUencoding is the conversion of binary data (typically picture, sound, and
files) into seven-bit ASCII for transmission within normal electronic mail
A typical encoding command is
uuencode file1 file2 >>
will extract the information. A somewhat more robust decoder is
The UNIX Tape Archive format is used to combine multiple files in many
directories into one large convenient file for electronic transfer. Since
it was not originally designed for hard disk systems, there are some options
that are always necessary:
tar xvf file.tar to detar a file (x for extract, v for
verbose, f for file). Likewise,
tar cf tarfile.tar directory
will put all the files in a particular directory into
Like its PC counterpart PKZIP, Gzip quickly archives and compresses files
for transfer. Other formats besides the popular .gz and .Z of Gzip and
PKZIP are ARC,LHZ and ZOO.
A PC favorite, PKZIP and its related
programs allow fast, easy compression
and archival of files. Another useful application is
a powerful Windows-based decompression tool that supports many formats. It
also has many useful options, such
as "tryout" which allows you to undo changes to the Windows .ini files. The
new version for Windows 95 also supports long filenames and works integrally
with Microsoft Explorer.
Graphics and Video
Most compression schemes for graphics and video are "lossy", which means that
some information is lost during encoding. In order to view XBM, GIF, JPG
and the multitude of other graphics formats, a good viewer such as
needed. XANIM is a
movie player that supports many different movie formats as well as sound.
Both it and XV are in
/usr/cs/contrib/bin as "xanim" and "xv.310" respectively.