versions are just aliases that default to the view, edit, compose, and
print actions (respectively).
(or any of its aliases) will use the given action to process each
mime-type/file in turn. Each file is specified as its mime-type,
its encoding (e.g. compression), and filename together, separated by
colons. If the mime-type is omitted, an attempt to determine the type
is made by trying to match the file's extension with those in the
files. If the encoding is omitted, it will also be determined from
the file's extensions. Currently supported encodings are
(.Z). A filename of "-" can be used to mean "standard input", but
then a mime-type
Both the user's files (~/.mailcap; ~/.mime.types) and the system files
(/etc/mailcap; /etc/mime.types) are searched in turn for information.
extract-mail-attachment msg.txt | see image/tiff:gzip:-
All options are in the form --<opt>=<value>.
Performs the specified action on the files. Valid actions are
(uses only "copiousoutput" rules and sends output to STDOUT) ,
If no action is specified, the action will be determined by how the
program was called.
Turns on extra information to find out what is happening.
Ignores any "copiousoutput" directive and sends output to STDOUT.
Displays the found command without actually executing it.