mhn.man

早期freebsd实现

MHN(1)                 BSD Reference Manual                MHN(1)


       Example entries might be:

            mhn-store-text: %m%P.txt
            mhn-store-audio/basic: | raw2audio -e ulaw -s 8000 -c 1 > %m%P.au
            mhn-store-application/PostScript: %m%P.ps

       Further,  note that when asked to store a content contain-
       ing a partial message, _m_h_n will try to locate all  of  the
       portions and combine them accordingly.  Thus, if someone's
       sent you a message in several parts, you  might  put  them
       all in their own folder and do:

            mhn all -store

       This will store exactly one message, containing the sum of
       the parts.  Note that if _m_h_n can not locate each part,  it
       will not store anything.

       Finally,  if  the  `-auto' switch is given and the content
       contains information indicating the filename  the  content
       should  be  stored  as  (and if the filename doesn't begin
       with a '/'), then the filename from the  content  will  be
       used instead.


   EExxtteerrnnaall AAcccceessss
       For  contents  of type message/external-body, _m_h_n supports
       these access-types:

            afs
            anon-ftp
            ftp
            local-file
            mail-server

       For the "anon-ftp" and "ftp" access types, if your  system
       supports  a SOCKETs interface to TCP/IP, then _m_h_n will use
       a built-in FTP client.  Otherwise, _m_h_n will look  for  the
       mmhhnn--aacccceessss--ffttpp profile entry, e.g.,

            mhn-access-ftp: myftp.sh

       to  determine the pathname of a program to perform the FTP











[mh.6]                        MH.6.8                            7








MHN(1)                 BSD Reference Manual                MHN(1)


       retrieval.  This program is invoked with these arguments:

            domain name of FTP-site
            username
            password
            remote directory
            remote filename
            local filename
            "ascii" or "binary"

       The program should  terminate  with  a  zero-valued  exit-
       status if the retrieval is successful.


   TThhee CCoonntteenntt CCaacchhee
       When _m_h_n encounters an external content containing a "Con-
       tent-ID:" field, and if the content allows  caching,  then
       depending  on  the  caching  behavior  of _m_h_n, the content
       might be read from or written to a cache.

       The  caching  behavior  of  _m_h_n  is  controlled  with  the
       `-rcache'  and `-wcache' switches, which define the policy
       for reading from, and writing to, the cache, respectively.
       One  of four policies may be specified: "public", indicat-
       ing that _m_h_n should make use  of  a  publically-accessible
       content  cache; "private", indicating that _m_h_n should make
       use of the user's private content cache; "never", indicat-
       ing that _m_h_n should never make use of caching; and, "ask",
       indicating that _m_h_n should ask the user.

       There are two directories where contents  may  be  cached:
       the  profile  entry mmhhnn--ccaacchhee names a directory containing
       world-readable  contents,  and,  the  profile  entry  mmhhnn--
       pprriivvaattee--ccaacchhee  names  a  directory containing private con-
       tents.  The former should be an absolute  (rooted)  direc-
       tory name.  For example,

            mhn-cache: /tmp

       might  be used if you didn't care that the cache got wiped
       after each reboot of the system.   The  latter  is  inter-
       preted relative to the user's MH directory, if not rooted,
       e.g.,

            mhn-private-cache: .cache

       (which is the default value).







[mh.6]                        MH.6.8                            8








MHN(1)                 BSD Reference Manual                MHN(1)


   CCaacchhiinngg tthhee CCoonntteennttss
       When you encounter a content of type message/external-body
       with  access  type  "mail-server", _m_h_n will ask you if may
       send a message to a mail-server  requesting  the  content,
       e.g.,

            % show 1
            Retrieve content by asking mail-server@...

            SEND file

            ? yes
            mhn: request sent

       Regardless  of  your decision, _m_h_n can't perform any other
       processing on the content.

       However, if _m_h_n is allowed to request  the  content,  then
       when it arrives, there should be a top-level "Content-ID:"
       field which corresponds to the value in the original  mes-
       sage/external-body   content.   You  should  now  use  the
       `-cache' switch to tell _m_h_n to enter the arriving  content
       into the content cache, e.g.,

            % mhn -cache 2
            caching message 2 as file ...

       You can then re-process the original message/external-body
       content, and "the right thing should happen", e.g.,

            % show 1
             ...


   CCoommppoossiinngg tthhee CCoonntteennttss
       The _m_h_n program can also be used as a simple editor to aid
       in  composing  multi-media  messages.   When  invoked by a
       _w_h_a_t_n_o_w program, _m_h_n will expect the body of the draft  to
       be formatted as an "_m_h_n composition file."















[mh.6]                        MH.6.8                            9








MHN(1)                 BSD Reference Manual                MHN(1)


       The syntax of this is straight-forward:

               body         ::=     1*(content | EOL)

               content      ::=     directive | plaintext

               directive    ::=     "#" type "/" subtype
                                        0*(";" attribute "=" value)
                                        [ "(" comment ")" ]
                                        [ "<" id ">" ]
                                        [ "[" description "]" ]
                                        [ filename ]
                                        EOL

                                  | "#@" type "/" subtype
                                        0*(";" attribute "=" value)
                                        [ "(" comment ")" ]
                                        [ "<" id ">" ]
                                        [ "[" description "]" ]
                                        external-parameters
                                        EOL

                                  | "#forw"
                                        [ "<" id ">" ]
                                        [ "[" description "]" ]
                                        [ "+"folder ] [ 0*msg ]
                                        EOL

                                  | "#begin"
                                          [ "<" id ">" ]
                                          [ "[" description "]" ]
                                          [   "alternative"
                                            | "parallel"
                                            | something-else    ]
                                          EOL
                                        1*body
                                    "#end" EOL

               plaintext    ::=     [ "Content-Description:"
                                          description EOL EOL ]
                                        1*line
                                    [ "#" EOL ]

                                  | "#<" type "/" subtype
                                        0*(";" attribute "=" value)
                                        [ "(" comment ")" ]
                                        [ "[" description "]" ]
                                        EOL
                                        1*line
                                    [ "#" EOL ]




[mh.6]                        MH.6.8                           10








MHN(1)                 BSD Reference Manual                MHN(1)


               line         ::=     "##" text EOL
                                    -- interpreted as "#"text EOL
                                  | text EOL

       Basically, the body contains one or more contents.  A con-
       tent consists of either a directive, indicated with a  "#"
       as  the  first  character of a line; or, plaintext (one or
       more lines of text).  The continuation character, "\", may
       be used to enter a single directive on more than one line,
       e.g.,

            #@application/octet-stream; \
                type=tar; \
                x-conversions=compress

       There are four kinds  of  directives:  "type"  directives,
       which name the type and subtype of the content; "external-
       type" directives, which also name the type and subtype  of
       the  content;  the "forw" directive, which is used to for-
       ward a digest of messages;  and,  the  "begin"  directive,
       which is used to create a multipart content.

       For  the  type directives, the user may optionally specify
       the name of a file containing  the  contents  in  "native"
       (decoded)  format.   (If  the filename starts with the "|"
       character, then this gives a command whose output is  cap-
       tured  accordingly.)  If a filename is not given, _m_h_n will
       look for information in the user's  profile  to  determine
       how  the  different  contents should be composed.  This is
       accomplished by consulting a composition string, and  exe-
       cuting  it  under //bbiinn//sshh, with the standard output set to
       the content.  The composition  string  may  contain  these
       escapes:

            %a  additional arguments
            %f  filename containing content
            %F  %f, and stdout is not re-directed
            %s  subtype

       First, _m_h_n will look for an entry of the form:

            mhn-compose-<type>/<subtype>

       to  determine  the  command to use to compose the content.
       If this isn't found, _m_h_n will look for  an  entry  of  the
       form:

            mhn-compose-<type>

       to  determine  the  composition  command.   If  this isn't
       found, _m_h_n will complain.



[mh.6]                        MH.6.8                           11








MHN(1)                 BSD Reference Manual                MHN(1)


       An example entry might be:

            mhn-compose-audio/basic: record | raw2audio -F

       Because commands like these will vary,  depending  on  the
       display  environment  used  for login, composition strings
       for different contents should probably be put in the  file
       specified  by  the  $$MMHHNN  environment variable, instead of
       directly in your user profile.

       The external-type directives are used to provide a  refer-
       ence  to  a  content,  rather  than enclosing the contents
       itself.  Hence, instead of providing a  filename  as  with
       the  type  directives,  external-parameters  are supplied.
       These look like regular parameters, so they must be  sepa-
       rated accordingly, e.g.,

            #@application/octet-stream; \
                type=tar; \
                x-conversions=compress [] \
                access-type=anon-ftp; \
                name="mh-mime.tar.Z"; \
                directory="mrose/mh-mime"; \
                site="ftp.ics.uci.edu"

       By  specifying "[]", an empty description string is given,
       and the start of the  external-parameters  is  identified.
       These parameters are of the form:

            access-type=  usually _a_n_o_n_-_f_t_p or _m_a_i_l_-_s_e_r_v_e_r
            name=         filename
            permission=   read-only or read-write
            site=         hostname
            directory=    directoryname (optional)
            mode=         usually _a_s_c_i_i or _i_m_a_g_e (optional)
            size=         number of octets
            server=       mailbox
            subject=      subject to send
            body=         command to send for retrieval


       For  the  forw  directive, the user may optionally specify
       the name of the folder and which messages are to  be  for-
       warded.  if a folder is not given, it defaults to the cur-
       rent folder.  Similarly, if a message  is  not  given,  it
       defaults  to  the current message.  Hence, the forw direc-
       tive is similar to the _f_o_r_w (1) command, except  that  the
       former  uses  the MIME rules for encapsulation rather than
       those specified in RFC 934.  Usage  of  the  `-rfc934mode'
       switch indicates whether _m_h_n should attempt to utilize the
       encapsulation rules in such a way as to  appear  that  RFC



[mh.6]                        MH.6.8                           12