Provided by: mmh_0.3-3_amd64 bug

NAME

       mh-sequence - sequence specification for mh message system

DESCRIPTION

       A  sequence  (or  sequence set) is a symbolic name representing a message or collection of
       messages.  mmh has several internally defined sequences, as  well  as  allowing  users  to
       define their own sequences.

   Message Specification and Pre-Defined Message Sequences
       Most  mmh  commands  accept  a  `msg'  or  `msgs' specification, where `msg' indicates one
       message and `msgs' indicates one or more messages.  To designate a message,  you  may  use
       either its number (e.g., 1, 10, 234) or one of these `reserved' message names:

            Name      Description
            f         the first message in the folder
            p         the message numerically preceding `c'
            c         the most recently accessed message
            n         the message numerically following `c'
            l         the last message in the folder

       In commands that take a `msg' argument, the default is `c'.

       For  example: In a folder containing five messages numbered 5, 10, 94, 177 and 325, `f' is
       5 and `l' is 325.  If `c' is 94, then `p' is 10 and `n' is 177.

       The  word  `msgs'  indicates  that  one  or  more  messages  may  be  specified.   Such  a
       specification  consists  of  one  message  designation  or of several message designations
       separated by spaces.  A message designation consists either of a message name  as  defined
       above, or a message range.

       A  message  range  is  specified  as  `name1-name2' or `name:i', where `name', `name1' and
       `name2' are message names, and `i' is an integer.

       The specification `name1-name2' designates all currently existing messages from `name1' to
       `name2'  inclusive.   The  `reserved'  message  name  `a' (``all'') is a shorthand for the
       message range `f-l'.

            Name      Description
            a         all messages in the folder (i.e. `f-l')

       The specification `name:i' designates up to  `i'  messages.   These  messages  start  with
       `name'  if  `name'  is  a message number or one of the reserved names `f' `c', or `n', The
       messages end with `name' if `name' is `p' or  `l'.   The  interpretation  of  `i'  may  be
       overridden  by  preceding  `i'  with  a  plus  or  minus sign; `+i' always means up to `i'
       messages starting with `name', and `-i' always  means  up  to  `i'  messages  ending  with
       `name'.

       In commands which accept a `msgs' argument, the default is either `c' or `a', depending on
       which makes more sense for each command (see the individual man pages for details).

       Repeated specifications of the same message have the same effect as a single specification
       of the message.

       There  is  also  a special `reserved' message name `b' (``beyond'') which can be used with
       the mhpath command. It refers to the next (not yet used) message number after `l'.

            Name      Description
            b         the next message number beyond `l'

   User-Defined Message Sequences
       In addition to the `reserved' (pre-defined) message names given above, mmh supports  user-
       defined  sequence names.  User-defined sequences allow the mmh user a tremendous amount of
       power in dealing with groups of messages in the same folder by allowing the user to bind a
       group of messages to a meaningful symbolic name.

       The  name  used  to  denote  a  message  sequence  must consist of an alphabetic character
       followed by zero or more alphanumeric characters, and can not be  one  of  the  `reserved'
       message  names  above.   After defining a sequence, it can be used wherever an mmh command
       expects a `msg' or `msgs' argument.

       Some forms of message ranges are allowed with user-defined sequences.   The  specification
       `name:i' may be used, and it designates up to the first `i' messages (or last `i' messages
       for `-i') which are elements of the user-defined sequence `name'.

       The specifications `name:n' and `name:p' may also be used, and they designate the next  or
       previous message (relative to the current message) which is an element of the user-defined
       sequence `name'.  The specifications `name:f' and `name:l' are equivalent to `name:1'  and
       `name:-1',  respectively.   The  specification  `name:c'  is  not  allowed  (use  just `c'
       instead).  Note: The syntax of these message range specifications is subject to change  in
       the future.

       User-defined  sequence names are specific to each folder.  They are defined using the pick
       and mark commands.

   Public and Private User-Defined Sequences
       There are two varieties of user-defined sequences: public and private.   Public  sequences
       of  a  folder  are accessible to any mmh user that can read that folder.  They are kept in
       each folder in the file  determined  by  the  `Mh-Sequences'  profile  entry  (default  is
       .mh_sequences).   Private sequences are accessible only to the mmh user that defined those
       sequences and are kept in the user's mh context file.

       In general, the commands that create sequences (such as pick and mark) will create  public
       sequences  if  the folder for which the sequences are being defined is writable by the mmh
       user.  For most commands, this can  be  overridden  by  using  the  switches  -public  and
       -private.   But  if  the  folder  is  read-only, or if the `Mh-Sequences' profile entry is
       defined but empty, then private sequences will be created instead.

   Sequence Negation
       Mmh provides the ability to select all messages not elements of a  user-defined  sequence.
       A  special  string  is  used  to  preface  an  existing  user-defined sequence name.  This
       specification then refers to those messages not elements of the specified  sequence  name.
       The  default  negation  prefix  is  the  exlamation  mark `!', but it may be change to any
       string, by defining the entry `Sequence-Negation' in the mmh profile file.   For  example,
       if the profile entry is:

            Sequence-Negation: not

       then  anytime  an  mmh  command  is given `notfoo' as a `msg' or `msgs' argument, it would
       substitute all messages that are not elements of the sequence `foo'.

       Obviously, the user should beware of defining sequences with names  that  begin  with  the
       value  of  the `Sequence-Negation' profile entry.  The default value `!' was chosen due to
       its similar meaning in the C programming language, and because it  cannot  be  part  of  a
       user-defined  sequence.  But  if  your shell provides history expansion, you might need to
       quote the exlamation mark (prefix it with a backslash).

       To deactivate the negation mechanism, define Sequence-Negation in your profile to an empty
       value.

   The Previous Sequence
       Mmh  provides  the  ability  to remember the `msgs' or `msg' argument last given to an mmh
       command.  The entry `Previous-Sequence' should be defined in the mmh  profile;  its  value
       should  be  a sequence name or multiple sequence names separated by spaces.  If this entry
       is defined, when an mmh command finishes, it will define  the  sequence(s)  named  in  the
       value  of  this  entry  to be those messages that were specified to the command.  Hence, a
       profile entry of

            Previous-Sequence: pseq

       directs any mmh command that accepts a `msg' or `msgs' argument  to  define  the  sequence
       `pseq' as those messages when it finishes.

       Note: there can be a performance penalty in using the `Previous-Sequence' facility.  If it
       is used, all mmh programs have to write the sequence information to the .mh_sequences file
       for  the  folder  each  time  they  run.   If the `Previous-Sequence' profile entry is not
       included, only pick and mark will write to the .mh_sequences file.

   The Unseen Sequence
       Finally, the unseen sequence indicates which messages have not been previously seen by the
       user.   The  commands  inc,  rcvstore,  show,  and flist honor the sequence.  Whenever new
       messages are placed in a folder (using inc or rcvstore), the new  messages  will  also  be
       added to the unseen sequence.

       inc,  for  example,  adds new messages to the unseen sequence.  Unlike the behavior of the
       previous sequence, however, the unseen sequence will not be zeroed by inc.

       Similarly, whenever show, next, or prev display a message, that message  will  be  removed
       from the unseen sequence.

       The  default unseen sequence is named `u'.  To change, define a `Unseen-Sequence' entry in
       your profile.  It may also contain multiple sequence names, separated by spaces.  In  this
       case, anything that applied to a single unseen sequence, applies to multiple ones, too.

       The  unseen  sequence  mechanism is automatically activated.  To deactivate it, define the
       `Unseen-Sequence' entry in your profile with an empty value.

FILES

       $HOME/.mmh/profile         The user profile
       $HOME/.mmh/context         The user context
       <folder>/.mh_sequences     File for public sequences

PROFILE COMPONENTS

       Mh-Sequences:        Name of file to store public sequences
       Sequence-Negation:   To designate messages not in a sequence
       Previous-Sequence:   The last message specification given
       Unseen-Sequence:     Those messages not yet seen by the user

SEE ALSO

       flist(1), mark(1), pick(1), mh-profile(5)

DEFAULTS

       None