mh-sequence - sequence specification for mh message system
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.
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:
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'.
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'.
b the next message number beyond `l'
In addition to the `reserved' (pre-defined) message names given above,
supports user-defined sequence names. User-defined sequences allow
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
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
sequences are accessible only to the mmh
user that defined those
sequences and are kept in the user's mh
In general, the commands that create sequences (such as pick
) 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
. But if the folder is read-only, or if the `Mh-Sequences'
profile entry is defined but empty, then private
sequences will be
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:
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
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.
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
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
directs any mmh
command that accepts a `msg' or `msgs' argument to define
the sequence `pseq' as those messages when it finishes.
: 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
will write to the .mh_sequences
Finally, the unseen sequence indicates which messages have not been previously
seen by the user. The commands inc
honor the sequence. Whenever new messages are placed in a folder
), the new messages will also be added to
the unseen sequence.
, for example, adds new messages to the unseen sequence. Unlike the
behavior of the previous sequence, however, the unseen sequence will
be zeroed by inc
Similarly, whenever show
, 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.
^$HOME/.mmh/profile~^The user profile
^$HOME/.mmh/context~^The user context
^<folder>/.mh_sequences~^File for public sequences
^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
flist(1), mark(1), pick(1), mh-profile(5)