.\"
.TH MH-SEQUENCE %manext7% "%nmhdate%" MH.6.8 [%nmhversion%]
.SH NAME
-mh-sequence \- sequence specification for nmh message system
+mh-sequence \- sequence specification for mh message system
.SH DESCRIPTION
A sequence (or sequence set) is a symbolic name representing a
message or collection of messages.
-.B nmh
+.B mmh
has several internally
defined sequences, as well as allowing users to define their own
sequences.
.SS "Message Specification and Pre\-Defined Message Sequences"
Most
-.B nmh
+.B 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)
.SS "User\-Defined Message Sequences"
In addition to the `reserved' (pre-defined) message names given
above,
-.B nmh
+.B mmh
supports user-defined sequence names. User-defined
sequences allow the
-.B nmh
+.B 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.
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
-.B nmh
+.B mmh
command expects a `msg' or
`msgs' argument.
.PP
.SS "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
-.B nmh
+.B 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
.IR \&.mh_sequences ).
Private sequences are accessible
only to the
-.B nmh
+.B mmh
user that defined those sequences and are kept in
the user's
-.B nmh
+.B mh
context file.
.PP
In general, the commands that create sequences (such as
.BR mark )
will create public sequences if the folder for which
the sequences are being defined is writable by the
-.B nmh
+.B mmh
user.
For most commands, this can be overridden by using the switches
.B \-public
\fIprivate\fR sequences will be created instead.
.SS "Sequence Negation"
-.B Nmh
+.B Mmh
provides the ability to select all messages
.B not
elements of a user-defined sequence.
The default negation prefix is the exlamation mark `!',
but it may be change to any string, by defining the entry
`Sequence\-Negation' in the
-.B nmh
+.B mmh
profile file.
For example, if the profile entry is:
.PP
.RE
.PP
then anytime an
-.B nmh
+.B mmh
command is given `notfoo' as a `msg' or
`msgs' argument, it would substitute all messages that are not elements
of the sequence `foo'.
To deactivate the negation mechanism, define Sequence\-Negation in your
profile to an empty value.
-.SS "The Previous Sequence"
-.B Nmh
-provides the ability to remember the `msgs' or `msg' argument
-last given to an
-.B nmh
-command. The entry `Previous\-Sequence'
-should be defined in the
-.B nmh
-profile; its value should be a sequence
-name or multiple sequence names separated by spaces. If this entry
-is defined, when an
-.B nmh
-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
-.PP
-.RS 5
-Previous\-Sequence: pseq
-.RE
-.PP
-directs any
-.B nmh
-command that accepts a `msg' or `msgs' argument to
-define the sequence `pseq' as those messages when it finishes.
-.PP
-.BR Note :
-there can be a performance penalty in using the
-`Previous\-Sequence' facility. If it is used,
-.B all
-.B nmh
-programs have to write the sequence information to the
-.I \&.mh_sequences
-file for the folder each time they run. If the
-`Previous\-Sequence' profile entry is not included, only
-.B pick
-and
-.B mark
-will write to the
-.B \&.mh_sequences
-file.
-
.SS "The Unseen Sequence"
Finally, the unseen sequence indicates which messages have not been
previously seen by the user.
.BR inc ,
for example,
adds new messages to the unseen sequence.
-Unlike the behavior of the previous sequence, however,
-the unseen sequence will
+The unseen sequence will
.B not
be zeroed by
.BR inc .
.PP
-Similarly, whenever
+Whenever
.BR show ,
.BR next ,
or
.ta \w'ExtraBigProfileName 'u
^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
.fi
.SH "SEE ALSO"
flist(1), mark(1), pick(1), mh-profile(5)
+.SH "HISTORY"
+.SS Previous\-Sequence
+This sequence stored the selected messages for the previous
+.B mmh
+command.
+It was disabled by default because it introduced a lot of extra writes to the
+.IR \&.mh_sequences
+file.
+Additionally, it introduced possible race conditions when running multiple
+.B mmh
+commands in parallel.
+As this feature was rarely used, it was removed.
+
.SH DEFAULTS
None
projects / mmh / blobdiff