PICK(1) [mh.6] PICK(1)
NAME
pick - select messages by content
SYNOPSIS
pick [+folder] [msgs] [-and ...] [-or ...] [-not ...]
[-lbrace ... -rbrace] [--component pattern]
[-after date] [-before date] [-datefield field]
[-sequence name ...] [-public] [-nopublic] [-zero]
[-nozero] [-list] [-nolist] [-help]
typically:
scan `pick -from jones`
pick -to holloway -sequence select
show `pick -before friday`
DESCRIPTION
Pick searches messages within a folder for the specified
contents, and then identifies those messages. Two types
of search primitives are available: pattern matching and
date constraint operations.
A modified grep(1) is used to perform the matching, so the
full regular expression (see ed(1)) facility is available
within `pattern'. With `-search', `pattern' is used
directly, and with the others, the grep pattern con-
structed is:
component[ \t]*:.*pattern
This means that the pattern specified for a `-search' will
be found everywhere in the message, including the header
and the body, while the other pattern matching requests
are limited to the single specified component. The
expression
`--component pattern'
is a shorthand for specifying
`-search component[ \t]*:.*pattern '
It is used to pick a component which is not one of To:,
cc:, Date:, From:, or Subject:. An example is
`pick --reply-to pooh'.
Pattern matching is performed on a per-line basis. Within
the header of the message, each component is treated as
one long line, but in the body, each line is separate.
Lower-case letters in the search pattern will match either
lower or upper case in the message, while upper case will
match only upper case.
Independent of any pattern matching operations requested,
the switches `-after date' or `-before date' may also be
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PICK(1) [mh.6] PICK(1)
used to introduce date/time contraints on all of the mes-
sages. By default, the Date: field is consulted, but if
another date yielding field (such as BB-Posted: or Deliv-
ery-Date:) should be used, the `-datefield field' switch
may be used. Pick will actually parse the date fields in
each of the messages specified in `msgs' (unlike the
`-date' switch described above which does a pattern match-
ing operation), and compare them to the date/time speci-
fied by use of the `-after' and `-before' switches. If
`-after' is given, then only those messages whose Date:
field value is chronologically after the date specified
will be considered. The `-before' switch specifies the
complimentary action.
Both the `-after' and `-before' switches take legal
822-style date specifications as arguments. Pick will
default certain missing fields so that the entire date
need not be specified. These fields are (in order of
defaulting): timezone, time and timezone, date, date and
timezone. All defaults are taken from the current date,
time, and timezone. In addition to 822-style dates, pick
will also recognize any of the days of the week (sunday,
monday, and so on), and the special dates today, yester-
day, and tomorrow. All days of the week are judged to
refer to a day in the past (e.g., telling pick saturday on
a tuesday means last saturday not this saturday).
Finally, in addition to these special specifications, pick
will also honor a specification of the form -dd, which
means dd days ago.
Pick supports complex boolean operations on the searching
primitives with the `-and', `-or', `-not', and
`-lbrace ... -rbrace' switches. For example,
pick -after yesterday -and -lbrace -from freida -or -from fear -rbrace
identifies messages recently sent by frieda or fear.
The matching primitives take precedence over the `-not'
switch, which in turn takes precedence over `-and' which
in turn takes precedence over `-or'. To override the
default precedence, the `-lbrace' and `-rbrace' switches
are provided, which act just like opening and closing
parentheses in logical expressions.
Once the search has been performed, if the `-list' switch
is given, the message numbers of the selected messages are
written to the standard output separated by newlines.
This is extremely useful for quickly generating arguments
for other MH programs by using the backquoting syntax of
the shell. For example, the command
scan `pick +todo -after 31 Mar 83 0123 PST`
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PICK(1) [mh.6] PICK(1)
says to scan those messages in the indicated folder which
meet the appropriate criterion. Note that since pick 's
context changes are written out prior to scan 's invoca-
tion, you need not give the folder argument to scan as
well.
Regardless of the operation of the `-list' switch, the
`-sequence name' switch may be given once for each
sequence the user wishes to define. For each sequence
named, that sequence will be defined to mean exactly those
messages selected by pick. For example,
pick -from frated -seq fred
defines a new message sequence for the current folder
called fred which contains exactly those messages that
were selected.
Note that whenever pick processes a `-sequence name'
switch, it sets `-nolist'.
By default, pick will zero the sequence before adding it.
This action can be disabled with the `-nozero' switch,
which means that the messages selected by pick will be
added to the sequence, if it already exists, and any mes-
sages already a part of that sequence will remain so.
The `-public' and `-nopublic' switches are used by pick in
the same way mark uses them.
FILES
$HOME/.mh_profile The user profile
PROFILE COMPONENTS
Path: To determine the user's MH directory
Current-Folder: To find the default current folder
SEE ALSO
mark(1)
DEFAULTS
`+folder' defaults to the current folder
`msgs' defaults to all
`-datefield date'
`-nopublic' if the folder is read-only, `-public' otherwise
`-zero'
`-list' is the default if no `-sequence', `-nolist' otherwise
CONTEXT
If a folder is given, it will become the current folder.
HISTORY
In previous versions of MH, the pick command would show,
scan, or refile the selected messages. This was rather
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inverted logic from the UNIX point of view, so pick was
changed to define sequences and output those sequences.
Hence, pick can be used to generate the arguments for all
other MH commands, instead of giving pick endless switches
for invoking those commands itself.
Also, previous versions of pick balked if you didn't spec-
ify a search string or a date/time constraint. The cur-
rent version does not, and merely matches the messages you
specify. This lets you type something like:
show `pick last:20 -seq fear`
instead of typing
mark -add -nozero -seq fear last:20
show fear
Finally, timezones used to be ignored when comparing
dates: they aren't any more.
BUGS
The argument to the `-after' and `-before' switches must
be interpreted as a single token by the shell that invokes
pick. Therefore, one must usually place the argument to
this switch inside double-quotes. Furthermore, any occu-
rance of `-datefield' must occur prior to the `-after' or
`-before' switch it applies to.
If pick is used in a back-quoted operation, such as
scan `pick -from jones`
and pick fails (e.g., no messages are from jones), then
the shell will still run the outer command (e.g., scan).
Since no messages were matched, pick produced no output,
and the argument given to the outer command as a result of
backquoting pick is empty. In the case of MH programs,
the outer command now acts as if the default `msg' or
`msgs' should be used (e.g., all in the case of scan ).
To prevent this unexpected behavior, if `-list' was given,
and if its standard output is not a tty, then pick outputs
the illegal message number 0 when it fails. This lets the
outer command fail gracefully as well.
MH April 22, 1986 4