SCAN(1) [nmh-1.0.4] (MH.6.8) SCAN(1)
NAME
scan - produce a one line per message scan listing
SYNOPSIS
scan [+folder] [msgs] [-clear] [-noclear] [-form formatfile]
[-format string] [-header] [-noheader] [-width columns]
[-reverse] [-noreverse] [-file filename]
[-version] [-help]
DESCRIPTION
Scan produces a one-line-per-message listing of the
specified folder or messages. Each scan line contains the
message number (name), the date, the From: field, the
Subject field, and, if room allows, some of the body of the
message. For example:
15+ 10/05 crocker nned Last week I asked some of
16- 10/05 crocker message id format I recommend
18 10/06 brien Re: Exit status from mkdir
19 10/07*brien scan listing format in nmh
The `+' on message 15 indicates that it is the current
message.
The `-' on message 16 indicates that it has been replied to,
as indicated by a Replied: component (produced by the
`-annotate' switch to the repl command).
The `*' on message 19 indicates that no Date: header was
present. The time of last modification of the message is
given instead.
If there is sufficient room left on the scan line after the
subject, the line will be filled with text from the body,
preceded by <<, and terminated by >> if the body is
sufficiently short. Scan actually reads each of the
specified messages and parses them to extract the desired
fields. During parsing, appropriate error messages will be
produced if there are format errors in any of the messages.
By default, scan will decode RFC-2047 (MIME) encoding in
these scan listings. Scan will only decode these fields if
your terminal can natively display the character set used in
the encoding. You should set the MM_CHARSET environment
variable to your native character set, if it is not US-
ASCII. See the mh-profile(5) man page for details about
this environment variable.
The switch `-reverse', makes scan list the messages in
reverse order.
The `-file filename' switch allows the user to obtain a scan
Page 1 (printed 2/1/01)
SCAN(1) [nmh-1.0.4] (MH.6.8) SCAN(1)
listing of a maildrop file as produced by packf. This
listing includes every message in the file (you can't scan
individual messages). The switch `-reverse' is ignored with
this option.
The switch `-width columns' may be used to specify the width
of the scan line. The default is to use the width of the
terminal.
The `-header' switch produces a header line prior to the
scan listing. Currently, the name of the folder and the
current date and time are output (see the HISTORY section
for more information).
If the `-clear' switch is used and scan's output is directed
to a terminal, then scan will consult the environment
variables $TERM and $TERMCAP to determine your terminal type
in order to find out how to clear the screen prior to
exiting. If the `-clear' switch is used and scan's output
is not directed to a terminal (e.g., a pipe or a file), then
scan will send a formfeed prior to exiting.
For example, the command:
(scan -clear -header; show all -show pr -f) | lpr
produces a scan listing of the current folder, followed by a
formfeed, followed by a formatted listing of all messages in
the folder, one per page. Omitting `-show pr -f' will cause
the messages to be concatenated, separated by a one-line
header and two blank lines.
To override the output format used by scan, the
`-format string' or `-form file' switches are used. This
permits individual fields of the scan listing to be
extracted with ease. The string is simply a format string
and the file is simply a format file. See mh-format(5) for
the details.
In addition to the standard mh-format(5) escapes, scan also
recognizes the following additional component escapes:
Escape Returns Description
body string the (compressed) first part of the body
dtimenow date the current date
folder string the name of the current folder
If no date header is present in the message, the function
escapes which operate on {date} will return values for the
date of last modification of the message file itself. This
feature is handy for scanning a draft folder, as message
drafts usually aren't allowed to have dates in them.
Page 2 (printed 2/1/01)
SCAN(1) [nmh-1.0.4] (MH.6.8) SCAN(1)scan will update the nmh context prior to starting the
listing, so interrupting a long scan listing preserves the
new context. nmh purists hate this idea.
FILES
$HOME/.mh_profile The user profile
PROFILE COMPONENTS
Path: To determine the user's nmh directory
Alternate-Mailboxes: To determine the user's mailboxes
Current-Folder: To find the default current folder
SEE ALSO
inc(1), pick(1), show(1), mh-format(5)
DEFAULTS
`+folder' defaults to the current folder
`msgs' defaults to all
`-format' defaulted as described above
`-noheader'
`-width' defaulted to the width of the terminal
CONTEXT
If a folder is given, it will become the current folder.
HISTORY
Prior to using the format string mechanism, `-header' used
to generate a heading saying what each column in the listing
was. Format strings prevent this from happening.
BUGS
The argument to the `-format' switch must be interpreted as
a single token by the shell that invokes scan. Therefore,
one must usually place the argument to this switch inside
double-quotes.
The value of each component escape is set by scan to the
contents of the first message header scan encounters with
the corresponding component name; any following headers with
the same component name are ignored.
Page 3 (printed 2/1/01)
