scan

SCAN(1mh)                                                              SCAN(1mh)



NAME
       scan - produce a summary listing of nmh messages

SYNOPSIS
       scan [-help] [-version] [+folder] [msgs] [-clear | -noclear] [-form
            formatfile] [-format string] [-header | -noheader] [-width columns]
            [-reverse | -noreverse] [-file filename]

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 appropriate locale(1) environment variables to your native character
       set, if it is not US-ASCII.  See locale(1) for more details on the
       appropriate environment variables.

       The switch -reverse, makes scan list the messages in reverse order.

       The -file filename switch allows the user to obtain a scan listing of a
       mail drop 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

       {body} returns a string without MIME decoding, i.e. the MIME boundary
       seperator may be the first text shown.

       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.

       The /etc/nmh directory contains several format files as examples of
       customized scan output.

       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
       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 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.



nmh-1.7.1                          2014-01-20                          SCAN(1mh)