SCAN(1) 							     [nmh-1.5]								   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 | -nore-
	    verse] [-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 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 $TERM-
       CAP 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 modifica-
       tion 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.

       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 quotes.

       The value of each component escape is set by scan to the contents of the first message header scan encounters with the corresponding compo-
       nent name; any following headers with the same component name are ignored.

MH.6.8								   11 June 2012 							   SCAN(1)