FORMAIL(1)		    General Commands Manual		    FORMAIL(1)



NAME
       formail - mail (re)formatter

SYNOPSIS
       formail [+skip] [-total] [-bczfrktedqBY] [-p prefix]
	    [-D maxlen idcache]
	    [-l folder]
	    [-x headerfield] [-X headerfield]
	    [-a headerfield] [-A headerfield]
	    [-i headerfield] [-I headerfield]
	    [-u headerfield] [-U headerfield]
	    [-R oldfield newfield]
	    [-n [maxprocs ]] [-m minfields] [-s [command [arg ...]]]
       formail -v

DESCRIPTION
       formail is a filter that can be used to force mail into mailbox format,
       perform `From ' escaping, generate  auto-replying  headers,  do	simple
       header  munging/extracting  or split up a mailbox/digest/articles file.
       The mail/mailbox/article contents will be expected on stdin.

       If formail is supposed to determine the sender  of  the	mail,  but  is
       unable to find any, it will substitute `foo@bar'.

       If  formail  is started without any command line options, it will force
       any mail coming from stdin into mailbox	format	and  will  escape  all
       bogus `From ' lines with a `>'.

OPTIONS
       -v   Formail will print its version number and exit.

       -b   Don't  escape any bogus mailbox headers (i.e., lines starting with
	    `From ').

       -p prefix
	    Define a different quotation prefix.  If unspecified  it  defaults
	    to `>'.

       -Y   Assume  traditional Berkeley mailbox format, ignoring any Content-
	    Length: fields.

       -c   Concatenate continued fields in the header.	 Might	be  convenient
	    when postprocessing mail with standard (line oriented) text utili-
	    ties.

       -z   Ensure a whitespace exists between field name  and	content.   Zap
	    fields  which  contain  only  a  single whitespace character.  Zap
	    leading and trailing whitespace on fields extracted with -x.

       -f   Force formail to simply pass along any non-mailbox	format	(i.e.,
	    don't generate a `From ' line as the first line).

       -r   Generate  an auto-reply header.  This will normally throw away all
	    the existing fields (except	 X-Loop:)  in  the  original  message,
	    fields  you wish to preserve need to be named using the -i option.
	    If you use this option in conjunction with -k, you can prevent the
	    body from being `escaped' by also specifying -b.

       -k   When  generating  the auto-reply header or when extracting fields,
	    keep the body as well.

       -t   Trust the sender to have  used  a  valid  return  address  in  his
	    header.   This  causes formail to select the header sender instead
	    of the envelope sender for the reply.  This option should be  used
	    when  generating auto-reply headers from news articles or when the
	    sender of the message is expecting a reply.

       -s   The input will be split up into separate mail messages, and	 piped
	    into  a  program  one  by  one (a new program is started for every
	    part).  -s has to be the last option specified, the first argument
	    following  it  is  expected to be the name of a program, any other
	    arguments will be passed along to it.  If you  omit	 the  program,
	    then  formail  will	 simply	 concatenate the split mails on stdout
	    again.  See FILENO.

       -n [maxprocs]
	    Tell formail not to wait for every program to finish before start-
	    ing	 the  next  (causes splits to be processed in parallel).  Max-
	    procs optionally specifies an upper limit on the number of concur-
	    rently running processes.

       -e   Do	not  require  empty  lines to be preceding the header of a new
	    message (i.e.,  the messages could start on every line).

       -d   Tell formail that the messages it is supposed to split need not be
	    in	strict mailbox format (i.e., allows you to split digests/arti-
	    cles or non-standard mailbox formats).  This disables  recognition
	    of the Content-Length: field.

       -l folder
	    Generate  a	 log  summary  in  the	same  style as procmail.  This
	    includes the entire "From " line, the Subject: header  field,  the
	    folder,  and  the size of the message in bytes.  The mailstat com-
	    mand can be used to summarize logs in this format.

       -B   Makes formail assume that it is splitting up a BABYL rmail file.

       -m minfields
	    Allows you to specify the number of consecutive headerfields  for-
	    mail  needs	 to find before it decides it found the start of a new
	    message, it defaults to 2.

       -q   Tells formail to (still detect but) be quiet about	write  errors,
	    duplicate  messages	 and  mismatched Content-Length: fields.  This
	    option is on by default, to make it display the messages use -q-.

       -D maxlen idcache
	    Formail will detect if the Message-ID of the current  message  has
	    already  been  seen	 using an idcache file of approximately maxlen
	    size.  If not splitting, it will return success if a duplicate has
	    been  found.  If splitting, it will not output duplicate messages.
	    If used in conjunction with -r, formail  will  look	 at  the  mail
	    address of the envelope sender instead at the Message-ID.

       -x headerfield
	    Extract  the  contents  of this headerfield from the header.  Line
	    continuations will be left intact; if you want the value on a sin-
	    gle line then you'll also need the -c option.

       -X headerfield
	    Same as -x, but also preserves/includes the field name.

       -a headerfield
	    Append a custom headerfield onto the header; but only if a similar
	    field does not exist yet.  If you specify either one of the	 field
	    names  Message-ID:	or  Resent-Message-ID: with no field contents,
	    then formail will generate a unique message-ID for you.

       -A headerfield
	    Append a custom headerfield onto the header in any case.

       -i headerfield
	    Same as -A, except that any existing similar fields are renamed by
	    prepending	an ``Old-'' prefix.  If headerfield consists only of a
	    field-name, it will not be appended.

       -I headerfield
	    Same as -i, except that any existing  similar  fields  are	simply
	    removed.   If headerfield consists only of a field-name, it effec-
	    tively deletes the field.

       -u headerfield
	    Make the first occurrence of this field unique,  and  thus	delete
	    all subsequent occurrences of it.

       -U headerfield
	    Make the last occurrence of this field unique, and thus delete all
	    preceding occurrences of it.

       -R oldfield newfield
	    Renames all occurrences of the fieldname oldfield into newfield.

       +skip
	    Skip the first skip messages while splitting.

       -total
	    Output at most total messages while splitting.

NOTES
       When renaming, removing, or extracting fields, partial  fieldnames  may
       be used to specify all fields that start with the specified value.

       By  default,  when generating an auto-reply header procmail selects the
       envelope sender from the input message.	This is correct	 for  vacation
       messages	 and other automatic replies regarding the routing or delivery
       of the original message.	 If the sender is expecting  a	reply  or  the
       reply  is  being	 generated in response to the contents of the original
       message then the -t option should be used.

       RFC822, the original standard governing the  format  of	Internet  mail
       messages,  did  not  specify  whether  Resent header fields (those that
       begin with `Resent-', such as `Resent-From:') should be considered when
       generating  a  reply.   Since then, the recommended usage of the Resent
       headers has evolved to consider them as purely  informational  and  not
       for  use	 when  generating a reply.  This has been codified in RFC2822,
       the new Internet Message Format standard, which states in part:

	      Resent fields are used to identify  a  message  as  having  been
	      reintroduced  into  the transport system by a user.  The purpose
	      of using resent fields is to have	 the  message  appear  to  the
	      final  recipient	as  if	it  were sent directly by the original
	      sender,  with  all  of  the  original   fields   remaining   the
	      same....They  MUST  NOT  be  used	 in  the  normal processing of
	      replies or other such automatic actions on messages.

       While  formail  now  ignores  Resent  headers  when  generating	header
       replies,	 versions  of  formail	prior to 3.14 gave such headers a high
       precedence.  If the old behavior is needed for established applications
       it  can be specified by calling formail with the option `-a Resent-' in
       addition to the -r and -t options.  This usage is deprecated and should
       not be used in new applications.

ENVIRONMENT
       FILENO
	    While  splitting,  formail	assigns	 the  message number currently
	    being output to this variable.   By	 presetting  FILENO,  you  can
	    change  the initial message number being used and the width of the
	    zero-padded output.	 If FILENO is unset it will  default  to  000.
	    If	FILENO is non-empty and does not contain a number, FILENO gen-
	    eration is disabled.

EXAMPLES
       To split up a digest one usually uses:
	      formail +1 -ds >>the_mailbox_of_your_choice
       or
	      formail +1 -ds procmail

       To remove all Received: fields from the header:
	      formail -I Received:

       To remove all fields except From: and Subject: from the header:
	      formail -k -X From: -X Subject:

       To supersede the Reply-To: field in a header you could use:
	      formail -i "Reply-To: foo@bar"

       To convert a non-standard mailbox file into a standard mailbox file you
       can use:
	      formail -ds <old_mailbox >>new_mailbox

       Or, if you have a very tolerant mailer:
	      formail -a Date: -ds <old_mailbox >>new_mailbox

       To extract the header from a message:
	      formail -X ""
       or
	      sed -e '/^$/ q'

       To extract the body from a message:
	      formail -I ""
       or
	      sed -e '1,/^$/ d'

SEE ALSO
       mail(1), binmail(1), sendmail(8), procmail(1), sed(1), sh(1), RFC822,
       RFC2822, RFC1123

DIAGNOSTICS
       Can't fork	      Too many processes on this machine.

       Content-Length: field exceeds actual length by nnn bytes
			      The Content-Length: field in the	header	speci-
			      fied  a  length  that was longer than the actual
			      body.  This causes this message to absorb a num-
			      ber  of  subsequent messages following it in the
			      same mailbox.

       Couldn't write to stdout
			      The program that formail was trying to pipe into
			      didn't  accept  all the data formail sent to it;
			      this diagnostic can be suppressed by the -q  op-
			      tion.

       Duplicate key found: x The  Message-ID  or sender x in this message was
			      found in the idcache;  this  diagnostic  can  be
			      suppressed by the -q option.

       Failed to execute "x"  Program not in path, or not executable.

       File table full	      Too many open files on this machine.

       Invalid field-name: "x"
			      The  specified  field-name  "x" contains control
			      characters, or cannot be	a  partial  field-name
			      for this option.

WARNINGS
       You can save yourself and others a lot of grief if you try to avoid us-
       ing this autoreply feature on mails coming through  mailinglists.   De-
       pending	on  the	 format of the incoming mail (which in turn depends on
       both the original sender's mail agent and the mailinglist  setup)  for-
       mail  could  decide to generate an autoreply header that replies to the
       list.

       In the tradition of UN*X utilities, formail will do  exactly  what  you
       ask  it	to,  even if it results in a non-RFC822 compliant message.  In
       particular, formail will let you generate header fields whose name ends
       in  a  space instead of a colon.	 While this is correct for the leading
       `From ' line, that line is not a header field so much  as  the  message
       separator  for the mbox mailbox format.	Multiple occurrences of such a
       line or any other colonless header field will  be  considered  by  many
       mail programs, including formail itself, as the beginning of a new mes-
       sage.  Others will consider the message	to  be	corrupt.   Because  of
       this, you should not use the -i option with the `From ' line as the re-
       sulting renamed line, `Old-From ', will probably not do what  you  want
       it  to.	 If you want to save the original `From ' line, rename it with
       the -R option to a legal header field such as `X-From_:'.

BUGS
       When formail has to generate a leading `From ' line  it	normally  will
       contain	the  current date.  If formail is given the option `-a Date:',
       it will use the date from the `Date:' field in the header (if present).
       However,	 since formail copies it verbatim, the format will differ from
       that expected by most mail readers.

       If formail is instructed to delete or rename the leading `From '	 line,
       it  will not automatically regenerate it as usual.  To force formail to
       regenerate it in this case, include -a 'From '.

       If formail is not called as the first program in a pipe and it is  told
       to split up the input in several messages, then formail will not termi-
       nate until the program it receives the input from closes its output  or
       terminates itself.

       If  formail  is instructed to generate an autoreply mail, it will never
       put more than one address in the `To:' field.

MISCELLANEOUS
       Formail is eight-bit clean.

       When formail has to determine the sender's address, every  RFC822  con-
       forming	mail  address  is allowed.  Formail will always strip down the
       address to its minimal form (deleting  excessive	 comments  and	white-
       space).

       The regular expression that is used to find `real' postmarks is:
	      "\n\nFrom [\t ]*[^\t\n ]+[\t ]+[^\n\t ]"

       If  a Content-Length: field is found in a header, formail will copy the
       number of specified bytes in the body verbatim before resuming the reg-
       ular  scanning for message boundaries (except when splitting digests or
       Berkeley mailbox format is assumed).

       Any header lines immediately following the leading `From	 '  line  that
       start  with `>From ' are considered to be a continuation of the `From '
       line.  If instructed to rename the `From ' line,	 formail  will	change
       each  leading  `>'  into a space, thereby transforming those lines into
       normal RFC822 continuations.

NOTES
       Calling up formail with the -h or -? options will cause it to display a
       command-line help page.

SOURCE
       This  program  is  part of the procmail mail-processing-package (v3.22)
       available at http://www.procmail.org/ or ftp.procmail.org in  pub/proc-
       mail/.

MAILINGLIST
       There exists a mailinglist for questions relating to any program in the
       procmail package:
	      <procmail-users@procmail.org>
		     for submitting questions/answers.
	      <procmail-users-request@procmail.org>
		     for subscription requests.

       If you would like to stay informed  about  new  versions	 and  official
       patches send a subscription request to
	      procmail-announce-request@procmail.org
       (this is a readonly list).

AUTHORS
       Stephen R. van den Berg
	      <srb@cuci.nl>
       Philip A. Guenther
	      <guenther@sendmail.com>



BuGless				  2001/08/04			    FORMAIL(1)