NAME
procmailrc - procmail rcfile
SYNOPSIS
$HOME/.procmailrc
DESCRIPTION
For a quick start, see NOTES at the end of the procmail(1)
man page.
The rcfile can contain a mixture of environment variable
assignments (some of which have special meanings to
procmail), and recipes. In their most simple appearance,
the recipes are simply one line regular expressions that are
searched for in the header of the arriving mail, the first
recipe that matches is used to determine where the mail has
to go (usually a file). If processing falls off the end of
the rcfile, procmail will deliver the mail to $DEFAULT.
There are two kinds of recipes: delivering and non-
delivering recipes. If a delivering recipe is found to
match, procmail considers the mail (you guessed it)
delivered and will cease processing the rcfile after having
successfully executed the action line of the recipe. If a
non-delivering recipe is found to match, processing of the
rcfile will continue after the action line of this recipe
has been executed.
Delivering recipes are those that cause header and/or body
of the mail to be written into a file, absorbed by a program
or forwarded to a mailaddress.
Non-delivering recipes are those that cause the output of a
program or filter to be captured back by procmail or those
that start a nesting block.
You can tell procmail to treat a delivering recipe as if it
were a non-delivering recipe by specifying the `c' flag on
such a recipe. This will make procmail generate a carbon
copy of the mail by delivering it to this recipe, yet
continue processing the rcfile.
By using any number of recipes you can presort your mail
extremely straightforward into several mailfolders. Bear in
mind though that the mail can arrive concurrently in these
mailfolders (if several procmail programs happen to run at
the same time, not unlikely if a lot of mail arrives), to
make sure this does not result in a mess, proper use of
lockfiles is highly recommended.
The environment variable assignments and recipes can be
freely intermixed in the rcfile. If any environment variable
has a special meaning to procmail, it will be used
appropriately the moment it is parsed. (i.e. you can change
the current directory whenever you want by specifying a new
MAILDIR, switch lockfiles by specifying a new LOCKFILE,
change the umask at any time, etc., the possibilities are
endless :-).
The assignments and substitutions of these environment
variables are handled exactly like in sh(1) (that includes
all possible quotes and escapes), with the added bonus that
blanks around the '=' sign are ignored and that, if an
environment variable appears without a trailing '=', it will
be removed from the environment. Any program in backquotes
started by procmail will have the entire mail at its stdin.
Comments
A word beginning with # and all the following characters up
to a NEWLINE are ignored. This does not apply to condition
lines, which cannot be commented.
Recipes
A line starting with ':' marks the beginning of a recipe.
It has the following format:
:0 [flags] [ : [locallockfile] ]
<zero or more conditions (one per line)>
<exactly one action line>
Conditions start with a leading `*', everything after that
character is passed on to the internal egrep literally,
except for leading and trailing whitespace. These regular
expressions are completely compatible to the normal egrep(1)
extended regular expressions. See also Extended regular
expressions.
Conditions are anded; if there are no conditions the result
will be true be default.
Flags can be any of the following:
H Egrep the header (default).
B Egrep the body.
D Tell the internal egrep to distinguish between upper
and lower case (contrary to the default which is to
ignore case).
A This recipe will depend on the last preceding recipe
(on the current block-nesting level) without the `A' or
`a' flag. This allows you to chain actions that depend
on a common condition.
a Has the same meaning as the `A' flag, but will depend
on the successful completion of the immediately
preceding recipe as well.
E This recipe only executes if the immediately preceding
recipe was not executed. Execution of this recipe also
disables any immediately following recipes with the 'E'
flag. This allows you to specify `else if' actions.
e This recipe only executes if the immediately preceding
recipe failed. This allows you to specify `error'
actions.
h Feed the header to the pipe (default).
b Feed the body to the pipe (default).
f Consider the pipe as a filter.
c Generate a carbon copy of this mail. This only makes
sense on delivering recipes. The only non-delivering
recipe this flag has an effect on is on a nesting
block, in order to generate a carbon copy this will
clone the running procmail process (lockfiles will not
be inherited), whereas the clone will proceed as usual
and the parent will jump across the block.
w Wait for the filter or program to finish and check its
exitcode (normally ignored); if the filter is
unsuccessful, then the text will not have been
filtered.
W Has the same meaning as the `w' flag, but will suppress
any `Program failure' message.
i Ignore any write errors on this recipe (i.e. usually
due to an early closed pipe).
r Raw mode, do not try to ensure the mail ends with an
empty line, write it out as is.
There are some special conditions you can use that are not
straight regular expressions. To select them, the condition
must start with:
! Invert the condition.
$ Evaluate the remainder according to sh(1) substitution
rules inside double quotes, skip leading whitespace,
then reparse it.
? Use the exitcode of the specified program.
< Check if the total length of the mail is shorter than
the specified (in decimal) number of bytes.
> Analogous to '<'.
variablename ??
Match the remainder against the value of this
environment variable (this cannot be a pseudo
variable). Special cases are `B', `H', `HB' and `BH',
which merely override the default header/body search
area defined for this recipe.
\ To quote any of the above at the start of the line.
Local lockfile
If you put a second (trailing) ':' on the first recipe line,
then procmail will use a locallockfile (for this recipe
only). You can optionally specify the locallockfile to use;
if you don't however, procmail will use the destination
filename (or the filename following the first '>>') and will
append $LOCKEXT to it.
Recipe action line
The action line can start with the following characters:
! Forwards to all the specified mail addresses.
| Starts the specified program, possibly in $SHELL if any
of the characters $SHELLMETAS are spotted. You can
optionally prepend this pipe symbol with variable=,
which will cause stdout of the program to be captured
in the environment variable. If you specify just this
pipe symbol, without any program, then procmail will
pipe the mail to stdout.
{ Followed by at least one space, tab or newline will
mark the start of a nesting block. Everything up till
the next closing brace will depend on the conditions
specified for this recipe. Unlimited nesting is
permitted. The closing brace exists merely to delimit
the block, it will not cause procmail to terminate in
any way. If the end of a block is reached processing
will continue as usual after the block. On a nesting
block, the flags `H' and `B' only affect the conditions
leading up to the block, the flags `h' and `b' have no
effect whatsoever.
Anything else will be taken as a mailbox name (either a
filename or a directory, absolute or relative to the current
directory (see MAILDIR)). If it is a (possibly yet
inexistent) filename, the mail will be appended to it.
If it is a directory, the mail will be delivered to a newly
created, guaranteed to be unique file named $MSGPREFIX* in
the specified directory. If the directory name ends in
"/.", then this directory is presumed to be an MH folder;
i.e. procmail will use the next number it finds available.
When procmail is delivering to directories, you can specify
multiple directories to deliver to (using hardlinks).
Environment variable defaults
LOGNAME, HOME and SHELL
Your (the recipient's) defaults
SHELLMETAS &|<>~;?*[
SHELLFLAGS -c
ORGMAIL /usr/spool/mail/$LOGNAME
(Unless -m has been specified, in
which case it is unset)
MAILDIR $HOME/
(Unless the name of the first
successfully opened rcfile starts with
`./', in which case it defaults to
`.')
DEFAULT $ORGMAIL
MSGPREFIX msg.
SENDMAIL /usr/lib/sendmail
HOST The current hostname
COMSAT no
(If an rcfile is specified on the
command line)
LOCKEXT .lock
Other cleared or preset environment variables are IFS, ENV,
PWD, PATH=$HOME/bin:/bin:/usr/ucb:/usr/local/bin
:/usr/bin/X11 and USER=$LOGNAME.
Environment
Before you get lost in the multitude of environment
variables, keep in mind that all of them have reasonable
defaults.
MAILDIR Current directory while procmail is executing
(that means that all paths are relative to
$MAILDIR).
DEFAULT Default mailbox file (if not told otherwise,
procmail will dump mail in this mailbox).
Procmail will automatically use $DEFAULT$LOCKEXT
as lockfile prior to writing to this mailbox.
You do not need to set this variable, since it
already points to the standard system mailbox.
LOGFILE This file will also contain any error or
diagnostic messages from procmail (normally none
:-) or any other programs started by procmail.
If this file is not specified, any diagnostics
or error messages will be mailed back to the
sender. See also LOGABSTRACT.
VERBOSE You can turn on extended diagnostics by setting
this variable to `yes' or `on', to turn it off
again set it to `no' or `off'.
LOGABSTRACT Just before procmail exits it logs an abstract
of the delivered message in $LOGFILE showing the
`From ' and `Subject:' fields of the header,
what folder it finally went to and how long (in
bytes) the message was. By setting this
variable to `no', generation of this abstract is
suppressed. If you set it to `all', procmail
will log an abstract for every successful
delivering recipe it processes.
LOG Anything assigned to this variable will be
appended to $LOGFILE.
ORGMAIL Usually the system mailbox (ORiGinal MAILbox).
If, for some obscure reason (like `filesystem
full') the mail could not be delivered, then
this mailbox will be the last resort. If
procmail fails to save the mail in here (deep,
deep trouble :-), then the mail will bounce back
to the sender.
LOCKFILE Global semaphore file. If this file already
exists, procmail will wait until it has gone
before proceeding, and will create it itself
(cleaning it up when ready, of course). If more
than one lockfile are specified, then the
previous one will be removed before trying to
create the new one. The use of a global
lockfile is discouraged, whenever possible use
locallockfiles (on a per recipe basis) instead.
LOCKEXT Default extension that is appended to a
destination file to determine what local
lockfile to use (only if turned on, on a per-
recipe basis).
LOCKSLEEP Number of seconds procmail will sleep before
retrying on a lockfile (if it already existed);
if not specified, it defaults to 8 seconds.
LOCKTIMEOUT Number of seconds that have to have passed since
a lockfile was last modified/created before
procmail decides that this must be an
erroneously leftover lockfile that can be
removed by force now. If zero, then no timeout
will be used and procmail will wait forever
until the lockfile is removed; if not specified,
it defaults to 1024 seconds. This variable is
useful to prevent indefinite hangups of
sendmail/procmail. Procmail is immune to clock
skew across machines.
TIMEOUT Number of seconds that have to have passed
before procmail decides that some child it
started must be hanging. The offending program
will receive a TERMINATE signal from procmail,
and processing of the rcfile will continue. If
zero, then no timeout will be used and procmail
will wait forever until the child has
terminated; if not specified, it defaults to 960
seconds.
MSGPREFIX Filename prefix that is used when delivering to
a directory (not used when delivering to an MH
directory).
HOST If this is not the hostname of the machine,
processing of the current rcfile will
immediately cease. If other rcfiles were
specified on the command line, processing will
continue with the next one. If all rcfiles are
exhausted, the program will terminate, but will
not generate an error (i.e. to the mailer it
will seem that the mail has been delivered).
UMASK The name says it all (if it doesn't, then forget
about this one :-). Anything assigned to UMASK
is taken as an octal number. If not specified,
the umask defaults to 077. If the umask permits
o+x, all the mailboxes procmail delivers to
directly will receive an o+x mode change. This
can be used to check if new mail arrived.
SHELLMETAS If any of the characters in SHELLMETAS appears
in the line specifying a filter or program, the
line will be fed to $SHELL instead of being
executed directly.
SHELLFLAGS Any invocation of $SHELL will be like:
"$SHELL" "$SHELLFLAGS" "$*";
SENDMAIL If you're not using the forwarding facility
don't worry about this one. It specifies the
program being called to forward any mail.
It gets invoked as: "$SENDMAIL" "$@";
NORESRETRY Number of retries that are to be made if any
`process table full', `file table full', `out of
memory' or `out of swap space' error should
occur. If this number is negative, then
procmail will retry indefinitely; if not
specified, it defaults to 4 times. The retries
occur with a $SUSPEND second interval. The idea
behind this is, that if e.g. the swap space has
been exhausted or the process table is full,
usually several other programs will either
detect this as well and abort or crash 8-),
thereby freeing valuable resources for procmail.
SUSPEND Number of seconds that procmail will pause if it
has to wait for something that is currently
unavailable (memory, fork, etc.); if not
specified, it will default to 16 seconds. See
also: LOCKSLEEP.
LINEBUF Length of the internal line buffers, cannot be
set smaller than 128. All lines read from the
rcfile should not exceed $LINEBUF characters
before and after expansion. If not specified,
it defaults to 2048. This limit, of course,
does not apply to the mail itself, which can
have arbitrary line lengths, or could be a
binary file for that matter.
DELIVERED If set to `yes' procmail will pretend (to the
mail agent) the mail has been delivered. If
mail cannot be delivered after having met this
assignment (set to `yes'), the mail will be lost
(i.e. it will not bounce).
TRAP When procmail terminates it will execute the
contents of this variable. A copy of the mail
can be read from stdin. Any output produced by
this command will be appended to $LOGFILE.
Possible uses for TRAP are: removal of temporary
files, logging customised abstracts, etc. See
also EXITCODE and LOGABSTRACT.
EXITCODE When procmail terminates and this variable has
been set to a positive numeric value, procmail
will use this as the exitcode. If this variable
is set but empty, procmail will set the exitcode
to whatever the TRAP program returns. If this
variable has not been set, procmail will set it
shortly before calling up the TRAP program.
LASTFOLDER This variable is assigned to by procmail
whenever it is delivering to a folder or
program. It always contains the name of the
last folder (or program) procmail delivered to.
MATCH This variable is assigned to by procmail
whenever it is told to extract text from a
matching regular expression. It will contain
all text matching the regular expression past
the `\/' token.
SHIFT Assigning a positive value to this variable has
the same effect as the `shift' command in sh(1).
This command is most useful to extract extra
arguments passed to procmail when acting as a
generic mailfilter.
INCLUDERC Names an rcfile (relative to the current
directory) which will be included here as if it
were part of the current rcfile. Unlimited
nesting is permitted.
COMSAT Comsat(8)/biff(1) notification is on by default,
it can be turned off by setting this variable to
`no'. Alternatively the biff-service can be
customised by setting it to either `service@',
`@hostname', or `service@hostname'. When not
specified it defaults to biff@localhost.
DROPPRIVS If set to `yes' procmail will drop all
privileges it might have had (suid or sgid).
This is only useful if you want to guarantee
that the bottom half of the /etc/procmailrc file
is executed on behalf of the recipient.
Extended regular expressions
The following tokens are known to both the procmail internal
egrep and the standard egrep(1):
^ Start of a line.
$ End of a line.
. Any character except a newline.
a* Any sequence of zero or more a's.
a+ Any sequence of one or more a's.
a? Either zero or one a.
[^-a-d] Any character which is not either a dash, a, b, c,
d or newline.
de|abc Either the sequence `de' or `abc'.
(abc)* Zero or more times the sequence `abc'.
These were only samples, of course, any more complex
combination is valid as well.
The following token meanings are special procmail
extensions:
^ or $ Match a newline (for multiline matches).
^^ Anchor the expression at the very start of the
search area, or if encountered at the end of the
expression, anchor it at the very end of the
search area.
\< or \> Match the character before or after a word. They
are merely a shorthand for `[^a-zA-Z0-9_]', but
can also match newlines. Since they match actual
characters, they are only suitable to delimit
words, not to delimit inter-word space.
\/ Splits the expression in two parts. Everything
matching the right part will be assigned to the
MATCH environment variable.
EXAMPLES
Look in the procmailex(5) man page.
CAVEATS
Continued lines in an action line that specifies a program
always have to end in a backslash, even if the underlying
shell would not need or want the backslash to indicate
continuation. This is due to the two pass parsing process
needed (first procmail, then the shell (or not, depending on
SHELLMETAS)).
Don't put comments on the regular expression condition lines
in a recipe, these lines are fed to the internal egrep
literally (except for continuation backslashes at the end of
a line).
Leading whitespace on continued regular expression condition
lines is usually ignored (so that they can be indented), but
not on continued condition lines that are evaluated
according to the sh(1) substitution rules inside double
quotes.
Watch out for deadlocks when doing unhealthy things like
forwarding mail to your own account. Deadlocks can be
broken by proper use of LOCKTIMEOUT.
Any default values that procmail has for some environment
variables will always override the ones that were already
defined. If you really want to override the defaults, you
either have to put them in the rcfile or on the command line
as arguments.
Environment variables set inside the shell-interpreted-`|'
action part of a recipe will not retain their value after
the recipe has finished since they are set in a subshell of
procmail. To make sure the value of an environment variable
is retained you have to put the assignment to the variable
before the leading `|' of a recipe, so that it can capture
stdout of the program.
If you specify only a `h' or a `b' flag on a delivering
recipe, and the recipe matches, then, unless the `c' flag is
present as well, the body respectively the header of the
mail will be silently lost.
SEE ALSO
procmail(1), procmailsc(5), procmailex(5), sh(1), csh(1),
mail(1), mailx(1), binmail(1), uucp(1), aliases(5),
sendmail(8), egrep(1), grep(1), biff(1), comsat(8),
lockfile(1), formail(1)
BUGS
The only substitutions of environment variables that can be
handled by procmail itself are of the type $name, ${name},
${name:-text}, ${name:+text}, ${name-text}, ${name+text},
$#, $n, $$, $?, $_, $- and $=; whereas $_ will be substitut-
ed by the name of the current rcfile, $- by $LASTFOLDER and
$= will contain the score of the last recipe. When the -a
or -m options are used, "$@" will expand to respectively the
specified argument (list); but only when passed as in the
argument list to a program.
Procmail does not support the expansion of `~'.
A line buffer of length $LINEBUF is used when processing the
rcfile, any expansions have to fit within this limit; if
they don't, behaviour is undefined.
If the global lockfile has a relative path, and the current
directory is not the same as when the global lockfile was
created, then the global lockfile will not be removed if
procmail exits at that point (remedy: use absolute paths to
specify global lockfiles).
A locallockfile on the recipe that marks the start of a
nested block does not work as expected.
When capturing stdout from a recipe into an environment
variable, exactly one trailing newline will be stripped.
MISCELLANEOUS
If the regular expression contains `^TO' it will be substi-
tuted by `(^((Original-)?(Resent-)?(To|Cc|Bcc)|(X-Envelope
|Apparently(-Resent)?)-To):(.*[^a-zA-Z])?)', which should
catch all destination specifications.
If the regular expression contains `^FROM_DAEMON' it will be
substituted by `(^(Precedence:.*(junk|bulk|list)|(((Resent-
)?(From|Sender)|X-Envelope-From):|>?From )(.*[^(.%@a-z0-
9])?(Post(ma?(st(e?r)?|n)|office)|(send)?Mail(er)?|daemon
|mmdf|root|n?uucp|smtp|response|LISTSERV|owner|request|bounce
|serv(ices?|er)|Admin(istrator)?)([^).!:a-z0-9].*)?$[^>]))',
which should catch mails coming from most daemons (how's
that for a regular expression :-).
If the regular expression contains `^FROM_MAILER' it will be
substituted by `(^(((Resent-)?(From|Sender)|X-Envelope-From):
|>?From )(.*[^(.%@a-z0-9])?(Post(ma(st(er)?|n)|office)
|(send)?Mail(er)?|daemon|mmdf|root|n?uucp|smtp|response
|serv(ices?|er)|Admin(istrator)?)([^).!:a-z0-9].*)?$[^>])'
(a stripped down version of `^FROM_DAEMON'), which should
catch mails coming from most mailer-daemons.
When assigning boolean values to variables like VERBOSE,
DELIVERED or COMSAT, procmail accepts as true every string
starting with: a non-zero value, `on', `y', `t' or `e'.
False is every string starting with: a zero value, `off',
`n', `f' or `d'.
If the action line of a recipe specifies a program, a sole
backslash-newline pair in it on an otherwise empty line will
be converted into a newline.
NOTES
Since unquoted leading whitespace is generally ignored in
the rcfile you can indent everything to taste.
The leading `|' on the action line to specify a program or
filter is stripped before checking for $SHELLMETAS.
Files included with the INCLUDERC directive containing only
environment variable assignments can be shared with sh.
For really complicated processing you can even consider cal-
ling procmail recursively.
AUTHOR
Stephen R. van den Berg at RWTH-Aachen, Germany
berg@pool.informatik.rwth-aachen.de