Scott Wiersdorf > Mail-Procmailrc-1.09 > Mail::Procmailrc

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NAME ^

Mail::Procmailrc - An interface to Procmail recipe files

SYNOPSIS ^

  use Mail::Procmailrc;

  ## create a new procmailrc object and initialize it
  $pmrc = new Mail::Procmailrc("$HOME/.procmail/rc.spam");

  ## add a new variable
  $pmrc->push( new Mail::Procmailrc::Variable(["FOO=bar"]) );

  ## add a new recipe
  $recipe =<<'_RECIPE_';
  :0B:
  ## this will catch evil email messages
  * 1^0 xxx
  * 1^0 evil things
  * 1^0 porn and other wickedness
  * 1^0 all kinds of cursing
  * 1^0 lewdness, filth, etc\.
  /var/mail/evil
  _RECIPE_

  ## add this new recipe to our procmail rc file
  $pmrc->push( new Mail::Procmailrc::Recipe($recipe) );

  ## add another condition to our recipe (we shoulda left a scalar
  ## handle lying around, but this illustrates something useful)
  for my $obj ( @{$pmrc->rc} ) {
      ## find the recipe we just added by its 'info' string
      next unless $obj->stringify =~ /^\#\# this will catch evil email messages/m;

      ## we want to block emails about censorship, too ;o)
      push @{$obj->conditions}, '* 1^0 censor(ship|ing)?'
  }

  ## write this object to disk
  $pmrc->flush;

DESCRIPTION ^

Mail::Procmailrc can parse procmail recipe files and store the contents in an object which can be later manipulated and saved (see "CAVEATS" and "BUGS/TODO" for limitations and special conditions).

You may also start with a fresh, empty Mail::Procmailrc object, populate it with recipes and/or variables and write it to file.

Recipes and variables are written to the file in the order they're parsed and added. If you want to re-order the recipes you may do so by getting a handle on the variable or recipe list and ordering them yourself.

The Mail::Procmailrc object is primarily a list of procmail component objects (see below). When Mail::Procmailrc parses a procmail rc file, it decides which lines are variable assignments, which lines are comments, and which lines are recipes. It preserves the order in which it encounters these procmail components and stores them as a list of objects in the main Mail::Procmailrc object.

new

Creates a new Mail::Procmailrc object.

Examples:

    ## 1. in memory object
    my $pmrc = new Mail::Procmailrc;

    ## 2. parses /etc/procmailrc
    my $pmrc = new Mail::Procmailrc("/etc/procmailrc");

    ## 3. parses /etc/procmailrc, makes backup
    my $pmrc = new Mail::Procmailrc("/etc/procmailrc");
    $pmrc->file("/etc/procmailrc.bak");
    $pmrc->flush;   ## create a backup

    $pmrc->file("/etc/procmailrc");  ## future flushes will go here

    ## 4. alternative syntax: filename specified in hashref
    my $pmrc = new Mail::Procmailrc( { 'file' => '/etc/procmailrc' } );

    ## 5. alternative syntax: scalar
    my $rc =<<_FOO_;
    :0B
    * 1^0 this is not spam
    /dev/null
    _FOO_
    my $pmrc = new Mail::Procmailrc( { 'data' => $rc } );

    ## 6. alternative syntax: array reference
    my $rc =<<'_RCFILE_';
    :0c:
    /var/mail/copy
    _RCFILE_
    my @rc = map { "$_\n" } split(/\n/, $rcfile);
    $pmrc = new Mail::Procmailrc( { 'data' => \@rc } );
read

Sets the object's file attribute and parses the given file. If the file is not readable, returns undef. Normally not invoked directly.

Example:

    ## set $pmrc->file and parse
    unless( $pmrc->read('/etc/procmailrc') ) {
        die "Could not parse '/etc/procmailrc!\n";
    }
parse

Takes an array or string reference and populates the object with it.

Example:

    my $chunk =<<_RECIPE_;
    ## begin foo section
    TMPLOGFILE=\$LOGFILE
    TMPLOGABSTRACT=\$LOGABSTRACT
    TMPVERBOSE=\$VERBOSE
    
    LOGFILE=/var/log/foolog
    LOGABSTRACT=yes
    VERBOSE=no
    
    ## process the mail via foo
    :0fw
    |/usr/local/bin/foo -c /etc/mail/foo.conf
    
    LOGFILE=\$TMPLOGFILE
    LOGABSTRACT=\$TMPLOGABSTRACT
    VERBOSE=\$TMPVERBOSE
    ## end spamassassin vinstall (do not remove these comments)
    _RECIPE_

    ## make a new in-memory procmailrc file
    my $new_pmrc = new Mail::Procmailrc;
    $new_pmrc->parse($chunk);

    ## add this new procmailrc file to our existing procmailrc file
    $pmrc->push(@{$new_pmrc->rc});
    $pmrc->flush;

Alternatively, you can pass an array reference to parse:

    $new_pmrc->parse([split("\n", $chunk)]);
rc

Returns a list reference. Each item in the list is either a Variable, Literal, or Recipe object. Items are returned in the order they were originally parsed. You may assign to rc and rewrite the Mail::Procmailrc object thereby.

Example:

    ## remove foo section from recipe file
    my @tmp_rc = ();
    my $foo_section = 0;
    for my $pm_obj ( @{$pmrc->rc} ) {
        if( $pm_obj->stringify =~ /^\#\# begin foo recipes/m ) {
            $foo_section = 1;
            next;
        }
        elsif( $pm_obj->stringify =~ /^\#\# end foo recipes/m ) {
            $foo_section = 0;
            next;
        }
        elsif( $foo_section ) {
            next;
        }
        push @tmp_rc, $rc_obj;
    }
    $pmrc->rc(\@tmp_rc);
    $pmrc->flush;
recipes

Returns a listref of recipes in this object.

variables

Returns a listref of variables in this object.

literals

Returns a listref of literals in this object.

push

Pushes the dat(a|um) onto this object's internal object list. If the object being pushed is another Mail::Procmailrc object, that object's rc method is invoked first and the results are pushed.

Example:

    my $rc_objs = $old_pmrc->rc;
    $pmrc->push( @$rc_objs );
delete

Deletes an object from the main Mail::Procmailrc object:

    for my $obj ( @{$pmrc->rc} ) {
        next unless $obj->isa('Mail::Procmailrc::Recipe');

        ## I lost all my enemies when I switched to the Perl Artistic License...
        next unless $obj->info->[0] =~ /^\#\# block email from enemies/;
        $pmrc->delete($obj);
        last;
    }
file

Returns the path where this object will write when flush is invoked. If file is given an argument, the object's internal file attribute is set to this path.

flush

Writes the procmail object to disk in the file specified by the file attribute. If the file attribute is not set, flush writes to STDOUT. If a filename is given as an argument, it is set as the objects file attribute.

Examples:

    ## 1. flushes to whatever $pmrc->file is set to (STDOUT if file is unset)
    $pmrc->flush;

    ## 2. flushes to a specific file; future flushes will also go here
    $pmrc->flush('/backup/etc/procmailrc');
stringify

Returns the object in string representation.

dump

Like stringify but with nicer formatting (indentation, newlines, etc.). Suitable for inclusion in procmail rc files.

Mail::Procmailrc::Variable Objects ^

Mail::Procmailrc::Variable objects are easy to create and use. Normally, the Variable constructor is invoked by Mail::Procmailrc during parsing. If you are creating or modifying an existing procmail rc file, you might do something like this:

    my $var = new Mail::Procmailrc::Variable(["VERBOSE=off"]);

or you might wish to do it another way:

    my $var = new Mail::Procmailrc::Variable;
    $var->lval('VERBOSE');
    $var->rval('off');

You may get a handle on all Variable objects in an rc file with the variables method:

    ## change to verbose mode
    for my $var ( @{$pmrc->variables} ) {
        next unless $var->lval eq 'VERBOSE';
        $var->rval('yes');
        last;
    }

Mail::Procmailrc::Variable Methods

variable([$string])

$string, if present, is split on the first '='. The left half is assigned to lval and the right half to rval. If $string is false, lval and rval are concatenated with '=' and returned as a single string.

lval([$val])

Returns the current lvalue of the variable assignment, optionally setting it if $val is present.

rval([$val])

Returns the current rvalue of the variable assignment, optionally setting it if $val is present.

stringify

Returns the output of variable. Provides a consistent interface to all Mail::Procmailrc::* subclasses.

dump

Returns the output of stringify with a trailing newline. Suitable for inserting into a procmail rc file.

defaults([\%defaults [, $elem]])

Returns some internal object settings, currently not very useful or interesting except when parsing deeply nested recipes. Included here for completeness.

init(\@data)

Normally invoked by the constructor (new), but may be used to re-initialize an object.

Mail::Procmailrc::Literal Objects ^

Mail::Procmailrc::Literal objects are even easier to create and use than Variable objects. A Mail::Procmailrc::Literal is simply a string with a few methods wrapped around it for convenient printing.

You may get a handle on all Literal objects in an rc file with the literals method:

    ## change a comment in the rc file
    for my $lit ( @{$pmrc->literals} ) {
        next unless $lit->literal =~ /## spam follows/i;
        $lit->literal('## this is a nice spam recipe');
        last;
    }

Here is how to create a new literal:

   ## create a new literal
   my $lit = new Mail::Procmailrc::Literal('## this file is for filtering spam');

   ## same as above
   my $lit = new Mail::Procmailrc::Literal;
   $lit->literal('## this file is for filtering spam');

   ## print it
   $lit->dump;

Mail::Procmailrc::Literal Methods

literal([$string])

Get or set the literal object contents.

dump

Dump the contents of the object with a trailing newline.

Mail::Procmailrc::Recipe Objects ^

A recipe object is made up of a flags object, zero or more literal (comments or vertical whitespace) objects, zero or more condition objects, and an action object. A Mail::Procmailrc::Recipe object is made of four parts:

Normally, the Recipe object is created automatically during parsing. However, if you are constructing a new rc file or want to modify an existing procmailrc file, you will need to know a little about the Recipe object.

To create a recipe object from a string, you may do something like this:

    $recipe =<<'_RECIPE_';
    :0B:
    ## block indecent emails
    * 1^0 people talking dirty
    * 1^0 dirty persian poetry
    * 1^0 dirty pictures
    * 1^0 xxx
    /dev/null
    _RECIPE_

    $recipe_obj = new Mail::Procmailrc::Recipe($recipe);

or the more obtuse (if you happen to already have an array or reference):

    $recipe_obj = new Mail::Procmailrc::Recipe([split("\n", $recipe)]);

The entire recipe in $recipe is now contained in the $recipe_obj. You could also piece together an object part by part:

    $recipe_obj = new Mail::Procmailrc::Recipe;
    $recipe_obj->flags(':0B');
    $recipe_obj->info([q(## block indecent emails)]);
    $recipe_obj->conditions([q(* 1^0 people talking dirty),
                             q(* 1^0 dirty persian poetry),
                             q(* 1^0 dirty pictures),
                             q(* 1^0 xxx),]);
    $recipe_obj->action('/dev/null');

You can get a handle on all recipes in an rc file with the recipes method:

    my $conditions;
    for my $recipe ( @{$pmrc->recipes} ) {
        next unless $recipe->info->[0] =~ /^\s*\#\# this recipe is for spam/io;
        $conditions = $recipe->conditions;
        last;
    }
    push @$conditions, '* 1^0 this is not SPAM';  ## add another condition
    $pmrc->flush;  ## write out to file

Important Note about info

The info method of the Recipe object is really just a procmail comment (or literal elsewhere in this document), but because it appears between the flags line (e.g., ':0fw') and the conditions (e.g., * 1^0 foo), it becomes part of the recipe itself. This is terribly convenient usage because it allows you to "index" your recipes and find them later.

EXAMPLES ^

The eg directory in the Mail::Procmailrc distribution contains at least one useful program illustrating the several uses of this module. Other examples may appear here in future releases as well as the eg directory of the distribution.

CAVEATS ^

Parsing is lossy in two senses. Some formatting and stray lines may be lost. Also, array references fed to constructors will not be returned intact (i.e., data will be shifted out of them).

BUGS/TODO ^

Please let the author/maintainer know if you find any bugs (providing a regression test would also be helpful; see the testing format in the 't' directory).

ACKNOWLEDGEMENTS ^

5 Feb 2003

Erwin Lansing (erwin@lansing.dk) for 5.00503 patch and doc typo. Danke!

COPYRIGHT ^

Copyright 2002 Scott Wiersdorf.

This library is free software; you can redistribute it and/or modify it under the terms of the Perl Artistic License.

AUTHOR ^

Scott Wiersdorf <scott@perlcode.org>

SEE ALSO ^

procmail, procmailrc(5), procmailex(5), procmailsc(5)

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