=encoding utf8

=head1 NAME

Log::Report::Dispatcher::File - send messages to a file or file-handle

=head1 INHERITANCE

 Log::Report::Dispatcher::File
   is a Log::Report::Dispatcher

=head1 SYNOPSIS

  dispatcher Log::Report::Dispatcher::File => 'stderr',
    to => \*STDERR, accept => 'NOTICE-';

  # close a dispatcher
  dispatcher close => 'stderr';

  # let dispatcher open and close the file
  dispatcher FILE => 'mylog', to => '/var/log/mylog',
    charset => 'utf-8';
  ...
  dispatcher close => 'mylog';  # will close file

  # open yourself, then also close yourself
  open OUT, ">:encoding('iso-8859-1')", '/var/log/mylog'
      or fault "...";
  dispatcher FILE => 'mylog', to => \*OUT;
  ...
  dispatcher close => 'mylog';
  close OUT;

  # dispatch into a scalar
  my $output = '';
  open $outfile, '>', \$output;
  dispatcher FILE => 'into-scalar', to => \$outfile;
  ...
  dispatcher close => 'into-scalar';
  print $output;

=head1 DESCRIPTION

This basic file logger accepts an file-handle or filename as destination.

[1.00] writing to the file protected by a lock, so multiple processes
can write to the same file.

Extends L<"DESCRIPTION" in Log::Report::Dispatcher|Log::Report::Dispatcher/"DESCRIPTION">.

=head1 METHODS

Extends L<"METHODS" in Log::Report::Dispatcher|Log::Report::Dispatcher/"METHODS">.

=head2 Constructors

Extends L<"Constructors" in Log::Report::Dispatcher|Log::Report::Dispatcher/"Constructors">.

=over 4

=item $obj-E<gt>B<close>()

Only when initiated with a FILENAME, the file will be closed.  In any
other case, nothing will be done.
Improves base, see L<Log::Report::Dispatcher/"Constructors">

=item $class-E<gt>B<new>($type, $name, %options)

Inherited, see L<Log::Report::Dispatcher/"Constructors">

 -Option       --Defined in             --Default
  accept         Log::Report::Dispatcher  depend on mode
  charset        Log::Report::Dispatcher  LC_CTYPE
  format                                  <adds timestamp>
  format_reason  Log::Report::Dispatcher  'LOWERCASE'
  locale         Log::Report::Dispatcher  <system locale>
  mode           Log::Report::Dispatcher  'NORMAL'
  replace                                 false
  to                                      <required>

=over 2

=item accept => REASONS

=item charset => CHARSET

=item format => CODE|'LONG'

[1.00] process each printed line.  By default, this adds a timestamp,
but you may want to add hostname, process number, or more.

  format => sub { '['.localtime().'] '.$_[0] }
  format => sub { shift }   # no timestamp
  format => 'LONG'

The first parameter to format is the string to print; it is already
translated and trailed by a newline.  The second parameter is the
text-domain (if known).

[1.10] As third parameter, you get the message raw object as well (maybe
you want to use the message context?)

[1.19] After the three positional parameters, there may be a list
of pairs providing additional facts about the exception.  It may
contain C<location> information.

The "LONG" format is equivalent to:

  my $t = strftime "%FT%T", gmtime;
  "[$t $$] $_[1] $_[0]"

Use of context:

  format => sub { my ($msgstr, $domain, $msg, %more) = @_;
     my $host = $msg->context->{host};
     "$host $msgstr";
  }

=item format_reason => 'UPPERCASE'|'LOWERCASE'|'UCFIRST'|'IGNORE'|CODE

=item locale => LOCALE

=item mode => 'NORMAL'|'VERBOSE'|'ASSERT'|'DEBUG'|0..3

=item replace => BOOLEAN

Only used in combination with a C<to> filename: throw away the old file
if it exists.  Probably you wish to append to existing information.

Use the locale setting by default, which is LC_CTYPE or LC_ALL or LANG
(in that order).  If these contain a character-set which Perl understands,
then that is used, otherwise silently ignored.

=item to => $file|$fh|OBJECT|CODE

You can either specify a C<$file> by name, which is opened in append mode with
autoflush on. Or pass any kind of file handle C<$fh>, or some OBJECT which
implements a C<print()> method. You probably want to have autoflush
enabled on your file-handles.

When cleaning-up the dispatcher, the file will only be closed in case
of a named C<$file>.

[1.10] When you pass a CODE, then for each log message the function is
called with two arguments: this dispatcher object and the message object.
In some way (maybe via the message context) you have to determine the
log filename.  This means that probably many log-files are open at the
same time.

  # configuration time
  dispatcher FILE => 'logfile', to =>
     sub { my ($disp, $msg) = @_; $msg->context->{logfile} };

  # whenever you want to change the logfile
  textdomain->updateContext(logfile => '/var/log/app');
  (textdomain 'mydomain')->setContext(logfile => '/var/log/app');

  # or
  error __x"help", _context => {logfile => '/dev/tty'};
  error __x"help", _context => "logfile=/dev/tty";

=back

=back

=head2 Accessors

Extends L<"Accessors" in Log::Report::Dispatcher|Log::Report::Dispatcher/"Accessors">.

=over 4

=item $obj-E<gt>B<filename>()

Returns the name of the opened file, or C<undef> in case this dispatcher
was started from a file-handle or file-object.

=item $obj-E<gt>B<format>()

Z<>

=item $obj-E<gt>B<isDisabled>()

Inherited, see L<Log::Report::Dispatcher/"Accessors">

=item $obj-E<gt>B<mode>()

Inherited, see L<Log::Report::Dispatcher/"Accessors">

=item $obj-E<gt>B<name>()

Inherited, see L<Log::Report::Dispatcher/"Accessors">

=item $obj-E<gt>B<needs>( [$reason] )

Inherited, see L<Log::Report::Dispatcher/"Accessors">

=item $obj-E<gt>B<output>($msg)

Returns the file-handle to write the log lines to. [1.10] This may
depend on the C<$msg> (especially message context)

=item $obj-E<gt>B<type>()

Inherited, see L<Log::Report::Dispatcher/"Accessors">

=back

=head2 File maintenance

=over 4

=item $obj-E<gt>B<rotate>($filename|CODE)

[1.00] Move the current file to C<$filename>, and start a new file.

=back

=head2 Logging

Extends L<"Logging" in Log::Report::Dispatcher|Log::Report::Dispatcher/"Logging">.

=over 4

=item $any-E<gt>B<addSkipStack>(@CODE)

Inherited, see L<Log::Report::Dispatcher/"Logging">

=item $any-E<gt>B<collectLocation>()

Inherited, see L<Log::Report::Dispatcher/"Logging">

=item $any-E<gt>B<collectStack>( [$maxdepth] )

Inherited, see L<Log::Report::Dispatcher/"Logging">

=item $obj-E<gt>B<log>(HASH-$of-%options, $reason, $message, $domain)

Inherited, see L<Log::Report::Dispatcher/"Logging">

=item $obj-E<gt>B<skipStack>()

Inherited, see L<Log::Report::Dispatcher/"Logging">

=item $any-E<gt>B<stackTraceLine>(%options)

Inherited, see L<Log::Report::Dispatcher/"Logging">

=item $obj-E<gt>B<translate>(HASH-$of-%options, $reason, $message)

Inherited, see L<Log::Report::Dispatcher/"Logging">

=back

=head1 DETAILS

Extends L<"DETAILS" in Log::Report::Dispatcher|Log::Report::Dispatcher/"DETAILS">.

=head1 DIAGNOSTICS

=over 4

=item Error: cannot rotate log file which was opened as file-handle

Cast by rotate()

=item Fault: cannot write log into $file: $!

Cast by rotate()

=item Error: dispatcher $name needs parameter 'to'

Cast by new()

=item Fault: unable to rotate logfile $fn to $oldfn: $!

Cast by rotate()

=item Error: unknown format parameter `$what'

Cast by new()

=back

=head1 SEE ALSO

This module is part of Log-Report version 1.41,
built on September 11, 2025. Website: F<http://perl.overmeer.net/CPAN/>

=head1 LICENSE

For contributors see file ChangeLog.

This software is copyright (c) 2007-2025 by Mark Overmeer.

This is free software; you can redistribute it and/or modify it under
the same terms as the Perl 5 programming language system itself.

