File Coverage

=head1 NAME

Log::Abstraction - Logging Abstraction Layer

=head1 VERSION

0.26

=cut

=head1 SYNOPSIS

  use Log::Abstraction;

  my $logger = Log::Abstraction->new(logger => 'logfile.log');

  $logger->debug('This is a debug message');
  $logger->info('This is an info message');
  $logger->notice('This is a notice message');
  $logger->trace('This is a trace message');
  $logger->warn({ warning => 'This is a warning message' });

=head1 DESCRIPTION

The C<Log::Abstraction> class provides a flexible logging layer on top of different types of loggers,
including code references, arrays, file paths, and objects.
It also supports logging to syslog if configured.

=head1 METHODS

=head2 new

    my $logger = Log::Abstraction->new(%args);

Creates a new C<Log::Abstraction> object.

The argument can be a hash,
a reference to a hash or the C<logger> value.
The following arguments can be provided:

=over

=item * C<carp_on_warn>

If set to 1,
and C<logger> is not given,
call C<Carp:carp> on C<warn()>.

Causes C<error()> to C<carp> if C<croak_on_error> is not given.

=item * C<croak_on_error>

If set to 1,
and C<logger> is not given,
call C<Carp:croak> on C<error()>.

=item * C<config_file>

Points to a configuration file which contains the parameters to C<new()>.
The file can be in any common format,
including C<YAML>, C<XML>, and C<INI>.
This allows the parameters to be set at run time.

On a non-Windows system,
the class can be configured using environment variables starting with C<"Log::Abstraction::">.
For example:

  export Log::Abstraction::script_name=foo

It doesn't work on Windows because of the case-insensitive nature of that system.

=item * C<level>

The minimum level at which to log something,
the default is "warning".

=item * C<logger>

A logger can be one or more of:

=over

=item * a code reference

The code will be called with a hashref containing:

=over

=item * class

=item * file

=item * line

=item * level

=item * message - an arrayref of messages

=back

=item * an object

=item * a hash of options

=item * sendmail - send higher priority messages to an email address

To send an e-mail,
you need L<require Email::Simple>, L<require Email::Sender::Simple> and L<Email::Sender::Transport::SMTP>.

=item * array - a reference to an array

=item * fd - containing a file descriptor to log to

=item * file - containing the filename

=back

Defaults to L<Log::Log4perl>.
In that case,
the argument 'verbose' to new() will raise the logging level.

=item * C<format>

The format of the message.
Expands:

=over

=item * %callstack%

=item * %level%

=item * %class%

=item * %message%

=item * %timestamp%

=%item * %env_foo%

Replaces with C<$ENV{foo}>

=back

=item * C<syslog>

A hash reference for syslog configuration.
Only warnings and above will be sent to syslog.
This restriction should be lifted in the future,
since it's reasonable to send notices and above to the syslog.

=item * C<script_name>

The name of the script.
It's needed when C<syslog> is given,
if none is passed, the value is guessed.

=back

Clone existing objects with or without modifications:

    my $clone = $logger->new();

=cut

=head2 _sanitize_email_header

    my $clean_value = _sanitize_email_header($raw_value);

Internal routine to remove carriage return and line feed characters from an email header value to prevent header injection or formatting issues.

=over 4

=item * Input

Takes a single scalar value, typically a string representing an email header field.

=item * Behavior

If the input is undefined, returns `undef`. Otherwise, removes all newline characters (`\n`), carriage returns (`\r`), and CRLF pairs from the string.

=item * Output

Returns the sanitized string with CR/LF characters removed.

=back

=head3 FORMAL SPECIFICATION

If the input is undefined (∅), the output is also undefined (∅).

If the input is defined, the result is a defined string with CR and LF characters removed.

    [CHAR]

    CR, LF : CHAR
    CR == '\r'
    LF == '\n'

    STRING == seq CHAR

    SanitizeEmailHeader
        raw?: STRING
        sanitized!: STRING
        -------------------------------------------------
        sanitized! = [ c : raw? | c ≠ CR ∧ c ≠ LF ]

=cut

=head2 level

Get/set the minimum level to log at.
Returns the current level, as an integer.

=cut

=head2  is_debug

Are we at a debug level that will emit debug messages?
For compatibility with L<Log::Any>.

=cut

=head2 messages

Return all the messages emitted so far

=cut

=head2 debug

  $logger->debug(@messages);

Logs a debug message.

=cut

=head2 info

  $logger->info(@messages);

Logs an info message.

=cut

=head2 notice

  $logger->notice(@messages);

Logs a notice message.

=cut

=head2 error

    $logger->error(@messages);

Logs an error message. This method also supports logging to syslog if configured.
If not logging mechanism is set,
falls back to C<Carp>.

=cut

=head2 trace

  $logger->trace(@messages);

Logs a trace message.

=cut

=head2 warn

  $logger->warn(@messages);
  $logger->warn(\@messages);
  $logger->warn(warning => \@messages);

Logs a warning message. This method also supports logging to syslog if configured.
If not logging mechanism is set,
falls back to C<Carp>.

=cut

=head2 _high_priority

Helper to handle important messages.

=cut

=head1 AUTHOR

Nigel Horne C<njh@nigelhorne.com>

=head1 SEE ALSO

=over 4

=item * Test coverage report: L<https://nigelhorne.github.io/Log-Abstraction/coverage/>

=back

=head1 SUPPORT

This module is provided as-is without any warranty.

Please report any bugs or feature requests to C<bug-log-abstraction at rt.cpan.org>,
or through the web interface at
L<http://rt.cpan.org/NoAuth/ReportBug.html?Queue=Log-Abstraction>.
I will be notified, and then you'll
automatically be notified of progress on your bug as I make changes.

You can find documentation for this module with the perldoc command.

    perldoc Log::Abstraction

You can also look for information at:

=over 4

=item * MetaCPAN

L<https://metacpan.org/dist/Log-Abstraction>

=item * RT: CPAN's request tracker

L<https://rt.cpan.org/NoAuth/Bugs.html?Dist=Log-Abstraction>

=item * CPAN Testers' Matrix

L<http://matrix.cpantesters.org/?dist=Log-Abstraction>

=item * CPAN Testers Dependencies

L<http://deps.cpantesters.org/?module=Log::Abstraction>

=back

=head1 COPYRIGHT AND LICENSE

Copyright (C) 2025 Nigel Horne

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

=cut