log::contextual::warnlogger(3pm) [debian man page]
Log::Contextual::WarnLogger(3pm) User Contributed Perl Documentation Log::Contextual::WarnLogger(3pm) NAME
Log::Contextual::WarnLogger - Simple logger for libraries using Log::Contextual SYNOPSIS
package My::Package; use Log::Contextual::WarnLogger; use Log::Contextual qw( :log ), -default_logger => Log::Contextual::WarnLogger->new({ env_prefix => 'MY_PACKAGE' }); # warns '[info] program started' if $ENV{MY_PACKAGE_TRACE} is set log_info { 'program started' }; # no-op because info is not in levels sub foo { # warns '[debug] entered foo' if $ENV{MY_PACKAGE_DEBUG} is set log_debug { 'entered foo' }; ... } DESCRIPTION
This module is a simple logger made for libraries using Log::Contextual. We recommend the use of this logger as your default logger as it is simple and useful for most users, yet users can use "set_logger" in Log::Contextual to override your choice of logger in their own code thanks to the way Log::Contextual works. METHODS
new Arguments: "Dict[ env_prefix => Str ] $conf" my $l = Log::Contextual::WarnLogger->new({ env_prefix }); Creates a new logger object where "env_prefix" defines what the prefix is for the environment variables that will be checked for the six log levels. For example, if "env_prefix" is set to "FREWS_PACKAGE" the following environment variables will be used: FREWS_PACKAGE_UPTO FREWS_PACKAGE_TRACE FREWS_PACKAGE_DEBUG FREWS_PACKAGE_INFO FREWS_PACKAGE_WARN FREWS_PACKAGE_ERROR FREWS_PACKAGE_FATAL Note that "UPTO" is a convenience variable. If you set "FOO_UPTO=TRACE" it will enable all log levels. Similarly, if you set it to "FATAL" only fatal will be enabled. $level Arguments: @anything All of the following six methods work the same. The basic pattern is: sub $level { my $self = shift; warn "[$level] " . join qq{ }, @_; if $self->is_$level; } trace $l->trace( 'entered method foo with args ' join q{,}, @args ); debug $l->debug( 'entered method foo' ); info $l->info( 'started process foo' ); warn $l->warn( 'possible misconfiguration at line 10' ); error $l->error( 'non-numeric user input!' ); fatal $l->fatal( '1 is never equal to 0!' ); is_$level All of the following six functions just return true if their respective environment variable is enabled. is_trace say 'tracing' if $l->is_trace; is_debug say 'debuging' if $l->is_debug; is_info say q{info'ing} if $l->is_info; is_warn say 'warning' if $l->is_warn; is_error say 'erroring' if $l->is_error; is_fatal say q{fatal'ing} if $l->is_fatal; AUTHOR
See "AUTHOR" in Log::Contextual COPYRIGHT
See "COPYRIGHT" in Log::Contextual LICENSE
See "LICENSE" in Log::Contextual perl v5.10.1 2010-07-31 Log::Contextual::WarnLogger(3pm)
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Log::Dispatchouli(3pm) User Contributed Perl Documentation Log::Dispatchouli(3pm) NAME
Log::Dispatchouli - a simple wrapper around Log::Dispatch VERSION
version 2.005 SYNOPSIS
my $logger = Log::Dispatchouli->new({ ident => 'stuff-purger', facility => 'daemon', to_stdout => $opt->{print}, debug => $opt->{verbose} }) $logger->log([ "There are %s items left to purge...", $stuff_left ]); $logger->log_debug("this is extra often-ignored debugging log"); $logger->log_fatal("Now we will die!!"); DESCRIPTION
Log::Dispatchouli is a thin layer above Log::Dispatch and meant to make it dead simple to add logging to a program without having to think much about categories, facilities, levels, or things like that. It is meant to make logging just configurable enough that you can find the logs you want and just easy enough that you will actually log things. Log::Dispatchouli can log to syslog (if you specify a facility), standard error or standard output, to a file, or to an array in memory. That last one is mostly useful for testing. In addition to providing as simple a way to get a handle for logging operations, Log::Dispatchouli uses String::Flogger to process the things to be logged, meaning you can easily log data structures. Basically: strings are logged as is, arrayrefs are taken as (sprintf format, args), and subroutines are called only if needed. For more information read the String::Flogger docs. METHODS
new my $logger = Log::Dispatchouli->new(\%arg); This returns a new logger, a Log::Dispatchouli object. Valid arguments are: ident - the name of the thing logging (mandatory) to_self - log to the logger object for testing; default: false to_stdout - log to STDOUT; default: false to_stderr - log to STDERR; default: false facility - to which syslog facility to send logs; default: none to_file - log to PROGRAM_NAME.YYYYMMDD in the log path; default: false log_file - a leaf name for the file to log to with to_file log_path - path in which to log to file; defaults to DISPATCHOULI_PATH environment variable or, failing that, to your system's tmpdir log_pid - if true, prefix all log entries with the pid; default: true fail_fatal - a boolean; if true, failure to log is fatal; default: true muted - a boolean; if true, only fatals are logged; default: false debug - a boolean; if true, log_debug method is not a no-op defaults to the truth of the DISPATCHOULI_DEBUG env var quiet_fatal - 'stderr' or 'stdout' or an arrayref of zero, one, or both fatal log messages will not be logged to these (default: stderr) config_id - a name for this logger's config; rarely needed! The log path is either /tmp or the value of the DISPATCHOULI_PATH env var. If the DISPATCHOULI_NOSYSLOG env var is true, we don't log to syslog. log $logger->log(@messages); $logger->log(\%arg, @messages); This method uses String::Flogger on the input, then logs the result. Each message is flogged individually, then joined with spaces. If the first argument is a hashref, it will be used as extra arguments to logging. It may include a "prefix" entry to preprocess the message by prepending a string (if the prefix is a string) or calling a subroutine to generate a new message (if the prefix is a coderef). log_fatal This behaves like the "log" method, but will throw the logged string as an exception after logging. This method can also be called as "fatal", to match other popular logging interfaces. If you want to override this method, you must override "log_fatal" and not "fatal". log_debug This behaves like the "log" method, but will only log (at the debug level) if the logger object has its debug property set to true. This method can also be called as "debug", to match other popular logging interfaces. If you want to override this method, you must override "log_debug" and not "debug". set_debug $logger->set_debug($bool); This sets the logger's debug property, which affects the behavior of "log_debug". get_debug This gets the logger's debug property, which affects the behavior of "log_debug". clear_debug This method does nothing, and is only useful for Log::Dispatchouli::Proxy objects. See Methods for Proxy Loggers, below. set_muted $logger->set_muted($bool); This sets the logger's muted property, which affects the behavior of "log". get_muted This gets the logger's muted property, which affects the behavior of "log". clear_muted This method does nothing, and is only useful for Log::Dispatchouli::Proxy objects. See Methods for Proxy Loggers, below. get_prefix my $prefix = $logger->get_prefix; This method returns the currently-set prefix for the logger, which may be a string or code reference or undef. See Logger Prefix. set_prefix $logger->set_prefix( $new_prefix ); This method changes the prefix. See Logger Prefix. clear_prefix This method clears any set logger prefix. (It can also be called as "unset_prefix", but this is deprecated. See Logger Prefix. ident This method returns the logger's ident. config_id This method returns the logger's configuration id, which defaults to its ident. This can be used to make two loggers equivalent in Log::Dispatchouli::Global so that trying to reinitialize with a new logger with the same "config_id" as the current logger will not throw an exception, and will simply do no thing. dispatcher This returns the underlying Log::Dispatch object. This is not the method you're looking for. Move along. LOGGER PREFIX
Log messages may be prepended with information to set context. This can be set at a logger level or per log item. The simplest example is: my $logger = Log::Dispatchouli->new( ... ); $logger->set_prefix("Batch 123: "); $logger->log("begun processing"); # ... $logger->log("finished processing"); The above will log something like: Batch 123: begun processing Batch 123: finished processing To pass a prefix per-message: $logger->log({ prefix => 'Sub-Item 234: ', 'error!' }) # Logs: Batch 123: Sub-Item 234: error! If the prefix is a string, it is prepended to each line of the message. If it is a coderef, it is called and passed the message to be logged. The return value is logged instead. Proxy loggers also have their own prefix settings, which accumulate. So: my $proxy = $logger->proxy({ proxy_prefix => 'Subsystem 12: ' }); $proxy->set_prefix('Page 9: '); $proxy->log({ prefix => 'Paragraph 6: ' }, 'Done.'); ...will log... Batch 123: Subsystem 12: Page 9: Paragraph 6: Done. METHODS FOR SUBCLASSING
string_flogger This method returns the thing on which flog will be called to format log messages. By default, it just returns "String::Flogger" env_prefix This method should return a string used as a prefix to find environment variables that affect the logger's behavior. For example, if this method returns "XYZZY" then when checking the environment for a default value for the "debug" parameter, Log::Dispatchouli will first check "XYZZY_DEBUG", then "DISPATCHOULI_DEBUG". By default, this method returns "()", which means no extra environment variable is checked. env_value my $value = $logger->env_value('DEBUG'); This method returns the value for the environment variable suffix given. For example, the example given, calling with "DEBUG" will check "DISPATCHOULI_DEBUG". METHODS FOR TESTING
new_tester my $logger = Log::Dispatchouli->new_tester( \%arg ); This returns a new logger that logs only "to_self". It's useful in testing. If no "ident" arg is provided, one will be generated. "log_pid" is off by default, but can be overridden. "\%arg" is optional. events This method returns the arrayref of events logged to an array in memory (in the logger). If the logger is not logging "to_self" this raises an exception. clear_events This method empties the current sequence of events logged into an array in memory. If the logger is not logging "to_self" this raises an exception. METHODS FOR PROXY LOGGERS
proxy my $proxy_logger = $logger->proxy( \%arg ); This method returns a new proxy logger -- an instance of Log::Dispatchouli::Proxy -- which will log through the given logger, but which may have some settings localized. %arg is optional. It may contain the following entries: proxy_prefix This is a prefix that will be applied to anything the proxy logger logs, and cannot be changed. debug This can be set to true or false to change the proxy's "am I in debug mode?" setting. It can be changed or cleared later on the proxy. parent logger These methods return the logger itself. (They're more useful when called on proxy loggers.) METHODS FOR API COMPATIBILITY
To provide compatibility with some other loggers, most specifically Log::Contextual, the following methods are provided. You should not use these methods without a good reason, and you should never subclass them. Instead, subclass the methods they call. is_debug This method calls "get_debug". is_info is_fatal These methods return true. info fatal debug These methods redispatch to "log", "log_fatal", and "log_debug" respectively. SEE ALSO
o Log::Dispatch o String::Flogger AUTHOR
Ricardo SIGNES <rjbs@cpan.org> COPYRIGHT AND LICENSE
This software is copyright (c) 2011 by Ricardo SIGNES. This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself. perl v5.10.1 2011-04-08 Log::Dispatchouli(3pm)