1Agent::Channel(3) User Contributed Perl Documentation Agent::Channel(3)
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6 Log::Agent::Channel - ancestor class for all Log::Agent channels
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9 @Log::Agent::Channel::XXX::ISA = qw(Log::Agent::Channel);
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12 The "Log::Agent::Channel" class is the root class from which all
13 "Log::Agent" channels inherit. It is a deferred class, meaning that it
14 cannot be instantiated directly. All the deferred routines need to be
15 implemented by its heirs to form a valid driver.
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17 Internally, the various "Log::Agent::Driver" objects create
18 "Log::Agent::Channel" instances for each logging channel defined at
19 driver creation time. The channels are therefore architecturally
20 hidden within "Log::Agent", since this module only provides redefined
21 mappings for the various logxxx() routines (logerr(), logwarn(),
22 logdie(), etc...).
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24 However, this does not mean that channel classes cannot be used
25 externally: the "Log::Agent::Logger" extension makes
26 "Log::Agent::Channel" objects architecturally visible, thereby offering
27 an application-level logging API that can be redirected to various
28 places transparently for the application.
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31 The following channels are currently made available by "Log::Agent".
32 More channels can be defined by the "Log::Agent::Logger" extension:
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34 Log::Agent::Channel::File
35 This channel writes logs to files, defined by their path or via a
36 magical opening sequence such as "|cmd". See
37 Log::Agent::Channel::File.
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39 Log::Agent::Channel::Handle
40 This channel writes logs to an already opened descriptor, as
41 specified by its file handle: an IO::Handle object, or a GLOB
42 reference such as \*FILE. See Log::Agent::Channel::Handle.
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44 Log::Agent::Channel::Syslog
45 This channel redirects logs to the syslogd(8) daemon, which will
46 then handle the dispatching to various logfiles, based on its own
47 configuration. See Log::Agent::Channel::Syslog.
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50 You need not read this section if you're only using "Log::Agent".
51 However, if you wish to implement another channel, then this section
52 might be of interest.
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54 The following routines are deferred and therefore need to be defined by
55 the heir:
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57 write($priority, $logstring)
58 Emit the log entry held in $logstring, at priority $priority. A
59 trailing "\n" is added to the $logstring, if needed (i.e. if the
60 physical entity does not do it already, like syslog does).
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62 The $priority argument must be a valid syslog priority, i.e. one of
63 the following strings: "emerg", "alert", "crit", "err", "warning",
64 "notice", "info", "debug".
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66 The $logstring may not really be a plain string. It can actually be
67 a Log::Agent::Message object with an overloaded stringification
68 routine, so the illusion should be complete.
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70 close
71 Close the channel.
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73 make
74 This is the creation routine. Its signature varies for each
75 channel, naturally.
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78 Raphael Manfredi <Raphael_Manfredi@pobox.com>
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81 Log::Agent::Channel::File(3), Log::Agent::Channel::Handle(3),
82 Log::Agent::Channel::Syslog(3), Log::Agent::Logger(3).
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86perl v5.28.0 2017-10-27 Agent::Channel(3)