Log::Agent::Channel::File(3) file logging channel for Log::Agent


require Log::Agent::Channel::File;
my $driver = Log::Agent::Channel::File->make(
-prefix => "prefix",
-stampfmt => "own",
-showpid => 1,
-magic_open => 0,
-filename => "/tmp/output.err",
-fileperm => 0640,
-share => 1,


The file channel performs logging to a file, along with the necessary prefixing and stamping of the messages.

Internally, the "Log::Agent::Driver::File" driver creates such objects for each logging channel defined at driver creation time.

The creation routine make() takes the following arguments:

"-filename" => file
The file name where output should go. The file is opened in append mode and autoflushing is turned on. See also the "-magic_open" flag.
"-fileperm" => perm
The permissions that the file should be opened with (XOR'd with the user's umask). Due to the nature of the underlying open() and sysopen(), the value is limited to less than or equal to 0666. See ``umask'' in perlfunc(3) for more details.
"-magic_open" => flag
When true, channel filenames beginning with '>' or '|' are opened using Perl's open(). Otherwise, sysopen() is used, in append mode.

Default is false.

"-no_newline" => flag
When set to true, never append any ``\n'' (on Unix) or ``\r\n'' (on Windows) to log messages.

Internally, Log::Agent relies on the channel to delimit logged lines appropriately, so this flag is not used. However, it might be useful for "Log::Agent::Logger" users.

Default is false, meaning newline markers are systematically appended.

"-no_prefixing" => flag
When set to true, disable the prefixing logic entirely, i.e. the following options are ignored completely: "-prefix", "-showpid", "-no_ucfirst", "-stampfmt".

Default is false.

"-no_ucfirst" => flag
When set to true, don't upper-case the first letter of the log message entry when there's no prefix inserted before the logged line. When there is a prefix, a ``:'' character follows, and therefore the leading letter of the message should not be upper-cased anyway.

Default is false, meaning uppercasing is performed.

"-prefix" => prefix
The application prefix string to prepend to messages.
"-rotate" => object
This sets a default logfile rotation policy. You need to install the additional "Log::Agent::Rotate" module to use this switch.

object is the "Log::Agent::Rotate" instance describing the rotating policy for the channel. Only files which are not opened via a so-called magic open can be rotated.

"-share" => flag
When true, this flag records the channel in a global pool indexed by filenames. An existing file handle for the same filename may be then be shared amongst several file channels.

However, you will get this message in the file

 Rotation for 'filename' may be wrong (shared with distinct policies)

when a rotation policy different from the one used during the initial opening is given. Which policy will be used is unspecified, on purpose.

"-showpid" => flag
If set to true, the PID of the process will be appended within square brackets after the prefix, to all messages.

Default is false.

"-stampfmt" => (name | CODE)
Specifies the time stamp format to use. By default, my ``own'' format is used. See Log::Agent::Stamping for a description of the available format names.

You may also specify a CODE ref: that routine will be called every time we need to compute a time stamp. It should not expect any parameter, and should return a string.


Beware of chdir(). If your program uses chdir(), you should always specify logfiles by using absolute paths, otherwise you run the risk of having your relative paths become invalid: there is no anchoring done at the time you specify them. This is especially true when configured for rotation, since the logfiles are recreated as needed and you might end up with many logfiles scattered throughout all the directories you chdir()ed to.


Originally written by Raphael Manfredi <[email protected]>, currently maintained by Mark Rogaski <[email protected]>.


Copyright (C) 1999 Raphael Manfredi. Copyright (C) 2002 Mark Rogaski, [email protected]; all rights reserved.

See Log::Agent(3) or the README file included with the distribution for license information.