01-15-2009
Alright, so here is how error redirection works..
As you know, to send the STDOUT to /dev/null you do something like this: somecmd > /dev/null
So, to send STDERR to the same place, you can do:
somecmd 2> /dev/null
To send both STDOUT and STDERR to /dev/null you can do:
somecmd > /dev/null 2>&1
the 2 is writing to the same place that 1 is (which is dev null).. The &1 means "Whatever 1 is writing to".
Hopefully that explains it a bit better.
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LEARN ABOUT DEBIAN
poet::import
Poet::Import(3pm) User Contributed Perl Documentation Poet::Import(3pm)
NAME
Poet::Import -- Import Poet quick vars and utilities
SYNOPSIS
# In a script...
use Poet::Script qw($conf $poet $log :file);
# In a module...
use Poet qw($conf $poet $log :file);
DESCRIPTION
Poet makes it easy to import certain variables (known as "quick vars") and utility sets into any script or module in your environment.
In a script:
use Poet::Script qw(...);
and in a module:
use Poet qw(...);
where "..." contains one or more quick var names (e.g. $conf, $poet) and/or utility tags (e.g. ":file", ":web").
(Note that "use Poet::Script" is also necessary for initializing the environment, even if you don't care to import anything, whereas "use
Poet" has no effect other than importing.)
QUICK VARS
Here is the built-in list of quick vars you can import. Some of the variables are singletons, and some of them are specific to each package
they are imported into.
$poet
The global environment object, provided by Poet::Environment. This provides information such as the root directory and paths to
subdirectories.
For backward compatibility this is also available as $env.
$conf
The global configuration object, provided by Poet::Conf.
$cache
The cache for the current package, provided by Poet::Cache.
$log
The logger for the current package, provided by Poet::Log.
UTILITIES
Default utilities
The utilities in Poet::Util::Debug are always imported, with no tag necessary.
:file
This tag imports all the utilities in Poet::Util::File.
:web
This tag imports all the utilities in Poet::Util::Web. It is automatically included in all Mason components.
MASON COMPONENTS
Every Mason component automatically gets this on top:
use Poet qw($conf $poet :web);
"$m->cache" and "$m->log" will get you the cache and log objects for a particular Mason component.
CUSTOMIZING
Adding variables
To add your own variable, define a method called provide_var_varname in "MyApp::Import". For example to add a variable $dbh:
package MyApp::Import;
use Poet::Moose;
extends 'Poet::Import';
method provide_var_dbh ($caller) {
# Generate and return a dbh.
# $caller is the package importing the variable.
# $poet is the current Poet environment.
}
"provide_dbh" can return a single global value, or a dynamic value depending on $caller.
Now your scripts and libraries can do
use Poet::Script qw($dbh);
use Poet qw($dbh);
Adding utility tags
To add your own utility tag, define a class "MyApp::Util::Mytagname" that exports a set of functions via the ':all' tag. For example:
package MyApp::Util::Hash;
use Hash::Util qw(hash_seed all_keys);
use Hash::MoreUtils qw(slice slice_def slice_exists);
our @EXPORT_OK = qw(hash_seed all_keys slice slice_def slice_exists);
our %EXPORT_TAGS = ( 'all' => @EXPORT_OK );
1;
Now your scripts and libraries can do
use Poet::Script qw(:hash);
use Poet qw(:hash);
SEE ALSO
Poet
AUTHOR
Jonathan Swartz <swartz@pobox.com>
COPYRIGHT AND LICENSE
This software is copyright (c) 2012 by Jonathan Swartz.
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 v5.14.2 2012-06-05 Poet::Import(3pm)