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Full Discussion: Indirect variables in Bash
Top Forums Shell Programming and Scripting Indirect variables in Bash Post 302769088 by DFr0st on Monday 11th of February 2013 06:50:46 AM
Old 02-11-2013
Indirect variables in Bash

Hello,
I've spent hours this morning reading various past forum posts and documentation pages but I can't find exactly what I need.

I'm trying to call a variable with a variable in the name without having to make a third variable.

For example:

Code:
path=AB
legAB=50

leg$path

I want to be able to call leg$path variable and get the value "50"


I am aware that if I created another variable I could do this using the ${! } notation:

Code:
var=leg$path
echo ${!var}=50

However, I want to be able to miss out this last step. Is this possible?
Thanks,
Dan

Last edited by DFr0st; 02-11-2013 at 08:05 AM..
 

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Tree::Simple::Visitor::FindByPath(3pm)			User Contributed Perl Documentation		    Tree::Simple::Visitor::FindByPath(3pm)

NAME
Tree::Simple::Visitor::FindByPath - A Visitor for finding an element in a Tree::Simple hierarchy with a path SYNOPSIS
use Tree::Simple::Visitor::FindByPath; # create a visitor object my $visitor = Tree::Simple::Visitor::FindByPath->new(); # set the search path for our tree $visitor->setSearchPath(qw(1 1.2 1.2.2)); # pass the visitor to a tree $tree->accept($visitor); # fetch the result, which will # be the Tree::Simple object that # we have found, or undefined my $result = $visitor->getResult() || die "No Tree found"; # our result's node value should match # the last element in our path print $result->getNodeValue(); # this should print 1.2.2 DESCRIPTION
Given a path and Tree::Simple hierarchy, this Visitor will attempt to find the node specified by the path. METHODS
new There are no arguments to the constructor the object will be in its default state. You can use the "setSearchPath" and "setNodeFilter" methods to customize its behavior. includeTrunk ($boolean) Based upon the value of $boolean, this will tell the visitor to include the trunk of the tree in the search as well. setSearchPath (@path) This is the path we will attempt to follow down the tree. We will do a stringified comparison of each element of the path and the current tree's node (or the value returned by the node filter if it is set). setNodeFilter ($filter_function) This method accepts a CODE reference as its $filter_function argument and throws an exception if it is not a code reference. This code reference is used to filter the tree nodes as they are collected. This can be used to customize output, or to gather specific information from a more complex tree node. The filter function should accept a single argument, which is the current Tree::Simple object. visit ($tree) This is the method that is used by Tree::Simple's "accept" method. It can also be used on its own, it requires the $tree argument to be a Tree::Simple object (or derived from a Tree::Simple object), and will throw and exception otherwise. getResult This method will return the tree found at the specified path (set by the "setSearchPath" method) or "undef" if no tree is found. getResults This method will return the tree's that make up the path specified in "setSearchPath". In the case of a failed search, this can be used to find the elements which did successfully match along the way. BUGS
None that I am aware of. Of course, if you find a bug, let me know, and I will be sure to fix it. CODE COVERAGE
See the CODE COVERAGE section in Tree::Simple::VisitorFactory for more inforamtion. SEE ALSO
These Visitor classes are all subclasses of Tree::Simple::Visitor, which can be found in the Tree::Simple module, you should refer to that module for more information. AUTHOR
stevan little, <stevan@iinteractive.com> COPYRIGHT AND LICENSE
Copyright 2004, 2005 by Infinity Interactive, Inc. <http://www.iinteractive.com> This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself. perl v5.10.1 2005-10-24 Tree::Simple::Visitor::FindByPath(3pm)
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