---
name: "Config::Model::Backend::ShellVar"
section: "3pm"
platform: "linux"
package: "libconfig-model-perl"
version: "2.155-1"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/Config::Model::Backend::ShellVar"
---

# Config::Model::Backend::ShellVar(3pm)

Read and write config as a "SHELLVAR" data structure

## NAME

Config::Model::Backend::ShellVar - Read and write config as a "SHELLVAR" data structure

## VERSION

version 2.155

## SYNOPSIS

```
 use Config::Model;
 my $model = Config::Model->new;
 $model->create_config_class (
    name    => "MyClass",
    element => [
        [qw/foo bar/] => {qw/type leaf value_type string/}
    ],
   rw_config  => {
     backend => 'ShellVar',
     config_dir => '/tmp',
     file  => 'foo.conf',
     auto_create => 1,
   }
 );
 my $inst = $model->instance(root_class_name => 'MyClass' );
 my $root = $inst->config_root ;
 $root->load('foo=FOO1 bar=BAR1' );
 $inst->write_back ;
```

File `"foo.conf"` now contains:

```
 ## This file was written by Config::Model
 ## You may modify the content of this file. Configuration
 ## modifications will be preserved. Modifications in
 ## comments may be mangled.
 ##
 foo="FOO1"
 bar="BAR1"
```

## DESCRIPTION

This module is used directly by Config::Model to read or write the content of a configuration tree written with `"SHELLVAR"` syntax in `"Config::Model"` configuration tree.

Note that undefined values are skipped for list element. I.e. if a list element contains `"('a',undef,'b')"`, the data structure contains `'a','b'`.

## CONSTRUCTOR

### new

Parameters: `"( node => $node_obj, name => 'shellvar' )"`

Inherited from Config::Model::Backend::Any. The constructor is called by Config::Model::BackendMgr.

### read

Of all parameters passed to this read call-back, only `"file_path"` is used.

When a file is read, `"read"` returns 1.

### write

Of all parameters passed to this write call-back, only `"file_path"` is used.

`"write"` returns 1.

## AUTHOR

Dominique Dumont, (ddumont at cpan dot org)

## SEE ALSO

Config::Model,  Config::Model::BackendMgr,  Config::Model::Backend::Any,

## AUTHOR

Dominique Dumont

## COPYRIGHT AND LICENSE

This software is Copyright (c) 2005-2022 by Dominique Dumont.

This is free software, licensed under:

```
  The GNU Lesser General Public License, Version 2.1, February 1999
```