NAME

Config::PFiles::Path - manipulate PFILES path for IRAF Compatible parameter files

SYNOPSIS

    use Config::PFiles::Path;

    $path = Config::PFiles::Path->new( \%options);

    # append to writeable or readonly directories
    $path->append( RW => @dirs );
    $path->append( RO => @dirs );

    # prepend to writeable or readonly directories
    $path->prepend( RW => @dirs );
    $path->prepend( RO => @dirs );

    # extract directories
    @rw_dirs = $path->extract( 'RW' );
    @ro_dirs = $path->extract( 'RO' );

    # replace writeable or readonly directories
    @rw_dirs = $path->replace( RW => @dirs );
    @ro_dirs = $path->replace( RW => @dirs );

    # remove writeable or readonly directories
    @rw_dirs = $path->remove( 'RW' );
    @ro_dirs = $path->remove( 'RO' );

    # create a sring version of the path
    $pfiles = $path->export;

    # work directly on $ENV{PFILES}
    Config::PFiles::Path->append( RO => @dirs );

DESCRIPTION

Config::PFiles::Path manipulates the parameter file path used by IRAF "compatible" parameter interfaces (IRAF (of course), CIAO's cxcparam, MARX's libpfile, INTEGRAL's PIL). The path is composed of two sets of directories; the first is both user readable and user writeable, the other is only user readable. The path is kept in the PFILES environmental variable, and takes the form

  rw1:rw2;ro1:ro2

where directories to the left of the semicolon are user readable and writeable and those to the right are readable only.

INTERFACE

Config::PFiles::Path can operate directly upon $ENV{PFILES} or can operate on a path object which can be exported.

There are two approaches to operating directly on $ENV{PFILES}.

Use class methods
If the methods in Config::PFiles::Path are used as class (rather than object) methods, they work directly upon $ENV{PFILES}. For example,
```
    Config::PFiles::Path->prepend( RW => "$ENV{HOME}/pfiles" );
```
Specify the method and its parameters on package loading
Methods which change the path ( append, prepend, remove, and replace) may be specified when the package is loaded:
```
    use Config::PFiles::Path prepend => RW => "$ENV{HOME}/pfiles";
```
Note that the method name is passed as a string; this example uses the => operator to quote things. The above may also have been written as
```
    use Config::PFiles::Path ('prepend', 'RW', "$ENV{HOME}/pfiles");
```
This approach lends itself to situations where only a single manipulation is required.

Object methods don't touch $ENV{PFILES}. For example,

    $env = Config::PFiles::Path->new( $ENV{PFILES} );
    $env->prepend( RW => "$ENV{HOME}/pfiles" );

modifies the path object $env.

Methods

new

  $path = Config::PFiles::Path->new( $pfiles );

This creates a new Config::PFiles::Path object using the provided parameter file path. Typically this will be $ENV{PFILES}. If $pfiles is not specified an empty path is constructed.

export

  $PFILES = $path->export;

This method generates a string version of the current path. See also "Overloaded Operators".

append

  $path->append( RW => @dirs );
  $path->append( RO => @dirs );

Append a list of directories to either the read/write set or read-only set of directories. The first argument indicates the set to append to.

prepend

  $path->prepend( RW => @dirs );
  $path->prepend( RO => @dirs );

Prepend a list of directories to either the read/write set or read-only set of directories. The first argument indicates the set to prepend to.

replace

  @old_rw_dirs = $path->replace( RW => @dirs );
  @old_ro_dirs = $path->replace( RO => @dirs );

Replace either the read/write set or read-only set of directories. The first argument indicates the set to replace.

remove

  @rw_dirs = $path->remove( 'RW' );
  @ro_dirs = $path->remove( 'RO' );

Delete either the read/write set or read-only set of directories. The set of deleted directories is returned. The first argument indicates the set to delete.

extract

  @rw_dirs = $path->extract( 'RW' );
  @ro_dirs = $path->extract( 'RO' );

Extract either the read/write set or read-only set of directories. The first argument indicates the set to extract.

Overloaded Operators

Config::PFiles::Path overloads the "" operator. When interpolating an object in a string it will be replaced with the output of the export() method.

BUGS AND LIMITATIONS

No bugs have been reported.

Please report any bugs or feature requests to bug-config-pfiles-path@rt.cpan.org, or through the web interface at http://rt.cpan.org/NoAuth/ReportBug.html?Queue=Config-PFiles-Path.

VERSION

Version 0.02

LICENSE AND COPYRIGHT

Config::PFiles::Path is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program. If not, see <http://www.gnu.org/licenses/>.

AUTHOR

Diab Jerius <djerius@cpan.org>