NAME

Linux::Sysfs::Attribute - sysfs attributes

SYNOPSIS

    my $attr = Linux::Sysfs::Attributes->open($path);

    if ($attr->can_read) {
        $attr->read;
        printf "%s: %s\n", $attr->name, $attr->value;
    }

    if ($attr->can_write) {
        printf "Writing %s to %s at %s\n",
               $new_value, $attr->name, $attr->path;
        $attr->write($new_value);
    }

    $attr->close;

DESCRIPTION

A file in sysfs represents a device or driver attribute Attributes can be read only, write only, or read and write. File data can be ASCII and binary.

METHODS

open

    my $attr = Linux::Sysfs::Attribute->open($path);

Opens up a file in sysfs and creates a Linux::Sysfs::Attribute instance. File isn't read with this function. $path is the File/Attribute's path. Returns a Linux::Sysfs::Attribute object on success or undef on failure.

close

    $attr->close;

Cleans up and closes sysfs_attribute structure.

read

    $attr->read or die 'read failed';

Reads the supplied attribute. Since the maximum transfer from a sysfs attribute is a pagesize, function reads in up to a page from the file and stores it in Linux::Sysfs::Attribute object to be retrieved with $attr->value. Returns something true on success or something false on failure.

write

    $attr->write($value) or die 'write failed';

Writes to the supplied attribute. Function validates if the given attribute is writable, and writes the new value to the attribute. The user needs to supply the $value to be written. Returns something true on success or something false on failure.

value

    my $value = $attr->value;

Returns the value of the attribute. You need to call read() or write() first to use this method.

can_read

        my $can_read = $attr->can_read;

Returns something true if the attribute is readable, false otherwise.

can_write

        my $can_write = $attr->can_write;

Returns something true if the attribute is writable, false otherwise.

name

        my $name = $attr->name;

Returns the attributes name.

path

    my $path = $attr->path;

The path returned by this method represents the file/attribute's full path.

AUTHOR

Florian Ragwitz <rafl@debian.org>

COPYRIGHT & LICENSE

Copyright 2006 Florian Ragwitz, all rights reserved.

This library is free software; you can redistribute it and/or modify it under the terms of the GNU Library General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.

This library 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 Library General Public License for more details.

You should have received a copy of the GNU Library General Public License along with this library; if not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307 USA.