NAME

Exception::System - The exception class for system or library calls

SYNOPSIS

  # Loaded automatically if used as Exception::Base's argument
  use Exception::Base,
    'Exception::System',
    'Exception::File' => {
        isa => 'Exception::System',
        has => 'file',
        stringify_attributes => [ 'message', 'errstr', 'file' ],
    };

  eval {
    my $file = "/notfound";
    open FILE, $file
        or Exception::File->throw(
               message=>"Can not open file",
               file=>$file,
           );
  };
  if ($@) {
    my $e = Exception::Base->catch;
    if ($e->isa('Exception::File')) { warn "File error:".$e->{errstr}; }
    if ($e->with(errname=>'ENOENT')) { warn "Caught not found error"; }
  }

DESCRIPTION

This class extends standard Exception::Base with handling system or library errors. The additional attributes of the exception object are filled on throw and contain the error message and error codes.

BASE CLASSES

• Exception::Base

CONSTANTS

ATTRS

Declaration of class attributes as reference to hash.

See Exception::Base for details.

ATTRIBUTES

Class attributes are implemented as values of blessed hash. The attributes of base class are inherited. See Exception::Base to see theirs description.

errstr (ro)

Contains the system error string fetched at exception throw. It is the part of the string representing the exception object. It is the same as $! variable in string context.

  eval { Exception::System->throw( message=>"Message" ) };
  my $e = Exception::Base->catch
    and print $e->errstr;

errstros (ro)

Contains the extended system error string fetched at exception throw. It is the same as $^E variable.

  eval { Exception::System->throw( message=>"Message" ); };
  if ($@) {
    my $e = Exception::Base->catch;
    if ($e->errstros ne $e->errstr) {
      print $e->errstros;
    }
  }

errno (ro)

Contains the system error number fetched at exception throw. It is the same as $! variable in numeric context. This attribute represents numeric value of the exception object in numeric context.

  use Errno ();
  eval { Exception::System->throw( message=>"Message" ); };
  if ($@) {
    my $e = Exception::Base->catch;
    if ($e->errno == &Errno::ENOENT) {  # explicity
      warn "Not found";
    }
    elsif ($e == &Errno::EPERM) {       # numeric context
      warn "Bad permissions";
    }
  }

errname (ro)

Contains the system error constant from the system error.h include file.

  eval { Exception::System->throw( message=>"Message" ); };
  my $e = Exception::Base->catch
    and $e->errname eq 'ENOENT'
    and $e->throw;

PRIVATE METHODS

_collect_system_data

Collect system data and fill the attributes of exception object. This method is called automatically if exception if throwed.

See Exception::Base.

SEE ALSO

Exception::Base.

BUGS

If you find the bug, please report it.

AUTHOR

Piotr Roszatycki <dexter@debian.org>

LICENSE

Copyright (C) 2007, 2008 by Piotr Roszatycki <dexter@debian.org>.

This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

See http://www.perl.com/perl/misc/Artistic.html