NAME

Error::SystemException - an Error subclass to represent OS-thrown errors.

DESCRIPTION

This exception is used to indicate errors returned by the operating system, or underlying libraries. As well as a string error message, it also contains the string form of $! at the time the exception was thrown.

FUNCTIONS

$e = Error::SystemException->new( $message )

This function constructs a new exception object and returns it. Normally this function should not be necessary from most code, as it would be constructed during the Error->throw() method.

            

              
              
throw Error::SystemException( "Something went wrong" );
            
          

The value of $message is passed as the -text key to the superclass constructor, and the numerical value of $! at the time the exception object is built is passed as the -value key. The string value of $! is also stored in the object.

$str = $self->perror

This function returns the stored string value of Perl's $! variable at the time the exception object was created.

EXAMPLES

Typically, this exception class would be used following the failure of a system call.

            

              
              
mkdir( $dir ) or throw Error::SystemException( "Cannot mkdir( '$dir' )" );
            
          

If caught, this exception would print a message perhaps looking like

            

              
              
Cannot mkdir( '/root/testdir' ) - Permission denied
            
          

Because it is a subclass of Error, the usual try/catch mechanisms also apply to it.

            

              
              
try {
    mkdir( $dir ) 
        or throw Error::SystemException( "mkdir($dir)" );
    try {
        chmod( $mode, $dir )
            or throw Error::SystemException( "chmod($dir)" );
        chown( $uid, $gid, $dir )
            or throw Error::SystemException( "chown($dir)" );
    }
    catch Error with {
        my $e = shift;
        rmdir( $dir );
        $e->throw;
    };
}
catch Error with {
    my $e = shift;
    # handle $e here...
};
            
          

SEE ALSO

• Error - Base module for exception-based error handling

AUTHOR

Paul Evans <leonerd@leonerd.org.uk>