Paul Evans > Error-Subclasses-0.05 > Error::SystemException

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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 ^

AUTHOR ^

Paul Evans <leonerd@leonerd.org.uk>

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