try command-or-block catch [[local|my] $variable] command-or-block

Execute the command-or-block following the try keyword. If an error or exception occurs during the evaluation, execute the catch command-or-block. If the catch keyword is followed by a variable (possibly localized for the following block using my or local) and the try block fails with an exception, the error message of the exception is stored to the variable before the catch block is executed.

The throw command as well as an equivalent Perl construction perl { die "error message" } allow user to throw custom exceptions.

Unless exception is raised or error occurs, this command returns the return value of the try block; otherwise it returns the return value of the catch block.

try {
  $doc:=open --format xml $input;
} catch {
  try {
    echo "XML parser failed, trying HTML";
    $doc := open --format html $input;
  } catch my $error {
    echo "Stopping due to errors: $error";
    exit 1;
  }
}

throw