Redirects the output of diagnostic messages from stderr to the specified errors file.
is the name of the file to which errors are to be redirected.
Diagnostics that relate to problems with the command options are not redirected, for example, if you type an option name incorrectly. However, if you specify an invalid argument to an option, for example --cpu=999, the related diagnostic is redirected to the specified filename .
This option is useful on systems where output redirection of files is not well supported.