User Guide

Ampex 1308911-02 6-3
DD-2 Utilities Manual Pages DD-2 Utilities Overview
The device special file can invoke default actions on open (such as rewinding the tape)
before the utility performs its operation. The device special file can also cause default
actions on close. In addition, the device special file configuration might affect other
characteristics of the interface, such as the logical data block size.
For detailed information on device special file options, see Appendix B.
6.2.3 Output Conventions
The Tape Management utilities have the following output conventions:
• Many utilities support the -stdout <output_spec> argument which specifies the output
stream written to stdout. Each output field in the string is identified by a unique keyword
[%field_name or %(field_name)] that you can specify to display the field, or omit to skip
the field.
• Some output fields consist of multi-element lists, in which each element is enclosed by
colons.
• All error and help messages are written to stderr; see “ERROR REPORTING” below.
• On success, all utilities return an exit status of zero. Utilities that support the
-stdout <output_spec> argument may also produce output to stdout.
• On failure, all utilities return a nonzero exit status (see “Exit Status” on page 6-5).
6.2.4 Arguments
The arguments supported by more than one utility are described below. For other arguments,
consult each utility’s manual page.
-help [
help_type ]
Displays help on stderr and invalidates all other options, cancelling any other actions. The
optional help_type specification indicates the kind of help to supply:
• stdout - lists the keywords that are valid for the-stdout <output_spec> argument.
• revision - displays the utility revision number.
• v_revision - displays the utility revision number, release date and time, and other
engineering information.
When -help is specified without the help_type argument, it displays the utility usage line.