Availability: All operators
Short options: ‘-O’, ‘-A’
Long options: ‘--ovr’, ‘--overwrite’, ‘--apn’, ‘--append’
If the output-file specified for a command is a pre-existing file,
then the operator will prompt the user whether to overwrite (erase) the
existing output-file, attempt to append to it, or abort the
operation.
However, interactive questions reduce productivity when processing large
amounts of data.
Therefore NCO also implements two ways to override its own safety
features, the ‘-O’ and ‘-A’ switches.
Specifying ‘-O’ tells the operator to overwrite any existing
output-file without prompting the user interactively.
Specifying ‘-A’ tells the operator to attempt to append to any
existing output-file without prompting the user interactively.
These switches are useful in batch environments because they suppress
interactive keyboard input.