An output Dictionary is used to describe the output binary data. It also contains the processing history accumulated for the dataset. Outputting a Dictionary is normally done thru the "out" alias name by any of these ways:

out= dictionay
out=tmpxxx:
out=/dev/null
out=/dev/null/rst0b
out=stdout:

The processing history is updated and written to this Dictionary. It contains any processing history possibly from an input Dictionary along with all the current processing information and Definitions introduced by this step.

The "tmpxxx:" mnemonic creates a temporary disk file that is automatically removed. Using "/dev/null" simply thows away the Dictionary. Both of these can be used for "out_data" as well.

The output data can be written directly to a tape device by specifying its "device name" such as "/dev/rst0b" (see Devices for more detail). This can be used for "out_data" as well.

The output data can also be sent to a pipe by specifying "stdout:". This can be used for "out_data" as well.

Most applications will default the output format to the format of the input dataset. In some cases the default output format may be hard coded to "fcube" or some other format. The end user may choose to override the default format for the binary output binary. Perhaps the next processing step requires a different format. Using the "out" alias name the output format can be overridden by:

out_format= format ...

DDS will determine a default for the full output binary pathname (see Binary Data). The end user may choose to override the filename for the binary output data. It may be on another file system that provides speed, capacity, or special backup. For example:

out_data= binary_name

Attaching Binary to the Dictionary:

By specifying the output binary data to be "dict:" the binary data will be attached to the end of the dictionary. This keeps the dataset all in a single file. This can be beneficial for archiving purposes. It also allows both Dictionary and binary data to be piped together to other DDS applications.

out_data=dict:

If the output Dictionary is not a regular file (i.e. pipe, tape, ...) then the binary data is automatically attached to the output Dictionary so that the dictionary information and binary data share the same file, pipe stream, or tape media.

Output Standard Format Binary:

When outputting data in any Standard Format (usp, segy, segy1, su) the Dictionary is optional. So if the output Dictionary is not needed, specify "out=/dev/null" or, better, simply specify data and format without a Dictionary output. This will result in only creating the binary. For example:

out_format=usp
out_data=line2.usp
    

Piping:

Shell operators (">" and "|") may be used to redirect output, when "out= stdout:". Many applications default the output to "stdout:". This default is ignored, if standard output is connected to a terminal. It's also ignored, if "par:" defines "out_data". This allows "stdout:" to be used for binary only data, when piping into a non-DDS application.

When piping usp binary data, the values are kept in the host-dependent formats -- Little Endian for Linux. This is to keep compatability with USP applications. NOTE: USP cannot be piped across different platform types.