The data_sink command provides the actual I/O redirection. It reads from standard input, i.e., from a pipe, and writes data to the sink file. Each data_sink instance will write only to its designated location in the sink file, based on the ID it is passed as a command line argument.

Hence data_sink is called with two arguments, the sink file name, and the sink ID, which is a number between 0 and nr_sinks - 1 inclusive. Its input will be provided through a pipe.

some_program | data_sink  -id ${id}  -sink_file data.sink

Subsequent calls to data_sink with the same ID will overwrite that sink's data. However, if the -append option is specified, the data will be appended, e.g.,

some_program | data_sink  -id ${id}  -append  -sink_file data.sink

Optionally, data_sink can produce feedback useful for tuning and/or debugging. The -verbose flag allows to set the level of information printed to standard error. For level 0 there is no feedback, level ` provides run time information, higher levels may be added in future.

Help on the avaible command line options for this command can be obtained using the -? flag.