2.3 Data Files

A data file is either stdin, one or more files, or both. If there is more than one source, they should all share a format that fits the specifications provided for output fields, fields holding numeric values to be summed, and fields to be used as keys for matching.

The following are the commands that specifically affect the processing of the data file. Some share the same name with options that can also apply to reference files. Those must be on your command line before you present your first reference file. The others could appear anywhere on the command line; however, convention dictates that all the data-file options should be together before the first reference file is named.

‘-w’

‘--write-output’

Signals the program that output records should be written every time a data record satisfies the matching criteria with the reference files. The record written will combine all specified output fields from the data file record, the matching reference file record(s), and any specified constant values. This option is a positional option for all files, and must appear before the first reference file is named.

‘-t filename’

‘--output-file=filename’

If provided, write the data-based output to filename. Otherwise the output will go to stdout. This option only makes sense if you plan to write data-file-based output. This is a positional option for all files and must appear before the first reference file is named.

‘-o range_string’

‘--output-fields=range_string’

Write the fields specified by range_string as part of the record in any data-based output. The range specifications share a common format with all field specifications for combine. This option only makes sense if you plan to write data-file-based output. This is a positional option and to apply to the data file it must appear before the first reference file is named.

‘-K string’

‘--output-constant=string’

Write string to the data-file-based output. This option only makes sense if you plan to write data-file-based output. This is a positional option and to apply to the data file it must appear before the first reference file is named.

‘-s range_string’

‘--sum-fields=range_string’

In any reference-file-based output write a sum of the value of the fields specified by range_string. The sum for a given reference file record will come from all data file records that matched it. This option only makes sense if you have requested reference-file-based output.

If a precision is provided for a sum field, that precision is honored, and decimal fractions up to that many digits will be included in the sum. Any further precision on the input fields will be ignored (without rounding) in the sum. The resulting sum will be written with a decimal point and the number of fractional digits implied by the precision.

This document was generated by Daniel P. Valentine on July 28, 2013 using texi2html 1.82.