Specifies an existing empty file that the output file is to be overlaid, or written to. The /OVERLAY qualifier is required when you use the /INDEXED_SEQUENTIAL qualifier. Format output-file-spec/OVERLAY
1 – Full Description
To specify that an empty file is to be overlaid with sorted records, use the /OVERLAY qualifier. If the input file organization is indexed-sequential, the output file must already exist and must be empty. If the output file is not empty, /OVERLAY does not write over the file. Instead, it appends the result of the sort to the existing output file. If the input file organization is sequential or relative, you can create an empty file for the sorted records using an OpenVMS RMS program and use the /OVERLAY qualifier to specify that the output file is to be overlaid. You can use the Create/FDL utility to create an empty data file; use the /OVERLAY qualifier to specify that Sort is to write output to that file. Any attributes that you specify when creating the empty file then become attributes of the Sort output file. See the OpenVMS Record Management Services Reference Manual for more information. You can also refer to this manual if you want to use the Convert utility to produce an indexed-sequential file on output.
2 – Example
$ CREATE/FDL=NEW.FDL AVERAGE.DAT $ SORT/KEY=(POS:1,SIZ:80) STATS.DAT AVERAGE.DAT/OVERLAY The FDL file NEW.FDL specifies special attributes for the file AVERAGE.DAT. When Sort writes output to that file, the resulting Sort output file has the attributes specified by the FDL file.