HP 3000 Manuals HP 3000 Manuals
Input Files XSORT can input sequential MPE files, including files on non-disk devices such as tape. (Please see Section 7 for the commands required.) KSAM files may be input. Caution should be taken, however, because XSORT will skip deleted records. A deleted record has its first two bytes set to -1 (to hex "FFFF"). For Address-out sorts (SORTA), XSORT reads KSAM files in chronological sequence and determines record numbers accordingly. XSORT will normally assure that the first record for a KSAM file is record number 0. If you wish to start the Address-out numbering at 1, then you must supply the S Option spec with a "1" in column 7 or build the KSAM file with the Firstrec=1 option. (See Section 4 for further information regarding S Option specification.)
NOTE XSORT will not process IMAGE data base files.
The formal designator for a single-file sort is XSORTIN. For multiple-file sorts, formal file designators are XSORTIN1 through XSORTIN9. The multiple-file designators do not have to be continuous. You can skip file numbers, selecting XSORTIN1, XSORTIN7, and XSORTIN3, for example. However, you must start with XSORTIN1. When you use more than one input file: * You cannot do an Address-out (SORTA) sort. * You cannot do an in place sort, in which output file overlays input file. * XSORT bases its operations on the characteristics of the first file opened. All the other files are assumed to have the same, or compatible, characteristics (file type and record length). * You must be sure that all your specifications apply to all the records in all the files you wish to use in a multifile sort. * You can ensure that you do not accidentally do a single-file sort (instead of a multiple-file sort) by issuing the following MPE command prior to running your XSORT program: RESET XSORTIN (See "Use of the MPE RESET Command.") If single file input is from $STDIN, the specification records cannot be from $STDIN. They must be from a file referenced by the formal designator XSORTEXT.