### 10.2 ADD FILES

         ADD FILES

         Per input file:
                 /FILE={*,'file_name'}
                 [/RENAME=(src_names=target_names)...]
                 [/IN=var_name]
                 [/SORT]

         Once per command:
                 [/BY var_list[({D|A})] [var_list[({D|A})]...]]
                 [/DROP=var_list]
                 [/KEEP=var_list]
                 [/FIRST=var_name]
                 [/LAST=var_name]
                 [/MAP]

`ADD FILES` adds cases from multiple input files. The output, which replaces the active dataset, consists all of the cases in all of the input files.

`ADD FILES` shares the bulk of its syntax with other pspp commands for combining multiple data files. See Combining Files Common Syntax, above, for an explanation of this common syntax.

When `BY` is not used, the output of `ADD FILES` consists of all the cases from the first input file specified, followed by all the cases from the second file specified, and so on. When `BY` is used, the output is additionally sorted on the `BY` variables.

When `ADD FILES` creates an output case, variables that are not part of the input file from which the case was drawn are set to the system-missing value for numeric variables or spaces for string variables.