6.4 Types of Commands
Commands in pspp are divided roughly into six categories:
- Utility commands
- Set or display various global options that affect pspp operations.
May appear anywhere in a syntax file. See Utility commands.
- File definition commands
- Give instructions for reading data from text files or from special
binary “system files”. Most of these commands replace any previous
data or variables with new data or
variables. At least one file definition command must appear before the first command in any of
the categories below. See Data Input and Output.
- Input program commands
- Though rarely used, these provide tools for reading data files
in arbitrary textual or binary formats. See INPUT PROGRAM.
- Perform operations on data and write data to output files. Transformations
are not carried out until a procedure is executed.
- Restricted transformations
- Transformations that cannot appear in certain contexts. See Order of Commands, for details.
- Analyze data, writing results of analyses to the listing file. Cause
transformations specified earlier in the file to be performed. In a
more general sense, a procedure is any command that causes the
active dataset (the data) to be read.