The software product SDF (System Dialog Facility) supports the input of commands and program statements in interactive and batch mode as well as from procedures.
As can be seen from the product name “System Dialog Facility”, SDF supports the user primarily in the context of interactive input: for entry from the data display terminal, the user can choose any of three levels of guided dialog and two levels of unguided dialog.
The user may shift temporarily from unguided to guided dialog. If minimum or medium dialog guidance is used, temporary changeover to the next higher guidance level is possible.
Input from a procedure file and in batch mode is the same as in unguided dialog.
With inputs in batch mode, from a procedure file or in unguided dialog, an expression may be entered in place of a command or statement section. SDF replaces this entry with the contents of the specified job variable, the value of an S variable expression or a procedure parameter.
SDF protects sensitive entries such as passwords by blanking at the time of input and by masking them out in the log.
SDF checks entered commands and statements as well as their operand values for syntax errors. This includes a check whether, for instance, a specified operand value complies with the BS2000 naming conventions for files. If SDF detects a syntax error, it conducts a correction dialog with the user.
SDF also supports a dialog to rectify inputs which are formally correct but unacceptable in content (semantic errors). This is only possible if provision has been made for such a dialog in the command or statement implementation.
SDF saves syntactically correct inputs. The user can view the saved inputs or display a specific input again in order to reenter it unchanged or with modifications.
For interactive input, frequently used operand values which are not set as default values can be defined as task-specific defaults. Thereafter they need no longer be explicitly specified.
In conjunction with SDF-A (System Dialog Facility - Administration), SDF offers the possibility of influencing the functional scope of commands and statements by:
disabling commands and statements
restricting the function set, e.g. disabling operands or operand values
modifying commands or statements, e.g. changing the default value of an optional operand
defining user-specific commands upon whose entry a procedure is called (implemented procedure).
Modification of the command/statement set can be performed such that its effect is valid throughout the system or just for certain users.
Commands, statements, operands and operand values can be disabled either for all operating modes or only for a particular mode, e.g. interactive operation.
SDF is capable of supporting a multilingual command language.
SDF dialog guidance is performed in the language selected for the output of system messages. Prompts, help texts, SDF messages and comments in menus are displayed in this language.
The standard syntax files supplied to the customer contain these texts in German and English. Apart from that it is possible to translate the English command language keywords into another national language by renaming them in the syntax file (with the aid of SDF-A). The command CREATE-FILE, for example, could become the German ERZEUGE-DATEI.
SDF has its own BS2000 command language (commands in SDF format). This replaces the former command language (commands in ISP format), which was in use up to and including BS2000 V9.5A. Commands in ISP format are still supported by SDF for reasons of compatibility. However, SDF’s full functionality, e.g. user guidance, is available only when the new command language is used. Commands in SDF format are distinguished by being easy to read and to understand. They can be entered in highly abbreviated form.
The SDF-CONV utility routine enables the user to convert procedures which still contain ISP commands into procedures with the corresponding SDF commands (see the chapter“SDF-CONV”).