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- FLOW CONTROL (BATCH BRANCHING) under CHOOSE
-
- The power of CHOOSE results from the ability to change the course of
- execution within batch streams via menu selections. DOS's "ERRORLEVEL"
- is used to effect branching within a batch file.
-
- Whenever a menu selection is made, CHOOSE sets the ERRORLEVEL as follows
- and exits to DOS.
-
- ERRORLEVEL=3 THIRD to LAST menu selection made
- ERRORLEVEL=2 SECOND to LAST menu selection made
- ERRORLEVEL=1 LAST menu selection made
- ERRORLEVEL=0 ESCAPE struck
-
- BATCH's "IF ERRORLEVEL=" sub-commands are used following each CHOOSE
- line to cause the appropriate branching in control flow as shown below.
-
- CHOOSE *** MAIN MENU ***^Windows^WordPerfect^Backup
- IF ERRORLEVEL=3 GOTO :WINDOWS
- IF ERRORLEVEL=2 GOTO :WORD_PROC
- IF ERRORLEVEL=1 GOTO :TAPE_BACKUP
- GOTO :ESC_STRUCK
-