jBC Run-time Options

Normally the debugger will try to display the line of source code associated with the current program position. The debugger will, by default, only look in the current working directory for the source file. You can use the -Jp option to give a list of file names to search in, each name delimited by a colon. The file can be any supported by jEDI, including hashed files and UNIX directories. The following example tells the debugger to lookfirst in the file BP in the home directory and then in the current working directory:
% prog -Jp$HOME/BP:.
You can also use the ‘p’ command from the debugger prompt to achieve the same effect.

• A new line character is printed.
• The maximum number of characters have been buffered.
• The program terminates, or calls another program through the PERFORM, EXECUTE, CHAIN or ENTER command.
• The program pauses due to execution of an INPUT, SLEEP or RQM statement.

For example, in the following code, the data is not actually printed until the very last line:
FOR Loop = 1 TO 10
   PRINT @(0,23):”Loop “:Loop:@(-4):
   CALL DOTHIS
NEXT Loop
PRINT “Completed”
Some legacy applications do this sort of thing, and the status message is not displayed when it is required. There are a number of ways to force each PRINT or CRT statement to be displayed:

• Use this -Ju option.
• Append a CHAR(0) to the end of the string. For example:
PRINT @(0,23):”Loop “:Loop:@(-4):CHAR(0):

Note that this incurs a performance penalty and should be avoided if possible. Small terminal populations will probably not see much degradation, but large terminal populations performing lots of screen based activity will incur a significant penalty.