CommandLine$
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Description
- If you use parameters or switches in a command line statement, those parameters will be contained in the special variable CommandLine$. This is useful when running a .tkn file under the runtime engine. To check for the parameters, you inspect the CommandLine$ in your called program for the existence of any switches or parameters.
Usage
From the JB Help file, here is an example that will fill the background of a graphics window with the color "red" when opening. Notice how the CommandLine$ is inspected with the instr() function to see if it contains the parameter "red".
'commandlinetest1.bas ' 'program to be tokenized 'to commandlinetest1.tkn 'and used with runtime engine 'commandlinetest1.exe open "CommandLine$ Test" for graphics as #win print #win, "trapclose [quit]" 'convert to lower case for evaluation: CommandLine$ = lower$(CommandLine$) if instr(CommandLine$, "red") > 0 then print #win, "fill red; flush" end if wait [quit] close #win : end
Syntax
To call this program, you might use this syntax:
- run "commandlinetest1.tkn red"
or
- run "commandlinetest1.exe red"
Hints
- Multiple Parameters.Of course, your command line could contain more than one parameter. If so, you can use the WORD$() function to extract each word. For example:
if word$(CommandLine$, 1) = "red" then print #win, "fill red; flush" end if
- Parsing Numbers. The information in CommandLine$ can be anything that could be in a string. If you need to extract a number from the string, use the VAL() function:
first$ = word$(CommandLine$, 1) firstVal = val(first$)
- Suggestions for Use. From the Help file once again:
- The variable CommandLine$ could contain a filename which the program would open and load into a texteditor. The variable CommandLine$ could contain numbers to be used in calculations. As in the examples above, it could contain colors that determine the look of a window.
Useful Procedures
' Place a useful function using this keyword here