QB64-PE/internal/help/RUN.txt

'''RUN''' is a control flow statement that clears and restarts the program currently in memory or executes another specified program.

The multi-modular technique goes back to when QBasic and QuickBASIC had module size constraints. In QB64 it has been implemented so that that older code can still be compiled, though '''it is advisable to use single modules for a single project (not counting [[$INCLUDE]] libraries), for ease of sharing and also because the module size constraints no longer exist.'''



{{PageSyntax}}
:: '''RUN''' [{''line_number'' | ''filespec$''}] [''command_parameter(s)'']


{{Parameters}}
* ''line number'' specifies a line number in the main module code. 
* An optional ''filespec'' specifies a program to load into memory and run. 
: * BAS or EXE extensions are assumed to be the same as the calling module's extension, EXE or BAS (Qbasic only).
: * ''file names specs'' with other extensions must use the full filename. No extension requires a dot.
* In '''QB64''' ''command line parameters'' can follow the program file name and be read using the [[COMMAND$]] function later.


''Usage:''
* The starting [[line number]] MUST be one used in the main module code! Even with [[SUB]] or [[FUNCTION]] references. 
* If no line number is given the currently loaded program runs from the first executable line.
* In '''QB64''' RUN can open any kind of executable program and provide case sensitive program specific parameters. 
* RUN does not return to the calling procedure if the program called is not a Qbasic procedure!
* RUN closes all open files and closes the invoking program module before the called program starts. (Cannot use Basica's R) 
* If you do NOT want opened files to be closed use [[CHAIN]] instead.
* RUN should reset the [[RANDOMIZE]] sequence to the starting [[RND]] function value.(Not in QB64) 
* Note: Qbasic also allowed /RUN in a command line call to run a BAS file with the interpreter. QB64 cannot run BAS files!
* '''Note: RUN causes a stack leak in QB64 if it is called from within a [[SUB]] or [[FUNCTION]]. Avoid when possible!'''
* '''NOTE: [[Keywords_currently_not_supported_by_QB64#Keywords_Not_Supported_in_Linux_or_MAC_OSX_versions |Not available in Linux or Mac operating systems.]]'''


''QBasic/QuickBASIC:''
* In Qbasic '''/RUN''' can also be used to run a program module in a command line. Example: QB.EXE /L /RUN Module1.BAS


''Example 1:'' Shows how RUN can reference multiple line numbers in the main module code. No line number executes first code line.
{{CodeStart}} '' ''
PRINT " A", " B", " C", " D"
10 A = 1
20 B = 2
30 C = 3
40 D = 4
50 {{Cl|PRINT}} A, B, C, D
60 {{Cl|IF...THEN|IF}} A = 0 {{Cl|THEN}} 70 {{Cl|ELSE}} {{Cl|RUN}} 20    'RUN clears all values
70 {{Cl|IF...THEN|IF}} B = 0 {{Cl|THEN}} 80 {{Cl|ELSE}} {{Cl|RUN}} 30
80 {{Cl|IF...THEN|IF}} C = 0 {{Cl|THEN}} 90 {{Cl|ELSE}} {{Cl|RUN}} 40
90 {{Cl|IF...THEN|IF}} D = 0 {{Cl|THEN}} 100 {{Cl|ELSE}} {{Cl|RUN}} 50
100 {{Cl|PRINT}}
{{Cl|INPUT}} "Do you want to quit?(Y/N)", quit$
{{Cl|IF...THEN|IF}} {{Cl|UCASE$}}(quit$) = "Y" {{Cl|THEN}} {{Cl|END}} {{Cl|ELSE}} {{Cl|RUN}}  'RUN without line number executes at first code line
'' ''
{{CodeEnd}} 
{{OutputStart}}A       B       C       D
1       2       3       4
0       2       3       4
0       0       3       4
0       0       0       4
0       0       0       0

Do you want to quit?(Y/N)_
{{OutputEnd}}


''Example 2:'' Compile both programs below with QB64. ProgramA [[RUN]]s ProgramB with a parameter passed following the filename: 
{{CodeStart}} '            ================ ProgramA.BAS ===================
{{Cl|LOCATE}} 12, 36: {{Cl|PRINT}} "ProgramA"

{{Cl|LOCATE}} 23, 25: {{Cl|PRINT}} "Press any key to run ProgramB"
K$ = {{Cl|INPUT$}}(1)
{{Cl|RUN}} "ProgramB FS"  'pass FS parameter to ProgramB in QB64 ONLY

{{Cl|END}} '' ''
{{CodeEnd}}
: ''ProgramB'' checks for fullscreen parameter pass in QB64 and goes full screen. 
{{CodeStart}} '            ================ ProgramB.BAS ===================
{{Cl|LOCATE}} 12, 36: {{Cl|PRINT}} "ProgramB"
parameter$ = {{Cl|UCASE$}}({{Cl|COMMAND$}})
{{Cl|LOCATE}} 20, 33: {{Cl|PRINT}} "Parameter = " + parameter$
{{Cl|IF...THEN|IF}} {{Cl|LEFT$}}(parameter$, 2) = "FS" {{Cl|THEN}} {{Cl|_FULLSCREEN}} 'parameter changes to full screen

{{Cl|END}} '' ''
{{CodeEnd}}
{{OutputStart}}                              Parameter = FS.EXE
{{OutputEnd}}
: '''Note:''' The above RUN procedure will NOT work in Qbasic! Qbasic cannot pass [[COMMAND$]] parameters with RUN!


''See also:'' 
* [[CHAIN]], [[SHELL]]
* [[COMMAND$]]


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