Difference between revisions of "LOC"

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The '''LOC''' function returns the status of a Serial(COM) port receive buffer or the current byte position in a file.
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The [[LOC]] function returns the status of a serial (COM) port received buffer or the current byte position in an open file.
 
 
  
  
 
{{PageSyntax}}
 
{{PageSyntax}}
:: bytes% = LOC(open_number)
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: {{Parameter|bytes%}} = LOC({{Parameter|fileOrPortNumber%}})
  
  
* The parameter used is the number used in the port [[OPEN]] AS statement.
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* {{Parameter|fileOrPortNumber%}} is the number used in the port [[OPEN]] AS statement.
* Returns 0 if the buffer is empty. Any value above 0 indicates COM has received data.
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* Returns 0 if the buffer is empty. Any value above 0 indicates the COM port has received data.
 
* Use it in conjunction with [[INPUT$]] to get the data bytes received.
 
* Use it in conjunction with [[INPUT$]] to get the data bytes received.
* Can also be used for the current position in a file routine. See: [[SEEK]]
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* Can also be used to read the current position in a file routine. See [[SEEK]].
  
  
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{{PageExamples}}
 
''Example:'' Reading and writing from a COM port opened in Basic.
 
''Example:'' Reading and writing from a COM port opened in Basic.
 
{{CodeStart}} '' ''
 
{{CodeStart}} '' ''
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''See also:''
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{{PageSeeAlso}}
 
* [[PRINT]], [[OPEN COM]], [[PRINT (file statement)]]
 
* [[PRINT]], [[OPEN COM]], [[PRINT (file statement)]]
 
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* [[SEEK]]
  
 
{{PageNavigation}}
 
{{PageNavigation}}

Latest revision as of 14:04, 9 October 2017

The LOC function returns the status of a serial (COM) port received buffer or the current byte position in an open file.


Syntax

bytes% = LOC(fileOrPortNumber%)


  • fileOrPortNumber% is the number used in the port OPEN AS statement.
  • Returns 0 if the buffer is empty. Any value above 0 indicates the COM port has received data.
  • Use it in conjunction with INPUT$ to get the data bytes received.
  • Can also be used to read the current position in a file routine. See SEEK.


Examples

Example: Reading and writing from a COM port opened in Basic.

OPEN "COM1: 9600,N,8,1,OP0" FOR RANDOM AS #1 LEN = 2048 ' random mode = input and output DO: t$ = INKEY$ ' get any transmit keypresses from user IF LEN(t$) THEN PRINT #1, t$ ' send keyboard byte to transmit buffer bytes% = LOC(1) ' bytes in buffer IF bytes% THEN ' check receive buffer for data" r$ = INPUT$(bytes%, 1) ' get bytes in the receive buffer PRINT r$; ' print byte strings consecutively to screen" END IF LOOP UNTIL t$ = CHR$(27) 'escape key exit CLOSE #


See also



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