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6e01fc8dce
Added new _STRCMP and _STRICMP commands for quick string comparisons. Cleaned up QB64 to finish removing the QUI (quick user insert) code and folders. Altered UCASE and LCASE routines to be faster in some situations for us.
71 lines
2.6 KiB
Plaintext
71 lines
2.6 KiB
Plaintext
'''RANDOM''' is used in an [[OPEN]] statement to read([[GET]]) from or write([[PUT]]) to a file.
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{{PageSyntax}}
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:: OPEN Filename$ FOR RANDOM AS #1 [LEN = ''recordlength%'']
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* RANDOM is the Default mode if no mode is given in the OPEN statement.
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* It creates the file if the legal file name given does NOT exist.
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* As a RANDOM file, it can read or write any record using [[GET]] and/or [[PUT]] statements.
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* ''Recordlength%'' is determined by getting the LEN of a [[TYPE]] variable or a [[FIELD]] statement.
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* If no record length is used in the [[OPEN]] statement, the default record size is 128 bytes except for the last record.
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* A record length cannot exceed 32767 or an [[ERROR Codes|error]] will occur!
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* To determine the number of records in a file the records% = [[LOF]] \ recordlength%.
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* A serial communication port can also be opened for RANDOM in an [[OPEN COM]] statement.
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''Example:'' Function that finds a RANDOM file's record number for a string value such as a phone number.
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{{CodeStart}} '' ''
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{{Cl|TYPE}} customer
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age {{Cl|AS}} {{Cl|INTEGER}}
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phone {{Cl|AS}} {{Cl|STRING}} * 10
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{{Cl|END}} {{Cl|TYPE}}
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{{Cl|DIM}} {{Cl|SHARED}} cust {{Cl|AS}} customer, recLEN
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recLEN = {{Cl|LEN}}(cust) 'get the length of the record type
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{{Cl|PRINT}} "Rec{{Cl|LEN}}:"; recLEN
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{{Cl|OPEN}} "randfile.rec" {{Cl|FOR...NEXT|FOR}} {{Cl|RANDOM}} {{Cl|AS}} #1 {{Cl|LEN}} = recLEN
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{{Cl|FOR...NEXT|FOR}} i = 1 {{Cl|TO}} 4
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{{Cl|READ}} cust.age, cust.phone
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{{Cl|PUT}} #1, , cust
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{{Cl|NEXT}}
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{{Cl|CLOSE}} #1
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RP = RecordPos("randfile.rec", "2223456789") 'returns 0 if record not found!
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{{Cl|PRINT}} RP
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{{Cl|IF...THEN|IF}} RP {{Cl|THEN}}
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{{Cl|OPEN}} "randfile.rec" {{Cl|FOR...NEXT|FOR}} {{Cl|RANDOM}} {{Cl|AS}} #2 {{Cl|LEN}} = recLEN
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{{Cl|GET}} #2, RP, cust
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{{Cl|CLOSE}} #2
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{{Cl|PRINT}} cust.age, cust.phone
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{{Cl|END IF}}
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{{Cl|END}}
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{{Cl|DATA}} 59,2223456789,62,4122776477,32,3335551212,49,1234567890
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{{Cl|FUNCTION}} RecordPos (file$, search$)
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f = {{Cl|FREEFILE}}
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{{Cl|OPEN}} file$ {{Cl|FOR (file statement)|FOR}} {{Cl|INPUT (file mode)|INPUT}} {{Cl|AS}} #f
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FL = {{Cl|LOF}}(f)
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dat$ = {{Cl|INPUT$}}(FL, f)
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{{Cl|CLOSE}} f
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recpos = {{Cl|INSTR}}(dat$, search$)
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{{Cl|IF...THEN|IF}} recpos {{Cl|THEN}} RecordPos = recpos \ recLEN + 1 {{Cl|ELSE}} RecordPos = 0
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{{Cl|END FUNCTION}} '' ''
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{{CodeEnd}}
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:''Note:'' Random files can store records holding various variable types using a [[TYPE]] definition or a [[FIELD]] statement.
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''See also:''
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* [[GET]], [[PUT]], [[FIELD]]
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* [[BINARY]]
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* [[SEEK]], [[SEEK (statement)]]
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{{PageNavigation}} |