30 lines
821 B
Text
30 lines
821 B
Text
dim info$( 50, 50) ' NB pre-dimension before calling file-exists
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' needed for file-exists function
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open "test.dat" for output as #1 'create file
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for i = 1 to 10000
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#1 chr$( int( 256 *rnd( 1)));
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next
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close #1
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call truncateFile, "test.dat", 5000
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wait
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sub truncateFile fn$, length
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if fileExists( DefaultDir$, fn$) =0 then notice "No such file": exit sub
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open fn$ for input as #i
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file$ =input$( #i, lof( #i))
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if len( file$) <length then notice "Too short": close #i: exit sub
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file$ =left$( file$, length)
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close #i
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open "test.dat" for output as #o
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#o file$
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close #o
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end sub
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function fileExists( path$, filename$)
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files path$, filename$, info$()
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fileExists =val( info$( 0, 0)) 'non zero is true
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end function
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end
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