File i/o question.

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kip
Posts: 2
Joined: Apr 25, 2019 16:40

File i/o question.

Postby kip » May 23, 2019 18:32

What code will: Read 110-byte lines (50 bytes,50 bytes,10 bytes) from a text file
into 3 variables: a,b,c (diff. data-types), until a match is found?
MrSwiss
Posts: 3189
Joined: Jun 02, 2013 9:27
Location: Switzerland

Re: File i/o question.

Postby MrSwiss » May 23, 2019 18:45

First how exactly do you define a "match"? E.g. all three elements are of equal content?

In principle, there are no such "specific" language constructs in FB.
(unlike, e.g. VB.NET)

The way to deal with such "specifications", should be split into:
1) load everything (from file) to memory (for speed reasons)
2) split it into lines (searching for LF)
3) maybe its by now possible to compare file-line with comparison-line.
Otherwise, with differing data-types more splitting (see 2) is needed,
before a successful comparison is possible.

There is enough of code like that, already posted in this forum, why
don't you try a search ... (before asking, that is?).
Haubitze
Posts: 37
Joined: May 20, 2016 8:42

Re: File i/o question.

Postby Haubitze » May 24, 2019 0:06

read the complete line in a string and then split the string you get like this

Code: Select all

a=mid(in,1,50)
b=mid(in,51,50)
c=mid(in,101,10)

then you can convert all these strings to intergers or what else you will. see for that the 'string operations' in the FB-help.
dodicat
Posts: 5887
Joined: Jan 10, 2006 20:30
Location: Scotland

Re: File i/o question.

Postby dodicat » May 24, 2019 0:15

Or -- Load a text file into a udt array of ubyte arrays 50, 50, and 10
(Freebasic has a problem loading to a udt array of string fields, whether fixed length strings or fixed length zstrings)

When you have loaded the text file into the udt array of ubyte arrays then transfer the data to a udt of string fields.
The matching, I don't quite understand what you mean.

Code: Select all


#include "file.bi"

type arraytype
    as ubyte a(1 to 50)
    as ubyte b(1 to 50)
    as ubyte c(1 to 10)
end type

type stringtype
    as string a,b,c
end type

sub loadfiletoarray(file as string,b() as arraytype)
   If FileExists(file)=0 Then Print file;" not found":Sleep:end
   var  f=freefile
    Open file For Binary Access Read As #f
    If Lof(f) > 0 Then
      Get #f, , b()
    End If
    Close #f
end sub

Function loadfiletostring(file as string) as String
   If FileExists(file)=0 Then Print file;" not found":Sleep:end
   var  f=freefile
    Open file For Binary Access Read As #f
    Dim As String text
    If Lof(f) > 0 Then
      text = String(Lof(f), 0)
      Get #f, , text
    End If
    Close #f
    return text
end Function

Sub savefile(filename As String,p As String)
    Dim As Integer n
    n=Freefile
    If Open (filename For Binary Access Write As #n)=0 Then
        Put #n,,p
        Close
    Else
        Print "Unable to load " + filename
    End If
End Sub

'create a string of digits for example
dim as string * 10*110 g
for n as long=0 to len(g)-1
    g[n]=48+rnd*9
next


'save string to text file
savefile("text.txt",g)


'======================== work with text file ===========


var lngth=filelen("text.txt")\sizeof(arraytype) 'get load dimension

dim as arraytype a(1 to lngth)
dim as stringtype s(1 to lngth)

'must load into ubyte arraytype
loadfiletoarray("text.txt",a())

'transfer arraytype to stringtype
for n as long=1 to ubound(a)
   for m as long=1 to 50: s(n).a+= chr(a(n).a(m)):next
   for m as long=1 to 50: s(n).b+= chr(a(n).b(m)):next
   for m as long=1 to 10: s(n).c+= chr(a(n).c(m)):next
next

'now work with stringtype
print "stringtype array elements .a, .b, .c"
for n as long=1 to ubound(s)
    print s(n).a
    print s(n).b
    print s(n).c
       print
next

print


'check
print "Check"
dim as string acc
for n as long=1 to ubound(s)
    acc+=s(n).a+s(n).b+s(n).c
next
print

print "original text file"
dim as string L= loadfiletostring("text.txt")
print L
print "string from stringtype array"
print acc
print iif(acc=L,"OK","ERROR")
   
sleep
kill "text.txt"


 

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