Readstring. Is it an error or just an empty string?

[Pud]

"Return value
Returns the read string, or an empty string if the read has failed."

What if your file contains empty strings how can you detect an error?

Cheers

[Saki]

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If FileSize(path$)<1 : Debug "Empty or not readable as File" : Endif

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If not LOF(file) : Debug "Empty" : endif

[BarryG]

That's not the answer, Saki. The text file could look like this:

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one
two
three

four

five

six
seven

Any of those blank lines will return an empty string with ReadString(), thus indicating an error.

[Pud]

Sorry my bad I didn’t mean just one string but a series of CR/LF delimited records.

[Saki]

Hi @Barry
Ah, if I understand correctly, then he must use the flag
#PB_File_IgnoreEOL.

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; As sample so :

string$=ReadString(file, #PB_File_IgnoreEOL|#PB_UTF8)

[NicTheQuick]

You can check if Loc(file) has changed after ReadString. If it has increased then you just read an empty string.

@Saki: Also you can not use #PB_Any with ReadString.

[Pud]

Saki, no ignore EOL is not a solution as I read many records separated with an EOL. See BarryG’s example above.

NicTheQuick. I’ll experiment with that one, cheers.

[Saki]

Hi Nick, yes that works not, an inadvertence...

[RASHAD]

I am not sure but it worth try

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If ReadFile(0, GetTemporaryDirectory()+"Test.txt")   ; if the file could be read, we continue...
    While Eof(0) = 0           ; loop as long the 'end of file' isn't reached
      Text$ = ReadString(0)      ; display line by line in the debug window
      Position.q = Loc(0)
      If Text$ = "" And Position = oldposition.q+2
        Debug "Empty Line"
      ElseIf Text$ = "" And Position > oldposition.q+2
        Debug "Line Error"
      EndIf 
      oldposition.q = Position.q
    Wend
    CloseFile(0)               ; close the previously opened file
  Else
    MessageRequester("Information","Couldn't open the file!")
  EndIf

[NicTheQuick]

I am not sure but it worth try

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If ReadFile(0, GetTemporaryDirectory()+"Test.txt")   ; if the file could be read, we continue...
    While Eof(0) = 0           ; loop as long the 'end of file' isn't reached
      Text$ = ReadString(0)      ; display line by line in the debug window
      Position.q = Loc(0)
      If Text$ = "" And Position = oldposition.q+2
        Debug "Empty Line"
      ElseIf Text$ = "" And Position > oldposition.q+2
        Debug "Line Error"
      EndIf 
      oldposition.q = Position.q
    Wend
    CloseFile(0)               ; close the previously opened file
  Else
    MessageRequester("Information","Couldn't open the file!")
  EndIf

Comparing with the old position +2 is not a good idea. If you have a plain ASCII file and Windows line endings (#CRLF$) this would work. But it does not work with UTF-16 files or with Linux line endings (#LF$) encoded as ASCII or UTF-8.

[RASHAD]

Sorry NicTheQuick
I did not read you previous post as I was busy listening to Irish Music

[Saki]

Hi @Pud

You can do it also with StringFields_BF, i think.
viewtopic.php?f=12&t=77219

The code for the small text file above then looks like this, multi OS

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Define index, separator$=#LF$
Define file=ReadFile(#PB_Any, "C:\Users\albus\OneDrive\Desktop\text.txt")
Define text$=ReadString(file, #PB_File_IgnoreEOL|#PB_UTF8)

If FindString(text$, #CR$) ; A part from DrawText_BF
  text$=ReplaceString(text$, #CRLF$, #LF$)
  text$=ReplaceString(text$, #LFCR$, #LF$)
  ReplaceString(text$, #CR$, #LF$, #PB_String_InPlace)
EndIf

Define mode=0
Debug "Mode : "+mode
StringFields_BF(text$, separator$, mode)
Debug "String length : "+Len(text$)
Debug "StringFields found : "+GetAmountStringFields_BF()
Debug "Empty StringFields found : "+GetEmptyStringFields_BF()

Debug "=============================="
For index=1 To GetAmountStringFields_BF()
  Debug GetStringFields_BF(index)
Next 

FreeAllStringFields_BF() ; Free the actual cached StringField list and init for a new function call

[Keya]

Saki btw what does BF stand for? been wondering for weeks lol

[Saki]

BF = Coders "Best Friend" - LOL

The Wizzard core code was once created from a BucketFill routine
which then became BucketFill_advanced and finally GFX_Wizzard_BF.
It was then kept to be able to assign the codes to a common source.