How to read an entire file into a string variable?

Hi,
I'm just beginning to code with Blitz+ and, as my first project, I would like to open a MS Publisher file and extract some text out of it. Since I don't have the details of the .PUB file format, I plan to search within the file for a certain string which is always at the beginning of the text section I want to grab. For this, the INSTR command would be great, but:

1-How to put the entire file into a string variable without reading it byte by byte, which would be too slow
2- Is a 200K binary file too big to fit in a string?

Thnx in advance

You'd be better off loading the file into a bank.

Instead of reading the entire file into a single string you should read the file in a line at a time, using the same string variable every time, and check that line until you encounter the text you are looking for.

Or use a bank like GFK suggests. I should really learn how to use banks for data; I haven't done much file i/o other than ReadLine/WriteLine.

Is there a way to do a fast search on the content of a bank to retrieve a specific byte sequence? It needs to be fast since I have hundreds of these files, they are all about 180-200K in size. Only one file will be loaded at a time. That's why I was counting on INSTR to do the search. But, since the bank is in memory, that may be fast enough. I'll go do some more tests.

Try this:

Bank = LoadFileToBank("Filename.txt")
Result = FindTextInBank("some text",Bank)
If Result = 0
	Notify "String not found!"
Else
	Notify "Result found at offset " + Result
EndIf

Function LoadFileToBank(Filename$)
	FILE = ReadFile(Filename)
	BankID = CreateBank(FileSize(Filename))
	ReadBytes BankID,FILE,0,BankSize(BankID)
	CloseFile FILE
	Return BankID
End Function

Function FindTextInBank(Txt$,BankID,Start = 0)
	Ptr = Start
	Repeat
		T$ = Chr$(PeekByte(BankID,Ptr))
		If T$ = Left$(Txt$,1)
			For N = 1 To Len(Txt$)-1
				T$ = T$ + Chr$(PeekByte(BankID,Ptr+N))
				If T$ = Txt$ Then Exit
			Next	
		EndIf
		Ptr = Ptr + 1
	Until Ptr >= BankSize(BankID) Or T$ = Txt$
	If T$ = Txt$
		Return Ptr
	Else
		Return False
	EndIf
End Function

It works. Don't know how fast it is with big files though...

[EDIT] Just did a test on a 170k file - took ~4s to find a text string right near the end of the file.

I haven't really used banks before - there's probably a way of optimising this so that it works in a fraction of the time it currently takes.

[EDIT 2] Try it with debug off! Same test as above takes about 0.3s. :))

Here's a trick that just occurred to me.

WriteString writes an integer, the length of the string, followed by the string data.
ReadString reads this back into a Blitz string.

So you could use Blitz to build a new file consisting of an integer ( the length of the original file ) followed by the original file.

Then use ReadString on this new file.

Wow! Plenty of good ideas for me to work on...

At 0.3s, it will be more than fast enough. I may also try Floyd's idea in a slightly modified way: to overwrite the first 4 bytes in the file to make an integer that will be equal the length of the remaining bytes of the files and then read it as a string. That should work as I don't need those first 4 bytes anyway. I should work on a copy of a the file, though, which may slows down things a bit.

Thanks alot, guys.

You guys should check the codearchives...

http://www.blitzbasic.com/codearcs/codearcs.php?code=685

and

http://www.blitzbasic.com/codearcs/codearcs.php?code=687