Quickly read last line in text file

Keywords: Binary read last line file

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Question:

One DOS application creates a report and saves it to a disk file. I want to read that file and take the TOTAL which is at the end of the report. If I read the file with "FileRead", I have to read record by record until the last record, but that takes to much time because the report is big (2 MB).

Can you tell me another method to reach the end of file without reading the file record by record?

Answer:

I think the binary operations will give you the speed you are looking for.

The code would look something like this....

file="C:\Temp\abc.txt" 
fsize=FileSize(file)
buffer=BinaryAlloc(fsize)
;read file into binary buffer
BinaryRead(buffer,file)
endoffile=BinaryEODGet(buffer)-1
While 1
   ;locate lines by getting pointers to @CRLFS
   beginptr=BinaryIndexEx(buffer,endoffile,@CRLF,@BACKSCAN,0)
   if beginptr != '-1'
   endptr=endoffile-beginptr+1
        lastline=BinaryPeekStr(buffer,beginptr,endptr)
        if lastline=="" || lastline==@CRLF
           endoffile=endoffile-2
    continue
        endif
        ;trim @CLRF off string
        lastline=strReplace(lastline,@CRLF,'')
   message("Last Line",lastline)
        break
else
   message("CRLF Not Found"," Not a valid ascii file.") 
   break
endif
endwhile
BinaryFree(buffer)
message("Last line retriever","Done")



       

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Article ID:   W14711

Filename:   Quickly read last line in text file.txt