On Mon, Feb 7, 2011 at 12:49 PM, Michael Minutillo
<michael.minuti...@gmail.com> wrote:
> If you're in .NET 4.0 land then I'd do something similar to this:
> public string ReplaceTokens(string src) { /* ... */ }
> File.WriteAllLines(outputFileName,
> File.ReadLines(inputFileName).Select(ReplaceTokens));
> The ReadLines call (new to .NET 4.0) reads one line at a time and returns it
> as you iterate over it so in theory you don't need to have the whole file in
> memory. Don't use the ReadAllLines method on a 750MB file which DOES read
> the whole thing in before you start.
>
>Cool I hadn't seen that in .NET 4.0. Cheers > > -- > Michael M. Minutillo > Indiscriminate Information Sponge > Blog: http://wolfbyte-net.blogspot.com > > > On Mon, Feb 7, 2011 at 7:58 AM, Grant Molloy <graken...@gmail.com> wrote: >> >> Bec, >> Read this article and download the demo.. >> It goes through several different options for "find and replace" in large >> text strings.. >> http://www.codeproject.com/KB/string/fastestcscaseinsstringrep.aspx >> Grant >> >> On Mon, Feb 7, 2011 at 9:43 AM, Bec Carter <bec.usern...@gmail.com> wrote: >>> >>> On Mon, Feb 7, 2011 at 10:35 AM, Noon Silk <noonsli...@gmail.com> wrote: >>> > On Mon, Feb 7, 2011 at 10:29 AM, Bec Carter <bec.usern...@gmail.com> >>> > wrote: >>> >> On Mon, Feb 7, 2011 at 10:25 AM, Noon Silk <noonsli...@gmail.com> >>> >> wrote: >>> >>> On Mon, Feb 7, 2011 at 10:21 AM, Bec Carter <bec.usern...@gmail.com> >>> >>> wrote: >>> >>>> Good mornin' all! >>> >>>> >>> >>>> I've a requirement to put certain values (after computing them) in >>> >>>> various spots in a very large text file. So basically the starting >>> >>>> text file can have placeholders where these computed values will end >>> >>>> up- like a template. Then my code will compute some values based on >>> >>>> user input and i need to fill in the placeholders. >>> >>>> >>> >>>> Is there a better way to do this besides a simple string replace? >>> >>> >>> >>> Well, no. You'll need to read the file in and find your tokens and >>> >>> replace them. Depending on how large the file it, you might need to >>> >>> do >>> >>> this line by line, or chunk by chunk, writing out as you read in, but >>> >>> inevitably it comes down to looking for a sequence and replacing it >>> >>> with another. >>> >>> >>> >>> How large is "very large"? Megs? Gigs? >>> >>> >>> >> >>> >> Yup reading all into a string right now and replacing. File is around >>> >> 750 megs >>> > >>> > Mm, in that case I would definitely think reading in chunk by chunk >>> > would be better. >>> > >>> > So, you read in chunks of chars in a char[], and then you must look >>> > for the start of your token. Taking care to note that you could end up >>> > in the middle of your token, something like: >>> > >>> > // Pseudocode >>> > char[] data = { "$te" } >>> > char[] nextData = { "st$" } >>> > >>> > Where the token is "$test$". >>> > >>> > Depending on your data, it might be that reading lines is enough, and >>> > do the replace on that basis. Hopefully this is somewhat clear. I had >>> > a quick search and couldn't find a nice example on doing this, but it >>> > should be easy enough using StreamReader or friends. If it's not clear >>> > I can show an example later on. >>> > >>> >>> That's fine thanks. Line by line would be ok as the data will never be >>> broken up and flow onto the next line. >>> >>> I was kinda hoping there'd be something specifically built for this- >>> seems like I'm creating mail merge all over again :-) >>> >>> > -- >>> > Noon Silk >>> > >>> > http://dnoondt.wordpress.com/ (Noon Silk) | >>> > http://www.mirios.com.au:8081 > >>> > >>> > Fancy a quantum lunch? >>> > http://www.mirios.com.au:8081/index.php?title=Quantum_Lunch >>> > >>> > "Every morning when I wake up, I experience an exquisite joy — the joy >>> > of being this signature." >>> > >> > >
