On Mon, Feb 7, 2011 at 10:29 AM, Bec Carter <[email protected]> wrote:
> On Mon, Feb 7, 2011 at 10:25 AM, Noon Silk <[email protected]> wrote:
>> On Mon, Feb 7, 2011 at 10:21 AM, Bec Carter <[email protected]> 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.
--
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
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