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That's the most useful web page I've ever created. It's kinda like that commercial that ends with the line "...but I did stay at a Holiday Inn Express last night." - you eagerly await an opportunity to use it. 
"Why don't you tie a kerosene-soaked rag around your ankles so the ants won't climb up and eat your candy ass..." - Dale Earnhardt, 1997
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"...the staggering layers of obscenity in your statement make it a work of art on so many levels." - Jason Jystad, 10/26/2001
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I Lol'ed out loud at work. Thank you for that. I feel like an idiot now because 15 people saw me burst into laughter.
You sir, get a well deserved 5.
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John john john
Brilliant! Thank you for that. Does that page have a licensing agreement or are we free to use it?
Seriously, if you plan to keep that running it could easily be my most frequently posted link here in the forums. 
led mike
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You are free to use/duplicate it. It's been available since about 1998, and right now, there's no plan to take it down.
"Why don't you tie a kerosene-soaked rag around your ankles so the ants won't climb up and eat your candy ass..." - Dale Earnhardt, 1997
-----
"...the staggering layers of obscenity in your statement make it a work of art on so many levels." - Jason Jystad, 10/26/2001
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Hi,
I've got a txt file I'm parsing and need to extract specific lines from it and copy them to another file. First I scanned the file for the lines of interest by using the readline function. Each time I got a line I'm interested in I inserted the line number into an array.In the end I got an array that holds the line numbers of the lines I'm interested in coping. Meaning, the start line in one cell and end line in another, and I've got several of those in the array.
How do I copy the block of lines (between 2 cells listed in the array )from one file to a new file? Do I need to sync the StreamReader of one file with the StreamWriter of the other? or are there any other better ideas as to how to do it? 
Thanks in advance,
Inbal
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Rather than only holding the line numbers in the array. Make it a string array*, and store the whole line in the array.
Then, once you've finished processing the initial file. Close it, and open up a stream to your new file. Now you can write each string value from the array into the new file.
(* Even better, Use a generic List<String> instead of an array. This will be strongly typed and automatically resize to hold however many lines you need)
Simon
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Simon Stevens wrote: Rather than only holding the line numbers in the array. Make it a string array*, and store the whole line in the array.
What happens when the file is very big (for the sake of argument 1GB)? I already thought about your solution, but it seems to me that it consume a lot of memory if I need to save the whole file into an array. If I want to focus only to copy the lines of interest which I know where they begin and where they end, how do I do it? any way to convert line numbers to file offset and use seek function get there?
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In that case, Have both the read and the write stream open at the same time. Every time you find a line you are interested in from the reader, write it directly to the write stream. This will prevent you from having more than one line in memory at any one time.
Simon
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Is there no way I can use line numbers to get to the specific line and start copying from there forth?
Inbal
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There is no method you can call to just jump to whatever line number in the file. Files do not have line numbers.
You're going to have to read the file, line-by-line, counting the number of lines you read, until you get to the point you want. You don't have to hold onto the lines you don't want in an array. Then start reading the file, line-by-line, and writing those lines out to whatever you want. Even now, you don't have to hold these lines in an array either.
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Hi
Why not writing the line to the new file ?? at the moment you decide to keep this line.
The array is not a very good solution because you need to parse the stream again
in order to go back and forward. (you need to keep the postion of the stream not the line No)
I think a good solution to your problem can be:
1.open the file
2.read line
3.if the line is to be saved -> process the line (if you need)
4.save the line in the output text file
5.read the next line.
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It could have been a good solution if I didn't mind the size of the output file. I have to know in advance if the block of lines I'm about to copy doesn't exceed 65000 lines per file. If it does than I need to split it into 2 consecutive files. That's why I scanned it in advance and saved the beginning and the end of the block in an array.
Inbal
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While you are writing a line to the output file
manage a counter that will be the limit size of the output file
when the counter as reach the limit
close the stream and open a new for a new file
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I recommend to you to do it on the fly, like other people is saying
The only thing you must be care about is to make the stream flush to prevent memory problems, i mean
void CopyLines(string inFile, string outFile){
StreamReader sr = new StreamReader(File.Open(inFile, FileMode.Open, FileAccess.Read, FileShare.ReadWrite));
StreamWriter sw = new StreamWriter(outFile);
string line;
while (!sr.EndOfStream) {
line = sr.ReadLine();
if ( Match(line) ) {
sw.WriteLine(line);
}
sw.Flush();
}
sr.Close();
sw.Close();
}
Maybe the Flush method should be not always called, i mean like if (i % 100 == 0) sw.Flush(), or use the AutoFlush property
Saludos!!
____Juan
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Now you're just taking the p!ss.
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tonyjsebastian1 wrote: How will you make .NET programs work in Linux ?
You've answered your own question:
tonyjsebastian1 wrote: mono
Yup...That's it...use mono.
tonyjsebastian1 wrote: what is mono????
Oh...hang on....I know the answer to this one.....
here[^]
Seriously, take a hint and, read this[^], and this[^], and this[^].
Don't know if you've noticed, but every time you post something it goes grey, this is because you are being an idiot. It's our subtle hint to you, if your post goes grey, it's a stupid post.
Simon
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thanks for complements
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I'm genuinely trying to help you. Read all the links I have given you. Learn how to use google first. Learn about forum etiquette, and learn how to ask smart questions. If you do this, you will get better answers to your questions. I've given you all the information you need to do this. No it is up to you to make use of the information and learn.
Simon
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hello Simon Stevens
i have never expected these words from people like u
" this is because you are being an idiot "
thanks a lot
Tony
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I'm only telling you the truth. You're never going to get answers to your questions if you keep asking them like you are. Learn from it and move on.
Simon
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What everyone is trying to say is that programming's main requirement is you have a strong ability to do research. Without it, your career ends shortly after it begins because you haven't kept up on the technology changes whizzing by. For instance, everything your'e asking right now is easily solved with about 5 minutes worth of work using Google and a little experimentation. If you're stuck using a TextBox, you dig around for documentation and examples on the TextBox. If you don't konw how to use a ToolTip control, you Google the documentation, examples, and create your own little projects to test what you think you know and what you suspect. This process NEVER ends in this business. If you can't teach yourself, you're in the wrong line of work.
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hello Simon Stevens
u realy hurt me i never forget this
i asked such questions bcz i am new in C# and not familiar with wht all C# have like u people knows
good bye
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I hope you are *actually* leaving and not just teasing us!!
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tonyjsebastian1 wrote: i asked such questions bcz i am new in C# and not familiar with wht all C# have like u people knows
Go to google, type in these keywords: .net linux
In general, for most of the answers in c#, go first to msdn website and search for what you are looking for. Microsoft has done such an awesome job in organizing the library and made it very easy to understand. If its not there, search in google.
I hope this helps you,
Prateek
p.s. I'm also a beginner, and believe me between msdn and google, most of my questions are answered.
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