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Hi all,
I am having a little trouble with Regex.
Basically i have a text file that i am trying to parse.
In this file i know there will be a number of names, these names will always use 100 bytes of space, if the name, in plain ASCII code, is less then 100 bytes the remainder of the space is filed with 0xFF
My regex code is as follows.
streamreader sr = new streamreader("file.txt");
string text = sr.ReadToEnd();
sr.close();
string pattern = @"[A-Za-z0-9]|\xFF{100}";
Regex = new Regex(pattern);
foreach(Match match in Regex.Matches(text))
{
}
I think the problem is with the \xFF part of the program, as a simple regex expression such as @"\xFF" returns no where near as many 0xFF values as are present in the file
Thanks for any help
If only MySelf.Visible was more than just a getter...
A person can produce over 5 times there own body weight in excrement each year... please re-read your questions before posting
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How about something like:
@"[A-Za-z0-9\xFF]{100}";
(Untested)
And about whitespace?
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thanks for your reply,
I have tried your suggestion too and get the same results. white space characters in addition to basic symbols may be present but for now im just looking to get this one working as i am certain the HEX value is what is causing me problems
If only MySelf.Visible was more than just a getter...
A person can produce over 5 times there own body weight in excrement each year... please re-read your questions before posting
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Hi,
ReadToEnd reads data as text, i.e. it applies an encoding to interpret the bytes and returns a Unicode string. Are you sure your text still holds characters with the value \u00FF?
I suggest you print out a few hundred chars in hex and check.
Luc Pattyn [Forum Guidelines] [My Articles]
- before you ask a question here, search CodeProject, then Google
- the quality and detail of your question reflects on the effectiveness of the help you are likely to get
- use the code block button (PRE tags) to preserve formatting when showing multi-line code snippets
modified on Sunday, June 12, 2011 8:43 AM
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Oh, yeah, I hadn't thought of that.
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Thanks Luc, correct as allways
Printed the chars out as ints and found they where much higher than i was expecting. the thing i found unusual thou, atleats in my opinion, was that FF became 65333 as did a number of other Hex values over D8 (maybe lower values but i didnt see any others)
is there any reason why FF should not translate to 00FF?
Anyway my resulting modification was to loop the BaseStream and use a string builder with each byte read. works just as i expect now
While on the subject. Do you know if it is possible to perform a Regex search on the file itself?
i understand that a full string is required to ensure patterns are not split but it just seems bad to load the whole file into memory, even if its small in relation to RAM.
Initial i had my own file search that used keyword that allowed wildcards directly with the BaseStream, but this only works when there are contant values to identify.
I would have a keyword class and a method that takes a byte value, if that value matches the keyword at index 0 it incremets a counter so the next byte passed in is checked against index 1. if the count equals the keyword length then the function returns true (a match) then i can process.
I just think it would be good for regex to have a similar option because at the minute i can not handle a progress bar update until the regex has found matches. Possibly regex was not meant for file searching and more for validation of string values.
Anyway lol, thanks again
If only MySelf.Visible was more than just a getter...
A person can produce over 5 times there own body weight in excrement each year... please re-read your questions before posting
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Hi musefan,
whne you read text from a file, an encoding is used; you can specify one explicitly, most methods (e.g. File.ReadAllText) allow you to specify one; or you get your system's default encoding implicitly, which depends on regional settings.
I expect the regional setting ("code page") to be such that a lot of special characters get encoded in the byte value range [0x80, 0xFF], in order to save bytes in a file (and make it region-dependent!).
As an example, in Western Europe the default code page is 1252, which puts the Euro sign at 0x80, although there also is a Unicode character for it (0x20AC). So by default, reading a file containing 0x80 will result in a string with a 0x20AC at that position.
No, Regex does not work on files or streams, it needs a string.
No, progress indication is not really possible when you ask for a bulk operation such as File.ReadAllLines, a Regex operation, an SQL database operation, etc. Progress indication is available only when you implement it, which implies there are many steps in the job, possibly forcing you to cut the job in small steps (and forego the big methods such as ReadAllLines, and all Regex stuff).
I'm not a very big fan of Regex for your needs, I would have coded that with direct byte or char manipulations on the stream. Not sure whether I would chose bytes or chars though, probably bytes since your file does not really qualify as text, due to the 0xFF stuff.
Luc Pattyn [Forum Guidelines] [My Articles]
- before you ask a question here, search CodeProject, then Google
- the quality and detail of your question reflects on the effectiveness of the help you are likely to get
- use the code block button (PRE tags) to preserve formatting when showing multi-line code snippets
modified on Sunday, June 12, 2011 8:43 AM
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thanks for all the info
I have not really found a need for regex and in the past - i usually resort to manual manipulation for more control. but this time i just thought i should look into 'out the box' functions and start getting used to them.
I find every time i post a theory of how to do something manually i get knocked for being wrong for not using ready made class and functions, so maybe i need to start. but at the end of the day i will do what i think is best for the task at hand. which may involve changing manually handling the file as you suggested. The only issue is my OP example wasnt the complete regex expression, my requirement is more complex, but i can hand code if it comes to that.
Thanks
If only MySelf.Visible was more than just a getter...
A person can produce over 5 times there own body weight in excrement each year... please re-read your questions before posting
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musefan wrote: i get knocked for being wrong for not using ready made class and functions
Yes, there are lots of classes and methods that offer a compact solution for small problems, but in the end they typically aren't the best solution because they may take long to execute, consume much memory, and provide no feedback.
Regex is a powerful tool, but it still is a tool; you have to know it exists and use it when you feel it is the right approach for you. If the regex expression is so complex you can hardly understand it, then IMO you are better of coding something yourself, so you know what it does, how it does it, and you can debug and watch it.
Luc Pattyn [Forum Guidelines] [My Articles]
- before you ask a question here, search CodeProject, then Google
- the quality and detail of your question reflects on the effectiveness of the help you are likely to get
- use the code block button (PRE tags) to preserve formatting when showing multi-line code snippets
modified on Sunday, June 12, 2011 8:44 AM
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If only MySelf.Visible was more than just a getter...
A person can produce over 5 times there own body weight in excrement each year... please re-read your questions before posting
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Try using a binary reader instead of a text reader?
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Hi,
I've created a webservice and made that as a HTTPS one, but for some period of time i want to skip HTTPS certification validation, how can i do this? When i call using https:// it says connection couldn't be established. Is there any way to explicitly tell to skip this validation in C#
Thanks
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Hi,
I have this function in a DLL.
long MatchPage (long hImage, long hTemplateList, long *hMatch, char *szTemplate, long iMinMark, long bRegister, long *iConfidence);
Purpose
Match a filled form image to a Template from a Template List.
Parameters
hImage: Image handle of filled form
hTemplateList:Handle of the Template List.
hMatch:Handle of a Match which can be used later by JIRegionsRecognize. The handle should be free later by JIMatchFree.
szTemplate:Template file name is returned here. File name is returned without path and without file name extension.
iMinMark:Minimal confidence for a match. Legal values are 0-100. Recommended value is 15.
bRegister:If 1, the registered image is returned in hImage if matching achieved.
iConfidence:Confidence of the Match.
Import in this way:
[DllImport("image.dll")]
public static extern long MatchPage(IntPtr hImage, IntPtr hTemplateList, out IntPtr hMatch, [MarshalAs(UnmanagedType.LPStr)] StringBuilder szTemplate, long iMinMark, long bRegister, out IntPtr iConfidence);
...and call in this way:
rc = (int) MatchPage(hImage, hTemplateList, out hMatch, matchingTemplate, 25, 1, out iConfidence);
but the compiler says:"Access Violation" .
Someone can help me please?
TY
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It's not polite to double post your question. Nine posts down...[^]
"we must lose precision to make significant statements about complex systems."
-deKorvin on uncertainty
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You are right, sorry.......
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I've created a program that does all the parsing that I want and need in c#. the parsed information is bassically a bunch of xy coordanates and some other information. What i need to do next is take that information and create an animation for a robot simulator. Now someone mentioned to me flash would be the easiest and have the smoothiest animations, much smoother then c# can offer for sure. I tend to agree. Now Im not sure how I would integrate the two programs, c# parsing, flash animating. Now that same person who suggested flash also suggested i abandon c# and start using a program called autoit as it has a very simple function that allows autoit and flash to communicate. Ive taken a look at autoit and so far just cant seem to get much out it. Very frustrating as I have a working program already and keep looking back at c#.
Now what Im asking is any opinions on my situation? Is there any easy way to pass information from c# to flash or is autoit worth the time learning?
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You may use Windows Presentation Foundation (WPF) instead of Flash, and you can use your C# code in WPF application.
Calin
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where would you put the skill level required to get a WPF app up and running?
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It's not all that bad if you have something like ASP.NET programming in your background where you have some XML that dictates the look-and-feel of your application and some code in a "code-behind" class that controls the app.
You can find information at this site: WindowsClient.net[^].
Of course, if you have access to a Sam's Teach Yourself WPF in 24 Hours kind of book, that might make more sense in bringing you up to speed on the philosophy behind the design of WPF.
"we must lose precision to make significant statements about complex systems."
-deKorvin on uncertainty
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Hi
as u know, in Visual Studio DataSet Designer, each column of table is a DataColumn object and DataColumn object has a property named Caption. when i change this property of columns in dataSet designer and bind my datagridview.DataSource to that DataTable object, it does not display Caption text in DataGridView.Column.HeaderText (it display Name property from DataColumn object), wheras i want to display it's Caption.
my problem is that, is there any way to map DataGridView.Column.HeaderText to DataColumn.Caption property automatically ?
Thanks
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Hello All,
I have a particular problem that I am hoping someone can give me a better way of acheiving something.
I have a web page with some predefined search options. I want to give the user a way to create an adHoc search that could have up to 5 elements for the criteria.
So I thought of associating a numeric or alpha character to each element and then do check for a pattern on the postback. This option is becoming cumbersome and I know there has got to be a better way of doing this.
Any suggestions would be greatly appreciated. For those who don't answer, have a great day.
Fred
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I did create 5 fields but what if the user doesn't want to utilize all the fields. For example they might want to use "Create Date" and "User". Another user might want to search by "Status", "User" and "Create Date".
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Then what is the problem. Pass the parameters to your stored procedure if they are provided, null if not, and then use the appropriate where clause to restrict the results. If you aren't using a database, LINQ will do the same thing in its where clause.
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Sorry to have been a bother. I just wasn't thinking for some reason. Thanks!
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