Remove String After Determinate String - c#

I need to remove certain strings after another string within a piece of text.
I have a text file with some URLs and after the URL there is the RESULT of an operation. I need to remove the RESULT of the operation and leave only the URL.
Example of text:
http://website1.com/something Result: OK(registering only mode is on)
http://website2.com/something Result: Problems registered 100% (SOMETHING ELSE) Other Strings;
http://website3.com/something Result: error: "Âíèìàíèå, îáíàðóæåíà îøèáêà - Ìåñòî æèòåëüñòâà ñîäåðæèò íåäîïóñòèìûå ê
I need to remove all strings starting from Result: so the remaining strings have to be:
http://website1.com/something
http://website2.com/something
http://website3.com/something
Without Result: ........
The results are generated randomly so I don't know exactly what there is after RESULT:

One option is to use regular expressions as per some other answers. Another is just IndexOf followed by Substring:
int resultIndex = text.IndexOf("Result:");
if (resultIndex != -1)
{
text = text.Substring(0, resultIndex);
}
Personally I tend to find that if I can get away with just a couple of very simple and easy to understand string operations, I find that easier to get right than using regex. Once you start going into real patterns (at least 3 of these, then one of those) then regexes become a lot more useful, of course.

string input = "Action2 Result: Problems registered 100% (SOMETHING ELSE) Other Strings; ";
string pattern = "^(Action[0-9]*) (.*)$";
string replacement = "$1";
Regex rgx = new Regex(pattern);
string result = rgx.Replace(input, replacement);
You use $1 to keep the match ActionXX.

Use Regex for this.
Example:
var r = new System.Text.RegularExpressions.Regex("Result:(.)*");
var result = r.Replace("Action Result:1231231", "");
Then you will have "Action" in the result.

You can try with this code - by using string.Replace
var pattern = "Result:";
var lineContainYourValue = "jdfhkjsdfhsdf Result:ljksdfljh"; //I want replace test
lineContainYourValue.Replace(pattern,"");

Something along the lines of this perhaps?
string line;
using ( var reader = new StreamReader ( File.Open ( #"C:\temp\test.txt", FileMode.Open ) ) )
using ( var sw = new StreamWriter(File.Open( #"C:\Temp\test.edited.txt", FileMode.CreateNew ) ))
while ( (line = reader.ReadLine()) != null )
if(!line.StartsWith("Result:")) sw.WriteLine(line);

You can use RegEx for this kind of processing.
using System.Text.RegularExpressions;
private string ParseString(string originalString)
{
string pattern = ".*(?=Result:.*)";
Match match = Regex.Match(originalString, pattern);
return match.Value;
}

A Linq approach:
IEnumerable<String> result = System.IO.File
.ReadLines(path)
.Where(l => l.StartsWith("Action") && l.Contains("Result"))
.Select(l => l.Substring(0, l.IndexOf("Result")));

Given your current example, where you want only the website, regex match the spaces.
var fileLine = "http://example.com/sub/ random text";
Regex regexPattern = new Regex("(.*?)\\s");
var websiteMatch = regexPattern.Match(fileLine).Groups[1].ToString();
Debug.Print("!" + websiteMatch + "!");
Repeating for each line in your text file. Regex explained: .* matches anything, ? makes the match ungreedy, (brackets) puts the match into a group, \\s matches whitespace.

Related

C# split by regex

I have a little problem that I don't know how to call it like, so I will do my best to explain you that.
String text = "Random text over here boyz, I dunno what to do";
I want to take by split only over here boyz for example, I want to let split the word text and the word , and it will show me the whole text that in thoose 2 strings. Any ideas?
Thank you,
Sagi.
From your comments I get that from this string:
foo bar id="baz" qux
You want to obtain the value baz, because it is in the id="{text}" pattern.
For that you can use a regular expression:
string result = Regex.Match(text, "id=\"(.*?)\"").Groups[1].Value;
Note that this will match any character. Also note that this will yield false positives, like fooid="bar", and that this won't match unquoted values.
So all in all, for parsing HTML, you should not use regular expressions. Try HtmlAgilityPack and an XPath expression.
There is a Split overload that can receive multiple string seperators:
var rrr = text.Split(new string[] { ",", "text" }, StringSplitOptions.None);
If you would like to extract only the text between these two strings using regex you can do something like this:
var pattern = #"text(.*),";
var a = new Regex(pattern).Match(text);
var result = a.Groups[1];
You can use Regex class:
https://msdn.microsoft.com/pl-pl/library/ze12yx1d%28v=vs.110%29.aspx
But first of all (as it was said) you need to clarify for yourself how you will identify string that you want.
in first case you can use
string stringResult;
if (text.Contains("over here boyz"))
stringResult = string.Empty;
else
stringResult = "over here boyz";
but the second case can solve by this code
String text = "Random text over here boyz, I dunno what to do";
//Second dream without whitespace
var result = Regex.Split(text, " *text *| *, *");
foreach (var x in result)
{
Console.WriteLine(x);
}
//Second dream with whitespace
result = Regex.Split(text, "text|,");
foreach (var x in result)
{
Console.WriteLine(x);
}
You can train to write Regex with this tool http://www.regexbuddy.com/ or http://www.regexr.com/

Regex to find and replace a year in a string

I have a string in my c#:
The.Big.Bang.Theory.(2013).S07E05.Release.mp4
I need to find an occurance of (2013), and replace the whole thing, including the brackets, with _ (Three underscores). So the output would be:
The.Big.Bang.Theory._.S07E05.Release.mp4
Is there a regex that can do this? Or is there a better method?
I then do some processing on the new string - but later, need to report that '(2013)' was removed .. so I need to store the value that is replaced.
Tried with your string. It works
string pattern = #"\(\d{4}\)";
string search = "The.Big.Bang.Theory.(2013).S07E05.Release.mp4";
var m = Regex.Replace(search, pattern, "___");
Console.WriteLine(m);
This will find any 4 digits number enclosed in open/close brakets.
If the year number can change, I think that Regex is the best approach .
Instead this code will tell you if there a match for your pattern
var k = Regex.Matches(search, pattern);
if(k.Count > 0)
Console.WriteLine(k[0].Value);
Many of these answers forgot the original question in that you wanted to know what you are replacing.
string pattern = #"\((19|20)\d{2}\)";
string search = "The.Big.Bang.Theory.(2013).S07E05.Release.mp4";
string replaced = Regex.Match(search, pattern).Captures[0].ToString();
string output = Regex.Replace(search, pattern, "___");
Console.WriteLine("found: {0} output: {1}",replaced,output);
gives you the output
found: (2013) output: The.Big.Bang.Theory.___.S07E05.Release.mp4
Here is an explanation of my pattern too.
\( -- match the (
(19|20) -- match the numbers 19 or 20. I assume this is a date for TV shows or movies from 1900 to now.
\d{2} -- match 2 more digits
\) -- match )
Here is a working snippet from a console application, note the regex \(\d{4}\):
var r = new System.Text.RegularExpressions.Regex(#"\(\d{4}\)");
var s = r.Replace("The.Big.Bang.Theory.(2013).S07E05.Release.mp4", "___");
Console.WriteLine(s);
and the output from the console application:
The.Big.Bang.Theory.___.S07E05.Release.mp4
and you can reference this Rubular for proof.
Below is a modified solution taking into consideration your additional requirement:
var m = r.Match("The.Big.Bang.Theory.(2013).S07E05.Release.mp4");
if (m.Success)
{
var s = "The.Big.Bang.Theory.(2013).S07E05.Release.mp4".Replace(m.Value, "___");
var valueReplaced = m.Value;
}
Try this:
string s = "The.Big.Bang.Theory.(2013).S07E05.Release.mp4";
var info = Regex.Split(
Regex.Matches(s, #"\(.*?\)")
.Cast<Match>().First().ToString(), #"[\s,]+");
s = s.Replace(info[0], "___");
Result
The.Big.Bang.Theory.___.S07E05.Release.mp4
try this :
string str="The.Big.Bang.Theory.(2013).S07E05.Release.mp4";
var matches = Regex.Matches(str, #"\([0-9]{4}\)");
List<string> removed=new List<string>();
if (matches.Count > 0)
{
for (int i = 0; i < matches.Count; i++)
{
List.add(matches.value);
}
}
str=Regex.replace(str,#"\([0-9]{4}\)","___");
System.out.println("Removed Strings are:")
foreach(string s in removed )
{
System.out.println(s);
}
output:
Removed Strings are:
(2013)
You don't need a regex for a simple replace (you can use one, but's it's not needed)
var name = "The.Big.Bang.Theory.(2013).S07E05.Release.mp4";
var replacedName = name.Replace("(2013)", "___");

how can i optimize the performance of this regular expression?

I'm using a regular expression to replace commas that are not contained by text qualifying quotes into tab spaces.
I'm running the regex on file content through a script task in SSIS. The file content is over 6000 lines long.
I saw an example of using a regex on file content that looked like this
String FileContent = ReadFile(FilePath, ErrInfo);
Regex r = new Regex(#"(,)(?=(?:[^""]|""[^""]*"")*$)");
FileContent = r.Replace(FileContent, "\t");
That replace can understandably take its sweet time on a decent sized file.
Is there a more efficient way to run this regex?
Would it be faster to read the file line by line and run the regex per line?
It seems you're trying to convert comma separated values (CSV) into tab separated values (TSV).
In this case, you should try to find a CSV library instead and read the fields with that library (and convert them to TSV if necessary).
Alternatively, you can check whether each line has quotes and use a simpler method accordingly.
The problem is the lookahead, which looks all the way to the end on each comman, resulting in O(n2) complexity, which is noticeable on long inputs. You can get it done in a single pass by skipping over quotes while replacing:
Regex csvRegex = new Regex(#"
(?<Quoted>
"" # Open quotes
(?:[^""]|"""")* # not quotes, or two quotes (escaped)
"" # Closing quotes
)
| # OR
(?<Comma>,) # A comma
",
RegexOptions.IgnorePatternWhitespace);
content = csvRegex.Replace(content,
match => match.Groups["Comma"].Success ? "\t" : match.Value);
Here we match free command and quoted strings. The Replace method takes a callback with a condition that checks if we found a comma or not, and replaced accordingly.
The simplest optimization would be
Regex r = new Regex(#"(,)(?=(?:[^""]|""[^""]*"")*$)", RegexOptions.Compiled);
foreach (var line in System.IO.File.ReadAllLines("input.txt"))
Console.WriteLine(r.Replace(line, "\t"));
I haven't profiled it, but I wouldn't be surprised if the speedup was huge.
If that's not enough I suggest some manual labour:
var input = new StreamReader(File.OpenRead("input.txt"));
char[] toMatch = ",\"".ToCharArray ();
string line;
while (null != (line = input.ReadLine()))
{
var result = new StringBuilder(line);
bool inquotes = false;
for (int index=0; -1 != (index = line.IndexOfAny (toMatch, index)); index++)
{
bool isquote = (line[index] == '\"');
inquotes = inquotes != isquote;
if (!(isquote || inquotes))
result[index] = '\t';
}
Console.WriteLine (result);
}
PS: I assumed #"\t" was a typo for "\t", but perhaps it isn't :)

c# Regex question

I have a problem dealing with the # symbol in Regex, I am trying to remove #sometext
from a text string can't seem to find anywhere where it uses the # as a literal. I have tried myself but doesn't remove the word from the string. Any ideas?
public string removeAtSymbol(string input)
{
Regex findWords = new Regex(______);//Find the words like "#text"
Regex[] removeWords;
string test = input;
MatchCollection all = findWords.Matches(test);
removeWords = new Regex[all.Count];
int index = 0;
string[] values = new string[all.Count];
YesOutputBox.Text = " you got here";
foreach (Match m in all) //List all the words
{
values[index] = m.Value.Trim();
index++;
YesOutputBox.Text = YesOutputBox.Text + " " + m.Value;
}
for (int i = 0; i < removeWords.Length; i++)
{
removeWords[i] = new Regex(" " + values[i]);
// If the words appears more than one time
if (removeWords[i].Matches(test).Count > 1)
{
removeWords[i] = new Regex(" " + values[i] + " ");
test = removeWords[i].Replace(test, " "); //Remove the first word.
}
}
return test;
}
You can remove all occurences of "#sometext" from string test via the method
Regex.Replace(test, "#sometext", "")
or for any word starting with "#" you can use
Regex.Replace(test, "#\\w+", "")
If you need specifically a separate word (i.e. nothing like #comp within tom#comp.com) you may preceed the regex with a special word boundary (\b does not work here):
Regex.Replace(test, "(^|\\W)#\\w+", "")
You can use:
^\s#([A-Za-z0-9_]+)
as the regex to recognize Twitter usernames.
Regex to remove #something from this string: I want to remove #something from this string.
var regex = new Regex("#\\w*");
string result = regex.Replace(stringWithAt, "");
Is that what you are looking for?
I've had good luck applying this pattern:
\B#\w+
This will match any string starting with an # character that contains alphanumeric characters, plus some linking punctuation like the underscore character, if it does not occur on a boundary between alphanumeric and non-alphanumeric characters.
The result of executing this code:
string result = Regex.Replace(
#"#This1 #That2_thing this2#3that #the5Others #alpha#beta#gamma",
#"\B#\w+",
#"redacted");
is the following string:
redacted redacted this2#3that redacted redacted#beta#gamma
If this question is Twitter-specific, then Twitter provides an open source library that helps capture Twitter-specific entities like links, mentions and hashtags. This java file contains the code defining the regular expressions that Twitter uses, and this yml file contains test strings and expected outcomes of many unit tests that exercise the regular expressions in the Twitter library.
Twitter's mention-matching pattern (extracted from their library, modified to remove unnecessary capture groups, and edited to make sense in the context of a replacement) is shown below. The match should be performed in a case-insensitive manner.
(^|[^a-z0-9_])[#\uFF20][a-z0-9_]{1,20}
Here is an example which reproduces the results of the first replacement in my answer:
string result = Regex.Replace(
#"#This1 #That2_thing this2#3that #the5Others #alpha#beta#gamma",
#"(^|[^a-z0-9_])[#\uFF20][a-z0-9_]{1,20}",
#"$1redacted",
RegexOptions.IgnoreCase);
Note the need to include the substitution $1 since the first capture group can't be directly converted into an atomic zero-width assertion.

Regular Expression to match numbers inside parenthesis inside square brackets with optional text

Firstly, I'm in C# here so that's the flavor of RegEx I'm dealing with. And here are thing things I need to be able to match:
[(1)]
or
[(34) Some Text - Some Other Text]
So basically I need to know if what is between the parentheses is numeric and ignore everything between the close parenthesis and close square bracket. Any RegEx gurus care to help?
This should work:
\[\(\d+\).*?\]
And if you need to catch the number, simply wrap \d+ in parentheses:
\[\((\d+)\).*?\]
Do you have to match the []? Can you do just ...
\((\d+)\)
(The numbers themselves will be in the groups).
For example ...
var mg = Regex.Match( "[(34) Some Text - Some Other Text]", #"\((\d+)\)");
if (mg.Success)
{
var num = mg.Groups[1].Value; // num == 34
}
else
{
// No match
}
Regex seems like overkill in this situation. Here is the solution I ended up using.
var src = test.IndexOf('(') + 1;
var dst = test.IndexOf(')') - 1;
var result = test.SubString(src, dst-src);
Something like:
\[\(\d+\)[^\]]*\]
Possibly with some more escaping required?
How about "^\[\((d+)\)" (perl style, not familiar with C#). You can safely ignore the rest of the line, I think.
Depending on what you're trying to accomplish...
List<Boolean> rslt;
String searchIn;
Regex regxObj;
MatchCollection mtchObj;
Int32 mtchGrp;
searchIn = #"[(34) Some Text - Some Other Text] [(1)]";
regxObj = new Regex(#"\[\(([^\)]+)\)[^\]]*\]");
mtchObj = regxObj.Matches(searchIn);
if (mtchObj.Count > 0)
rslt = new List<bool>(mtchObj.Count);
else
rslt = new List<bool>();
foreach (Match crntMtch in mtchObj)
{
if (Int32.TryParse(crntMtch.Value, out mtchGrp))
{
rslt.Add(true);
}
}
How's this? Assuming you only need to determine if the string is a match, and need not extract the numeric value...
string test = "[(34) Some Text - Some Other Text]";
Regex regex = new Regex( "\\[\\(\\d+\\).*\\]" );
Match match = regex.Match( test );
Console.WriteLine( "{0}\t{1}", test, match.Success );

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