Substring from path string - c#

In strings like this (I get strings from Directory.GetFiles())
string temp = "\\folder_name\\file_name.filetype.[somename#somedomain].wallet"
What is the best way to substring: file_name.filetype
I could do something like this:
const string source = ".[somename#somedomain].wallet";
temp.Substring(0, temp.IndexOf(source, StringComparison.Ordinal));
... but problem is that "mail" in string ".[xxxx#xxxx].wallet" is changing, in my words my string source should be something like this:
const string source = ".[*].wallet"; //so all strings that are in .[all_strings].wallet
Is there an easy way to do something like this (with asterisk "*"), or I will have to substring piece by piece and concatenate this new string?


You can construct a regex that requires a backslash before the substring of interest, and a text in square brackets followed by .wallet at the end.
Here is how you can do with in C# regex APIs:
string temp = #"\folder_name\file_name.filetype.[somename#somedomain].wallet";
var m = Regex.Match(temp, #"(?<=\\)[^.]*\.[^.]*(?=\.\[[^\]]*\].wallet)");
if (m.Success) {
Console.WriteLine(m.Value);
} else {
Console.WriteLine("<no match>");
}
Demo.
(?<=...) and (?=...) constructs are zero-length look-ahead and look-behind. They are not included in the m.Value.


You could search for the 2nd index of . and take everything before that point.
string temp = "\\folder_name\\file_name.filetype.[somename#somedomain].wallet";
var filename = Path.GetFileName(temp);
var lastIndex = filename.IndexOf('.', filename.IndexOf('.') + 1);
var fileYouAreLookingFor = filename.Substring(0, lastIndex);
Working fiddle


You could also use an regex to achieve this. The first group of the following one should be what you are looking for.
string temp = "\\folder_name\\file_name.filetype.[somename#somedomain].wallet";
var filenameRegex = new Regex("^.*\\\\(.*)\\.\\[.*\\]\\.wallet$");
var match = filenameRegex.Match(temp);
var result = match.Groups[1];

Related

Substring or split word in clamp

I need an solution for my problem. I have a clause like:
Hello guys I am cool (test)
An now I need an effective method to split just only the part in the parentheses and the result should be:
test
My try is to split the String in words like. But I don't think it is the best way.
string[] words = s.Split(' ');

I do not think that split is the solution to your problem
Regex is very good for extracting data.
using System.Text.RegularExpression;
...
string result = Regex.Match(s, #"\((.*?)\)").Groups[1].Value;
This should do the trick.

Assuming:
var input = "Hello guys I am cool (test)";
..Non-Regex version:
var nonRegex = input.Substring(input.IndexOf('(') + 1, input.LastIndexOf(')') - (input.IndexOf('(') + 1));
..Regex version:
var regex = Regex.Match(input, #"\((\w+)\)").Groups[1].Value;

You can use regex for this:
string parenthesized = Regex.Match(s, #"(?<=\()[^)]+(?=\))").Value;
Here's an explanation of the various parts of the regex pattern:
(?<=\(): Lookbehind for the ( (excluded from the match)
[^)]+: Sequence of characters consisting of anything except )
(?=\)): Lookahead for the ) (excluded from the match)

The most efficient way is using string methods but you don't need Split but Substring and IndexOf. Note that this currently just finds a single word in parentheses:
string text = "Hello guys I am cool (test)";
string result = "--no parentheses--";
int index = text.IndexOf('(');
if(index++ >= 0) // ++ used to look behind ( which is a single character
{
int endIndex = text.IndexOf(')', index);
if(endIndex >= 0)
{
result = text.Substring(index, endIndex - index);
}
}

string s = "Hello guys I am cool (test)";
var result = s.Substring(s.IndexOf("test"), 4);

how to remove special char from the string and make new string?

I have a string 4(4X),4(4N),3(3X) from this string I want to make string 4,4,3. If I am getting the string 4(4N),3(3A),2(2X) then I want to make my string 4,3,2.
Please someone tell me how can I solve my problem.

This Linq query selects substring from each part of input string, starting from beginning till first open brace:
string input = "4(4N),3(3A),2(2X)";
string result = String.Join(",", input.Split(',')
.Select(s => s.Substring(0, s.IndexOf('('))));
// 4,3,2

This may help:
string inputString = "4(4X),4(4N),3(3X)";
string[] temp = inputString.Split(',');
List<string> result = new List<string>();
foreach (string item in temp)
{
result.Add(item.Split('(')[0]);
}
var whatYouNeed = string.Join(",", result);

You can use regular expressions
String input = #"4(4X),4(4N),3(3X)";
String pattern = #"(\d)\(\1.\)";
// ( ) - first group.
// \d - one number
// \( and \) - braces.
// \1 - means the repeat of first group.
String result = Regex.Replace(input, pattern, "$1");
// $1 means, that founded patterns will be replcaed by first group
//result = 4,4,3

How to remove the exact occurence of characters from a string?

For Example, I have a string like :
string str = "santhosh,phani,ravi,phani123,praveen,sathish,prakash";
I want to delete the charaters ,phani from str.
Now, I am using str = str.Replace(",phani", string.Empty);
then my output is : str="santhosh,ravi123,praveen,sathish,prakash";
But I want a output like : str="santhosh,ravi,phani123,praveen,sathish,prakash";

string str = "santhosh,phani,ravi,phani123,praveen,sathish,prakash";
var words = str.Split(',');
str = String.Join(",", words.Where(word => word != "phani"));

the better choice is to use a Split and Join method.
Easy in Linq :
String str = "santhosh,phani,ravi,phani123,praveen,sathish,prakash";
String token = "phani";
String result = String.Join(",", str.Split(',').Where(s => s != token));
(edit : I take time for testing and i'm not first ^^)

String.join(",", str.split(',').ToList().remove("phani"));
Removes any given name from the list.

How about
str = str.Replace(",phani,", ",");
This, however, does not work if "phani" is the last item in the string. To get around this, you could do this:
string source = "...";
source += ","; // Explicitly add a comma to the end
source = source.Replace(",phani,", ",").TrimEnd(',');
This adds a comma, replaces "phani" and removes the trailing comma.
A third solution would be this:
str = String.Join(",", str.Split(',').ToList().Remove("phani").ToArray());

Try to use with comma instead of;
string str = "santhosh,ravi,phani,phani123,praveen,sathish,prakash";
str = str.Replace(",phani,", ",");
Console.WriteLine(str);
Output will be;
santhosh,ravi,phani123,praveen,sathish,prakash
Here is a DEMO.
As Davin mentioned in comment, this won't work if phani is last item in the string. Silvermind's answer looks like the right answer.

string str = "santhosh,phani,ravi,phani123,praveen,sathish,prakash";
string pattern = #"\b,phani,\b";
string replace = ",";
Console.WriteLine(Regex.Replace(str, pattern, replace));
Output:
santhosh,ravi,phani123,praveen,sathish,prakash

You may use the regular expression, but you have to take care of cases when your string starts or ends with the substring:
var pattern = #",?\bphani\b,?";
var regex = new Regex(pattern);
var result = regex.Replace(input, ",").Trim(',');
Shorter notation could look like this:
var result = Regex.Replace(input, #",?\bphani\b,?", ",").Trim(',');
Explanation of the regular expression: ,?\bphani\b,? matches the word phani, but only if preceded and followed by word-delimiter characters (because of the word boundary metacharacter \b), and it can be (but doesn't have to be) preceded and followed by the comma thanks to ,? which means none or more comma(s).
At the end we need to remove possible commas from the beginning and end of the string, that's why there's Trim(',') on the result.

C# regular expression to find custom markers and take content

I have a string:
productDescription
In it are some custom tags such as:
[MM][/MM]
For example the string might read:
This product is [MM]1000[/MM] long
Using a regular expression how can I find those MM tags, take the content of them and replace everything with another string? So for example the output should be:
This product is 10 cm long

I think you'll need to pass a delegate to the regex for that.
Regex theRegex = new Regex(#"\[MM\](\d+)\[/MM\]");
text = theRegex.Replace(text, delegate(Match thisMatch)
{
int mmLength = Convert.ToInt32(thisMatch.Groups[1].Value);
int cmLength = mmLength / 10;
return cmLength.ToString() + "cm";
});

Using RegexDesigner.NET:
using System.Text.RegularExpressions;
// Regex Replace code for C#
void ReplaceRegex()
{
// Regex search and replace
RegexOptions options = RegexOptions.None;
Regex regex = new Regex(#"\[MM\](?<value>.*)\[\/MM\]", options);
string input = #"[MM]1000[/MM]";
string replacement = #"10 cm";
string result = regex.Replace(input, replacement);
// TODO: Do something with result
System.Windows.Forms.MessageBox.Show(result, "Replace");
}
Or if you want the orginal text back in the replacement:
Regex regex = new Regex(#"\[MM\](?<theText>.*)\[\/MM\]", options);
string replacement = #"${theText} cm";

A regex like this
\[(\w+)\](\d+)\[\/\w+\]
will find and collect the units (like MM) and the values (like 1000). That would at least allow you to use the pairs of parts intelligently to do the conversion. You could then put the replacement string together, and do a straightforward string replacement, because you know the exact string you're replacing.
I don't think you can do a simple RegEx.Replace, because you don't know the replacement string at the point you do the search.

Regex rex = new Regex(#"\[MM\]([0-9]+)\[\/MM\]");
string s = "This product is [MM]1000[/MM] long";
MatchCollection mc = rex.Matches(s);
Will match only integers.
mc[n].Groups[1].Value;
will then give the numeric part of nth match.

C#: Parse substring from a string by detecting whitespace

If I have various strings that have text followed by whitespace followed by text, how can I parse the substring beginning with the first character in the second block of text?
For example:
If I have the string:
"stringA stringB"
How can I extract the substring
"stringB"
The strings are of various lengths but will all be of the format .
I'm sure this can be easily done with regex but I'm having trouble finding the proper syntax for c#.

No RegEx needed, just split it.
var test = "stringA stringB";
var second = test.Split()[1];
and if you are in the wonderful LINQ-land
var second = "string1 string2".Split().ElementAtOrDefault(1);
and with RegEx (for completeness)
var str2 = Regex.Match("str1 str2", #"\w (.*$)").Groups[1].Value;

use string.Split()
var test = "stringA stringB";
var elements = test.Split(new[]
{
' '
});
var desiredItem = elements.ElementAtOrDefault(1);
if you want to capture all whitespaces (msdn tells us more):
var test = "stringA stringB";
//var elements = test.Split(); // pseudo overload
var elements = test.Split(null); // correct overload
var desiredItem = elements.ElementAtOrDefault(1);
edit:
why pseudo-overload?
.Split() gets compiled to .Split(new char[0])
not documented in MSDN

If all strings are separated by a whitespace you don't need a regex here. You could just use the Split() method:
string[] result = { };
string myStrings = "stringA stringB stringC";
result = myStrings.Split(' ');

You don't need event the Split(). I think a simple IndexOf/Substring will do the job.
var input = "A B";
var result = string.Empty;
var index = input.IndexOf(' ');
if (index >= 0)
{
result = input.Substring(index + 1);
}

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