Develop Reference

C# Get particular string between two string (multiple occurance)

how can I retrieve both string between STRING & END in this sentence
"This is STRING a222 END, and this is STRING b2838 END."
strings that I want to get:
a222
b2838
Following is my code, and i only manage to get first string which is a222
string myString = "This is STRING a222 END, and this is STRING b2838 END.";
int first = myString.IndexOf("STRING") + "STRING".Length;
int second= myString.LastIndexOf("END");
string result = St.Substring(first, second - first);
.

Here is the solution using Regular Expressions. Working Code here
var reg = new Regex("(?<=STRING ).*?(?= END)");
var matched = reg.Matches("This is STRING a222 END, and this is STRING b2838 END.");
foreach(var m in matched)
{
Console.WriteLine(m.ToString());
}

You can pass a value for startIndex to string.IndexOf(), you can use this while looping:
IEnumerable<string> Find(string input, string startDelimiter, string endDelimiter)
{
int first = 0, second;
do
{
// Find start delimiter
first = input.IndexOf(startDelimiter, startIndex: first) + startDelimiter.Length;
if (first == -1)
yield break;
// Find end delimiter
second = input.IndexOf(endDelimiter, startIndex: first);
if (second == -1)
yield break;
yield return input.Substring(first, second - first).Trim();
first = second + endDelimiter.Length + 1;
}
while (first < input.Length);
}

You can iterate over indexes,
string myString = "This is STRING a222 END, and this is STRING b2838 END.";
//Jump to starting index of each `STRING`
for(int i = myString.IndexOf("STRING");i > 0; i = myString.IndexOf("STRING", i+1))
{
//Get Index of each END
var endIndex = myString.Substring(i + "STARTING".Length).IndexOf("END");
//PRINT substring between STRING and END of each occurance
Console.WriteLine(myString.Substring(i + "STARTING".Length-1, endIndex));
}
.NET FIDDLE
In your case, STRING..END occurs multiple times, but you were getting index of only first STRING and last index of END which will return substring, starts with first STRING to last END.
i.e.
a222 END, and this is STRING b2838

You've already got some good answers but I'll add another that uses ReadOnlyMemory from .NET core. That provides a solution that doesn't allocate new strings which can be nice. C# iterators are a common way to transform one sequence, of chars in this case, into another. This method would be used to transform the input string into sequence of ReadOnlyMemory each containing the tokens your after.
public static IEnumerable<ReadOnlyMemory<char>> Tokenize(string source, string beginPattern, string endPattern)
{
if (string.IsNullOrEmpty(source) ||
string.IsNullOrEmpty(beginPattern) ||
string.IsNullOrEmpty(endPattern))
yield break;
var sourceText = source.AsMemory();
int start = 0;
while (start < source.Length)
{
start = source.IndexOf(beginPattern, start);
if (-1 != start)
{
int end = source.IndexOf(endPattern, start);
if (-1 != end)
{
start += beginPattern.Length;
yield return sourceText.Slice(start, (end - start));
}
else
break;
start = end + endPattern.Length;
}
else
{
break;
}
}
}
Then you'd just call it like so to iterate over the tokens...
static void Main(string[] args)
{
const string Source = "This is STRING a222 END, and this is STRING b2838 END.";
foreach (var token in Tokenize(Source, "STRING", "END"))
{
Console.WriteLine(token);
}
}

string myString = "This is STRING a222 END, and this is STRING b2838 END.";
// Fix the issue based on #PaulF's comment.
if (myString.StartsWith("STRING"))
myString = $"DUMP {myString}";
var arr = myString.Split(new string[] { "STRING", "END" }, StringSplitOptions.RemoveEmptyEntries);
for (int i = 0; i < arr.Length; i++)
{
if(i%2 > 0)
{
// This is your string
Console.WriteLine(arr[i].Trim());
}
}

Decode GSM 7 bit in C#

I need to decode GSM 7 bit to ascii string in c# so that I googled and found lots of different posts about it, this post is one of them but It is not a c#.
Can anyone please share a c# code that can decode GSM 7-bit Character to ASCII string.
Thanks.

class GSM7BitDecoder
{
// Basic Character Set
private const string BASIC_SET =
"#£$¥èéùìòÇ\nØø\rÅåΔ_ΦΓΛΩΠΨΣΘΞ\x1bÆæßÉ !\"#¤%&'()*+,-./0123456789:;<=>?" +
"¡ABCDEFGHIJKLMNOPQRSTUVWXYZÄÖÑܧ¿abcdefghijklmnopqrstuvwxyzäöñüà";
// Basic Character Set Extension
private const string EXTENSION_SET =
"````````````````````^```````````````````{}`````\\````````````[~]`" +
"|````````````````````````````````````€``````````````````````````";
string[] BASIC_SET_ARRAY = BASIC_SET.Select(x => x.ToString()).ToArray();
string[] EXTENSION_SET_ARRAY = EXTENSION_SET.Select(x => x.ToString()).ToArray();
enum circle { Start=1, Complete=8 }
string GetChar(string bin)
{
try
{
if (Convert.ToInt32(bin, 2).Equals(27))
return EXTENSION_SET_ARRAY[Convert.ToInt32(bin, 2)];
else
return BASIC_SET_ARRAY[Convert.ToInt32(bin, 2)];
}
catch { return string.Empty; }
}
public string DecodeGSM7bit(string strGsm7bit)
{
var suffix = string.Empty;
var septet = string.Empty;
var CurSubstr = string.Empty;
var counter = 1;
List<string> septets = new List<string>();
List<string> sectets = new List<string>();
//Prepare Octets
var octets = Enumerable.Range(0, strGsm7bit.Length / 2).Select(i =>
{
return Convert.ToString(Convert.ToInt64(strGsm7bit.Substring(i * 2, 2), 16), 2).PadLeft(8,'0');
}).ToList();
for (var index=0; index < octets.Count; index = index +1)
{
//Generate Septets
septet = octets[index].Substring(counter);
CurSubstr = octets[index].Substring(0, counter);
if (counter.Equals((int)circle.Start))
septets.Add(septet);
else
septets.Add(septet + suffix);
//Organize Sectets
sectets.Add(GetChar(septets[index]));
suffix = CurSubstr;
counter++;
//Reset counter when the circle is complete.
if (counter == (int)circle.Complete)
{
counter = (int)circle.Start;
sectets.Add(GetChar(suffix));
}
}
return string.Join("", sectets);
}

How to convert Quoted-Print String

I'm working on French String in .NET
Decoding a Mail body , I receive "Chasn=C3=A9 sur illet"
I would like to get "Chasné sur illet"
and i don't find any solution aver 2 days web search.
C# ou VB.NET
Can anyone helps me ?
thanks

Or the easiest of all, just use the QuotedPrintableDecoder from my MimeKit library:
static string DecodeQuotedPrintable (string input, string charset)
{
var decoder = new QuotedPrintableDecoder ();
var buffer = Encoding.ASCII.GetBytes (input);
var output = new byte[decoder.EstimateOutputLength (buffer.Length)];
int used = decoder.Decode (buffer, 0, buffer.Length, output);
var encoding = Encoding.GetEncoding (charset);
return encoding.GetString (output, 0, used);
}
Note that the other answers above assume the decoded content will be ASCII or UTF-8, but that isn't necessarily the case. You'll need to get the charset parameter from the Content-Type header of the MIME part that you are decoding.
Of course... if you don't know how to get that info, you could simply use my awesome MailKit library to get the MIME part from IMAP and have it do all of this work for you.

This is UTF8 encoding.
Using this post:
http://www.dpit.co.uk/decoding-quoted-printable-email-in-c/
Here is the code (don't forget to accept the answer if helped):
using System;
using System.Text;
using System.Text.RegularExpressions;
namespace ConsoleApplication1
{
class Program
{
static void Main(string[] args)
{
Console.WriteLine(DecodeQuotedPrintable("Chasn=C3=A9 sur illet"));
Console.ReadKey();
}
static string DecodeQuotedPrintable(string input)
{
var occurences = new Regex(#"(=[0-9A-Z][0-9A-Z])+", RegexOptions.Multiline);
var matches = occurences.Matches(input);
foreach (Match m in matches)
{
byte[] bytes = new byte[m.Value.Length / 3];
for (int i = 0; i < bytes.Length; i++)
{
string hex = m.Value.Substring(i * 3 + 1, 2);
int iHex = Convert.ToInt32(hex, 16);
bytes[i] = Convert.ToByte(iHex);
}
input = input.Replace(m.Value, Encoding.UTF8.GetString(bytes));
}
return input.Replace("=rn", "");
}
}
}

From : https://stackoverflow.com/a/36803911/6403521
My solution :
[TestMethod]
public void TestMethod1()
{
Assert.AreEqual("La Bouichère", quotedprintable("La Bouich=C3=A8re", "utf-8"));
Assert.AreEqual("Chasné sur illet", quotedprintable("Chasn=C3=A9 sur illet", "utf-8"));
Assert.AreEqual("é è", quotedprintable("=C3=A9 =C3=A8", "utf-8"));
}
private string quotedprintable(string pStrIn, string encoding)
{
String strOut = pStrIn.Replace("=\r\n", "");
// Find the first =
int position = strOut.IndexOf("=");
while (position != -1)
{
// String before the =
string leftpart = strOut.Substring(0, position);
// get the QuotedPrintable String in a ArrayList
System.Collections.ArrayList hex = new System.Collections.ArrayList();
// The first Part
hex.Add(strOut.Substring(1 + position, 2));
// Look for the next parts
while (position + 3 < strOut.Length && strOut.Substring(position + 3, 1) == "=")
{
position = position + 3;
hex.Add(strOut.Substring(1 + position, 2));
}
// In the hex Array, we have two items
// Convert using the GetEncoding Function
byte[] bytes = new byte[hex.Count];
for (int i = 0; i < hex.Count; i++)
{
bytes[i] = System.Convert.ToByte(new string(((string)hex[i]).ToCharArray()), 16);
}
string equivalent = System.Text.Encoding.GetEncoding(encoding).GetString(bytes);
// Part of the orignal String after the last QP Symbol
string rightpart = strOut.Substring(position + 3);
// Re build the String
strOut = leftpart + equivalent + rightpart;
// find the new QP Position
position = leftpart.Length + equivalent.Length;
if (rightpart.Length == 0)
{
position = -1;
}
else
{
position = strOut.IndexOf("=", position + 1);
}
}
return strOut;
}

We had an issue with this method - that it is VERY slow.
The following enhanced performance A LOT
public static string FromMailTransferEncoding(this string messageText, Encoding enc, string transferEncoding)
{
if (string.IsNullOrEmpty(transferEncoding))
return messageText;
if ("quoted-printable".Equals(transferEncoding.ToLower()))
{
StringBuilder sb = new StringBuilder();
string delimitorRegEx = #"=[\r][\n]";
string[] parts = Regex.Split(messageText, delimitorRegEx);
foreach (string part in parts)
{
string subPart = part;
Regex occurences = new Regex(#"(=[0-9A-Z][0-9A-Z])+", RegexOptions.Multiline);
MatchCollection matches = occurences.Matches(subPart);
foreach (Match m in matches)
{
byte[] bytes = new byte[m.Value.Length / 3];
for (int i = 0; i < bytes.Length; i++)
{
string hex = m.Value.Substring(i * 3 + 1, 2);
int iHex = Convert.ToInt32(hex, 16);
bytes[i] = Convert.ToByte(iHex);
}
subPart = occurences.Replace(subPart, enc.GetString(bytes), 1);
}
sb.Append(subPart);
}
return sb.ToString();
}
return messageText;
}

static string ConverFromHex(string source)
{
string target = string.Empty;
int startPos = source.IndexOf('=', 0);
int prevStartPos = 0;
while (startPos >= 0)
{
// concat with substring from source
target += source.Substring(prevStartPos, startPos - prevStartPos);
// next offset
startPos++;
// update prev pos
prevStartPos = startPos;
// get substring
string hexString = source.Substring(startPos, 2);
// get int equiv
int hexNum = 0;
if (int.TryParse(hexString, System.Globalization.NumberStyles.AllowHexSpecifier, System.Globalization.CultureInfo.InvariantCulture, out hexNum))
{
// add to target string
target += (char)hexNum;
// add hex length
prevStartPos += 2;
}
// next occurence
startPos = source.IndexOf('=', startPos);
}
// add rest of source
target += source.Substring(prevStartPos);
return target;
}

Negate and increment value in binary system

I've got binary number and I need to:
1) negate all bytes
2) add 1 to negate number
So, I wrote this:
public string u2_number_plus = "1001";
public string u2_number_minus = "";
public string binToU2()
{
int length = u2_number_plus.Length;
int temp = 1;
//negate all bytes
for (int a = 0; a < length; a++)
{
if (u2_number_plus[a] == '1')
u2_number_minus += '0';
else
u2_number_minus += '1';
}
//add 1 to my new (because negate) number
for (int b = length - 1; b >= 0; b--)
{
if (u2_number_minus[b] == 0 && temp == 1)
{
u2_number_minus = u2_number_minus.Replace(u2_number_minus[b], '1');
temp = 0;
}
else if (u2_number_minus[b] == 1 && temp == 1)
{
u2_number_minus = u2_number_minus.Replace(u2_number_minus[b], '0');
temp = 1;
}
else
break;
}
return u2_number_minus;
}
My function binToU2() returns negate but not increment value.
If input data is 1001 I should get 0111, but function returns just 0110. Where I made a mistake?

When you are doing the checking of u2_number_minus[b] you need to compare it against '0' and '1' not the number 0 and 1.
if (u2_number_minus[b] == '0' && temp == 1)
There is also another error, the use of Replace changes all occurrences of the specified character in the string, but we only want to change the one at the specified position. C# does not have replaceAt, but a helper function can be created to do this. See Replacing a char at a given index in string?. I used Jon Skeet's code here:
public static class ReplaceHelper
{
public static string ReplaceAt(this string input, int index, char newChar)
{
if (input == null)
{
throw new ArgumentNullException("input");
}
char[] chars = input.ToCharArray();
chars[index] = newChar;
return new string(chars);
}
}
and change the Replace lines to use ReplaceAt eg
u2_number_minus = u2_number_minus.ReplaceAt(b, '1');

don't really get what you want to do or where you need this for, but anyways, maybe you want to use a BitArray instead of struggling with string manipulation.
BitArray is actually storing bits and gives you basic functionality to negate the array or use other operations...
Let me give you an example:
// define a bit array with length=4 and false as default value for each bit.
var bits = new BitArray(4, false);
bits.Not(); // negate --> all 4 bits are now true.
// your example:
bits = new BitArray(new bool[] { true, false, false, true });
// to inverst/negate it
bits.Not();
// convert to string:
string bitString = string.Empty;
foreach (var bit in bits)
{
bitString += (bool)bit ? "1" : "0";
}
Console.WriteLine(bitString);
// from string:
string longBitString = "01000101001001010100010010010";
var longIntArray = longBitString.ToCharArray().Select(p => p.Equals('0') ? false : true).ToArray();
var longBitArray = new BitArray(longIntArray);

finding an string expression in an sentence

I have like a three word expression: "Shut The Door" and I want to find it in a sentence. Since They are kind of seperated by space what would be the best solution for it.

If you have the string:
string sample = "If you know what's good for you, you'll shut the door!";
And you want to find where it is in a sentence, you can use the IndexOf method.
int index = sample.IndexOf("shut the door");
// index will be 42
A non -1 answer means the string has been located. -1 means it does not exist in the string. Please note that the search string ("shut the door") is case sensitive.

Use build in Regex.Match Method for matching strings.
string text = "One car red car blue car";
string pat = #"(\w+)\s+(car)";
// Compile the regular expression.
Regex r = new Regex(pat, RegexOptions.IgnoreCase);
// Match the regular expression pattern against a text string.
Match m = r.Match(text);
int matchCount = 0;
while (m.Success)
{
Console.WriteLine("Match"+ (++matchCount));
for (int i = 1; i <= 2; i++)
{
Group g = m.Groups[i];
Console.WriteLine("Group"+i+"='" + g + "'");
CaptureCollection cc = g.Captures;
for (int j = 0; j < cc.Count; j++)
{
Capture c = cc[j];
System.Console.WriteLine("Capture"+j+"='" + c + "', Position="+c.Index);
}
}
m = m.NextMatch();
}
http://msdn.microsoft.com/en-us/library/system.text.regularexpressions.regex.match(v=vs.71).aspx
http://support.microsoft.com/kb/308252

if (string1.indexOf(string2) >= 0)
...

The spaces are nothing special, they are just characters, so you can find a string like this like yuo would find any other string in your sentence, for example using "indexOf" if you need the position, or just "Contains" if you need to know if it exists or not.
E.g.
string sentence = "foo bar baz";
string phrase = "bar baz";
Console.WriteLine(sentence.Contains(phrase)); // True

Here is some C# code to find a substrings using a start string and end string point but you can use as a base and modify (i.e. remove need for end string) to just find your string...
2 versions, one to just find the first instance of a substring, other returns a dictionary of all starting positions of the substring and the actual string.
public Dictionary<int, string> GetSubstringDic(string start, string end, string source, bool includeStartEnd, bool caseInsensitive)
{
int startIndex = -1;
int endIndex = -1;
int length = -1;
int sourceLength = source.Length;
Dictionary<int, string> result = new Dictionary<int, string>();
try
{
//if just want to find string, case insensitive
if (caseInsensitive)
{
source = source.ToLower();
start = start.ToLower();
end = end.ToLower();
}
//does start string exist
startIndex = source.IndexOf(start);
if (startIndex != -1)
{
//start to check for each instance of matches for the length of the source string
while (startIndex < sourceLength && startIndex > -1)
{
//does end string exist?
endIndex = source.IndexOf(end, startIndex + 1);
if (endIndex != -1)
{
//if we want to get length of string including the start and end strings
if (includeStartEnd)
{
//make sure to include the end string
length = (endIndex + end.Length) - startIndex;
}
else
{
//change start index to not include the start string
startIndex = startIndex + start.Length;
length = endIndex - startIndex;
}
//add to dictionary
result.Add(startIndex, source.Substring(startIndex, length));
//move start position up
startIndex = source.IndexOf(start, endIndex + 1);
}
else
{
//no end so break out of while;
break;
}
}
}
}
catch (Exception ex)
{
//Notify of Error
result = new Dictionary<int, string>();
StringBuilder g_Error = new StringBuilder();
g_Error.AppendLine("GetSubstringDic: " + ex.Message.ToString());
g_Error.AppendLine(ex.StackTrace.ToString());
}
return result;
}
public string GetSubstring(string start, string end, string source, bool includeStartEnd, bool caseInsensitive)
{
int startIndex = -1;
int endIndex = -1;
int length = -1;
int sourceLength = source.Length;
string result = string.Empty;
try
{
if (caseInsensitive)
{
source = source.ToLower();
start = start.ToLower();
end = end.ToLower();
}
startIndex = source.IndexOf(start);
if (startIndex != -1)
{
endIndex = source.IndexOf(end, startIndex + 1);
if (endIndex != -1)
{
if (includeStartEnd)
{
length = (endIndex + end.Length) - startIndex;
}
else
{
startIndex = startIndex + start.Length;
length = endIndex - startIndex;
}
result = source.Substring(startIndex, length);
}
}
}
catch (Exception ex)
{
//Notify of Error
result = string.Empty;
StringBuilder g_Error = new StringBuilder();
g_Error.AppendLine("GetSubstring: " + ex.Message.ToString());
g_Error.AppendLine(ex.StackTrace.ToString());
}
return result;
}

You may want to make sure the check ignores the case of both phrases.
string theSentence = "I really want you to shut the door.";
string thePhrase = "Shut The Door";
bool phraseIsPresent = theSentence.ToUpper().Contains(thePhrase.ToUpper());
int phraseStartsAt = theSentence.IndexOf(
thePhrase,
StringComparison.InvariantCultureIgnoreCase);
Console.WriteLine("Is the phrase present? " + phraseIsPresent);
Console.WriteLine("The phrase starts at character: " + phraseStartsAt);
This outputs:
Is the phrase present? True
The phrase starts at character: 21