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Split a string if delimiter is between single quotes [duplicate]

This question already has answers here:
How to split csv whose columns may contain comma
(9 answers)
Closed 4 years ago.
I have the following comma-separated string that I need to split. The problem is that some of the content is within quotes and contains commas that shouldn't be used in the split.
String:
111,222,"33,44,55",666,"77,88","99"
I want the output:
111
222
33,44,55
666
77,88
99
I have tried this:
(?:,?)((?<=")[^"]+(?=")|[^",]+)
But it reads the comma between "77,88","99" as a hit and I get the following output:
111
222
33,44,55
666
77,88
,
99

Depending on your needs you may not be able to use a csv parser, and may in fact want to re-invent the wheel!!
You can do so with some simple regex
(?:^|,)(\"(?:[^\"]+|\"\")*\"|[^,]*)
This will do the following:
(?:^|,) = Match expression "Beginning of line or string ,"
(\"(?:[^\"]+|\"\")*\"|[^,]*) = A numbered capture group, this will select between 2 alternatives:
stuff in quotes
stuff between commas
This should give you the output you are looking for.
Example code in C#
static Regex csvSplit = new Regex("(?:^|,)(\"(?:[^\"]+|\"\")*\"|[^,]*)", RegexOptions.Compiled);
public static string[] SplitCSV(string input)
{
List<string> list = new List<string>();
string curr = null;
foreach (Match match in csvSplit.Matches(input))
{
curr = match.Value;
if (0 == curr.Length)
{
list.Add("");
}
list.Add(curr.TrimStart(','));
}
return list.ToArray();
}
private void button1_Click(object sender, RoutedEventArgs e)
{
Console.WriteLine(SplitCSV("111,222,\"33,44,55\",666,\"77,88\",\"99\""));
}
Warning As per #MrE's comment - if a rogue new line character appears in a badly formed csv file and you end up with an uneven ("string) you'll get catastrophic backtracking (https://www.regular-expressions.info/catastrophic.html) in your regex and your system will likely crash (like our production system did). Can easily be replicated in Visual Studio and as I've discovered will crash it. A simple try/catch will not trap this issue either.
You should use:
(?:^|,)(\"(?:[^\"])*\"|[^,]*)
instead

Fast and easy:
public static string[] SplitCsv(string line)
{
List<string> result = new List<string>();
StringBuilder currentStr = new StringBuilder("");
bool inQuotes = false;
for (int i = 0; i < line.Length; i++) // For each character
{
if (line[i] == '\"') // Quotes are closing or opening
inQuotes = !inQuotes;
else if (line[i] == ',') // Comma
{
if (!inQuotes) // If not in quotes, end of current string, add it to result
{
result.Add(currentStr.ToString());
currentStr.Clear();
}
else
currentStr.Append(line[i]); // If in quotes, just add it
}
else // Add any other character to current string
currentStr.Append(line[i]);
}
result.Add(currentStr.ToString());
return result.ToArray(); // Return array of all strings
}
With this string as input :
111,222,"33,44,55",666,"77,88","99"
It will return :
111
222
33,44,55
666
77,88
99

i really like jimplode's answer, but I think a version with yield return is a little bit more useful, so here it is:
public IEnumerable<string> SplitCSV(string input)
{
Regex csvSplit = new Regex("(?:^|,)(\"(?:[^\"]+|\"\")*\"|[^,]*)", RegexOptions.Compiled);
foreach (Match match in csvSplit.Matches(input))
{
yield return match.Value.TrimStart(',');
}
}
Maybe it's even more useful to have it like an extension method:
public static class StringHelper
{
public static IEnumerable<string> SplitCSV(this string input)
{
Regex csvSplit = new Regex("(?:^|,)(\"(?:[^\"]+|\"\")*\"|[^,]*)", RegexOptions.Compiled);
foreach (Match match in csvSplit.Matches(input))
{
yield return match.Value.TrimStart(',');
}
}
}

This regular expression works without the need to loop through values and TrimStart(','), like in the accepted answer:
((?<=\")[^\"]*(?=\"(,|$)+)|(?<=,|^)[^,\"]*(?=,|$))
Here is the implementation in C#:
string values = "111,222,\"33,44,55\",666,\"77,88\",\"99\"";
MatchCollection matches = new Regex("((?<=\")[^\"]*(?=\"(,|$)+)|(?<=,|^)[^,\"]*(?=,|$))").Matches(values);
foreach (var match in matches)
{
Console.WriteLine(match);
}
Outputs
111
222
33,44,55
666
77,88
99

None of these answers work when the string has a comma inside quotes, as in "value, 1", or escaped double-quotes, as in "value ""1""", which are valid CSV that should be parsed as value, 1 and value "1", respectively.
This will also work with the tab-delimited format if you pass in a tab instead of a comma as your delimiter.
public static IEnumerable<string> SplitRow(string row, char delimiter = ',')
{
var currentString = new StringBuilder();
var inQuotes = false;
var quoteIsEscaped = false; //Store when a quote has been escaped.
row = string.Format("{0}{1}", row, delimiter); //We add new cells at the delimiter, so append one for the parser.
foreach (var character in row.Select((val, index) => new {val, index}))
{
if (character.val == delimiter) //We hit a delimiter character...
{
if (!inQuotes) //Are we inside quotes? If not, we've hit the end of a cell value.
{
Console.WriteLine(currentString);
yield return currentString.ToString();
currentString.Clear();
}
else
{
currentString.Append(character.val);
}
} else {
if (character.val != ' ')
{
if(character.val == '"') //If we've hit a quote character...
{
if(character.val == '\"' && inQuotes) //Does it appear to be a closing quote?
{
if (row[character.index + 1] == character.val) //If the character afterwards is also a quote, this is to escape that (not a closing quote).
{
quoteIsEscaped = true; //Flag that we are escaped for the next character. Don't add the escaping quote.
}
else if (quoteIsEscaped)
{
quoteIsEscaped = false; //This is an escaped quote. Add it and revert quoteIsEscaped to false.
currentString.Append(character.val);
}
else
{
inQuotes = false;
}
}
else
{
if (!inQuotes)
{
inQuotes = true;
}
else
{
currentString.Append(character.val); //...It's a quote inside a quote.
}
}
}
else
{
currentString.Append(character.val);
}
}
else
{
if (!string.IsNullOrWhiteSpace(currentString.ToString())) //Append only if not new cell
{
currentString.Append(character.val);
}
}
}
}
}

With minor updates to the function provided by "Chad Hedgcock".
Updates are on:
Line 26: character.val == '\"' - This can never be true due to the check made on Line 24. i.e. character.val == '"'
Line 28: if (row[character.index + 1] == character.val) added !quoteIsEscaped to escape 3 consecutive quotes.
public static IEnumerable<string> SplitRow(string row, char delimiter = ',')
{
var currentString = new StringBuilder();
var inQuotes = false;
var quoteIsEscaped = false; //Store when a quote has been escaped.
row = string.Format("{0}{1}", row, delimiter); //We add new cells at the delimiter, so append one for the parser.
foreach (var character in row.Select((val, index) => new {val, index}))
{
if (character.val == delimiter) //We hit a delimiter character...
{
if (!inQuotes) //Are we inside quotes? If not, we've hit the end of a cell value.
{
//Console.WriteLine(currentString);
yield return currentString.ToString();
currentString.Clear();
}
else
{
currentString.Append(character.val);
}
} else {
if (character.val != ' ')
{
if(character.val == '"') //If we've hit a quote character...
{
if(character.val == '"' && inQuotes) //Does it appear to be a closing quote?
{
if (row[character.index + 1] == character.val && !quoteIsEscaped) //If the character afterwards is also a quote, this is to escape that (not a closing quote).
{
quoteIsEscaped = true; //Flag that we are escaped for the next character. Don't add the escaping quote.
}
else if (quoteIsEscaped)
{
quoteIsEscaped = false; //This is an escaped quote. Add it and revert quoteIsEscaped to false.
currentString.Append(character.val);
}
else
{
inQuotes = false;
}
}
else
{
if (!inQuotes)
{
inQuotes = true;
}
else
{
currentString.Append(character.val); //...It's a quote inside a quote.
}
}
}
else
{
currentString.Append(character.val);
}
}
else
{
if (!string.IsNullOrWhiteSpace(currentString.ToString())) //Append only if not new cell
{
currentString.Append(character.val);
}
}
}
}
}

For Jay's answer, if you use a 2nd boolean then you can have nested double-quotes inside single-quotes and vice-versa.
private string[] splitString(string stringToSplit)
{
char[] characters = stringToSplit.ToCharArray();
List<string> returnValueList = new List<string>();
string tempString = "";
bool blockUntilEndQuote = false;
bool blockUntilEndQuote2 = false;
int characterCount = 0;
foreach (char character in characters)
{
characterCount = characterCount + 1;
if (character == '"' && !blockUntilEndQuote2)
{
if (blockUntilEndQuote == false)
{
blockUntilEndQuote = true;
}
else if (blockUntilEndQuote == true)
{
blockUntilEndQuote = false;
}
}
if (character == '\'' && !blockUntilEndQuote)
{
if (blockUntilEndQuote2 == false)
{
blockUntilEndQuote2 = true;
}
else if (blockUntilEndQuote2 == true)
{
blockUntilEndQuote2 = false;
}
}
if (character != ',')
{
tempString = tempString + character;
}
else if (character == ',' && (blockUntilEndQuote == true || blockUntilEndQuote2 == true))
{
tempString = tempString + character;
}
else
{
returnValueList.Add(tempString);
tempString = "";
}
if (characterCount == characters.Length)
{
returnValueList.Add(tempString);
tempString = "";
}
}
string[] returnValue = returnValueList.ToArray();
return returnValue;
}

The original version
Currently I use the following regex:
public static Regex regexCSVSplit = new Regex(#"(?x:(
(?<FULL>
(^|[,;\t\r\n])\s*
( (?<QUODAT> (?<QUO>[""'])(?<DAT>([^,;\t\r\n]|(?<!\k<QUO>\s*)[,;\t\r\n])*)\k<QUO>) |
(?<QUODAT> (?<DAT> [^""',;\s\r\n]* )) )
(?=\s*([,;\t\r\n]|$))
) |
(?<FULL>
(^|[\s\t\r\n])
( (?<QUODAT> (?<QUO>[""'])(?<DAT> [^""',;\s\t\r\n]* )\k<QUO>) |
(?<QUODAT> (?<DAT> [^""',;\s\t\r\n]* )) )
(?=[,;\s\t\r\n]|$)
)
))", RegexOptions.Compiled);
This solution can handle pretty chaotic cases too like below:
This is how to feed the result into an array:
var data = regexCSVSplit.Matches(line_to_process).Cast<Match>().
Select(x => x.Groups["DAT"].Value).ToArray();
See this example in action HERE
Note: The regular expression contains two set of <FULL> block and each of them contains two <QUODAT> block separated by "or" (|). Depending on your task you may only need one of them.
Note: That this regular expression gives us one string array, and works on single line with or without <carrier return> and/or <line feed>.
Simplified version
The following regular expression will already cover many complex cases:
public static Regex regexCSVSplit = new Regex(#"(?x:(
(?<FULL>
(^|[,;\t\r\n])\s*
(?<QUODAT> (?<QUO>[""'])(?<DAT>([^,;\t\r\n]|(?<!\k<QUO>\s*)[,;\t\r\n])*)\k<QUO>)
(?=\s*([,;\t\r\n]|$))
)
))", RegexOptions.Compiled);
See this example in action: HERE
It can process complex, easy and empty items too:
This is how to feed the result into an array:
var data = regexCSVSplit.Matches(line_to_process).Cast<Match>().
Select(x => x.Groups["DAT"].Value).ToArray();
The main rule here is that every item may contain anything but the <quotation mark><separators><comma> sequence AND each item shall being and end with the same <quotation mark>.
<quotation mark>: <">, <'>
<comma>: <,>, <;>, <tab>, <carrier return>, <line feed>
Edit notes: I added some more explanation to make it easier to understand and replaces the text "CO" with "QUO".

Try this:
string s = #"111,222,""33,44,55"",666,""77,88"",""99""";
List<string> result = new List<string>();
var splitted = s.Split('"').ToList<string>();
splitted.RemoveAll(x => x == ",");
foreach (var it in splitted)
{
if (it.StartsWith(",") || it.EndsWith(","))
{
var tmp = it.TrimEnd(',').TrimStart(',');
result.AddRange(tmp.Split(','));
}
else
{
if(!string.IsNullOrEmpty(it)) result.Add(it);
}
}
//Results:
foreach (var it in result)
{
Console.WriteLine(it);
}

I know I'm a bit late to this, but for searches, here is how I did what you are asking about in C sharp
private string[] splitString(string stringToSplit)
{
char[] characters = stringToSplit.ToCharArray();
List<string> returnValueList = new List<string>();
string tempString = "";
bool blockUntilEndQuote = false;
int characterCount = 0;
foreach (char character in characters)
{
characterCount = characterCount + 1;
if (character == '"')
{
if (blockUntilEndQuote == false)
{
blockUntilEndQuote = true;
}
else if (blockUntilEndQuote == true)
{
blockUntilEndQuote = false;
}
}
if (character != ',')
{
tempString = tempString + character;
}
else if (character == ',' && blockUntilEndQuote == true)
{
tempString = tempString + character;
}
else
{
returnValueList.Add(tempString);
tempString = "";
}
if (characterCount == characters.Length)
{
returnValueList.Add(tempString);
tempString = "";
}
}
string[] returnValue = returnValueList.ToArray();
return returnValue;
}

Don't reinvent a CSV parser, try FileHelpers.

I needed something a little more robust, so I took from here and created this... This solution is a little less elegant and a little more verbose, but in my testing (with a 1,000,000 row sample), I found this to be 2 to 3 times faster. Plus it handles non-escaped, embedded quotes. I used string delimiter and qualifiers instead of chars because of the requirements of my solution. I found it more difficult than I expected to find a good, generic CSV parser so I hope this parsing algorithm can help someone.
public static string[] SplitRow(string record, string delimiter, string qualifier, bool trimData)
{
// In-Line for example, but I implemented as string extender in production code
Func <string, int, int> IndexOfNextNonWhiteSpaceChar = delegate (string source, int startIndex)
{
if (startIndex >= 0)
{
if (source != null)
{
for (int i = startIndex; i < source.Length; i++)
{
if (!char.IsWhiteSpace(source[i]))
{
return i;
}
}
}
}
return -1;
};
var results = new List<string>();
var result = new StringBuilder();
var inQualifier = false;
var inField = false;
// We add new columns at the delimiter, so append one for the parser.
var row = $"{record}{delimiter}";
for (var idx = 0; idx < row.Length; idx++)
{
// A delimiter character...
if (row[idx]== delimiter[0])
{
// Are we inside qualifier? If not, we've hit the end of a column value.
if (!inQualifier)
{
results.Add(trimData ? result.ToString().Trim() : result.ToString());
result.Clear();
inField = false;
}
else
{
result.Append(row[idx]);
}
}
// NOT a delimiter character...
else
{
// ...Not a space character
if (row[idx] != ' ')
{
// A qualifier character...
if (row[idx] == qualifier[0])
{
// Qualifier is closing qualifier...
if (inQualifier && row[IndexOfNextNonWhiteSpaceChar(row, idx + 1)] == delimiter[0])
{
inQualifier = false;
continue;
}
else
{
// ...Qualifier is opening qualifier
if (!inQualifier)
{
inQualifier = true;
}
// ...It's a qualifier inside a qualifier.
else
{
inField = true;
result.Append(row[idx]);
}
}
}
// Not a qualifier character...
else
{
result.Append(row[idx]);
inField = true;
}
}
// ...A space character
else
{
if (inQualifier || inField)
{
result.Append(row[idx]);
}
}
}
}
return results.ToArray<string>();
}
Some test code:
//var input = "111,222,\"33,44,55\",666,\"77,88\",\"99\"";
var input =
"111, 222, \"99\",\"33,44,55\" , \"666 \"mark of a man\"\", \" spaces \"77,88\" \"";
Console.WriteLine("Split with trim");
Console.WriteLine("---------------");
var result = SplitRow(input, ",", "\"", true);
foreach (var r in result)
{
Console.WriteLine(r);
}
Console.WriteLine("");
// Split 2
Console.WriteLine("Split with no trim");
Console.WriteLine("------------------");
var result2 = SplitRow(input, ",", "\"", false);
foreach (var r in result2)
{
Console.WriteLine(r);
}
Console.WriteLine("");
// Time Trial 1
Console.WriteLine("Experimental Process (1,000,000) iterations");
Console.WriteLine("-------------------------------------------");
watch = Stopwatch.StartNew();
for (var i = 0; i < 1000000; i++)
{
var x1 = SplitRow(input, ",", "\"", false);
}
watch.Stop();
elapsedMs = watch.ElapsedMilliseconds;
Console.WriteLine($"Total Process Time: {string.Format("{0:0.###}", elapsedMs / 1000.0)} Seconds");
Console.WriteLine("");
Results
Split with trim
---------------
111
222
99
33,44,55
666 "mark of a man"
spaces "77,88"
Split with no trim
------------------
111
222
99
33,44,55
666 "mark of a man"
spaces "77,88"
Original Process (1,000,000) iterations
-------------------------------
Total Process Time: 7.538 Seconds
Experimental Process (1,000,000) iterations
--------------------------------------------
Total Process Time: 3.363 Seconds

I once had to do something similar and in the end I got stuck with Regular Expressions. The inability for Regex to have state makes it pretty tricky - I just ended up writing a simple little parser.
If you're doing CSV parsing you should just stick to using a CSV parser - don't reinvent the wheel.

Here is my fastest implementation based upon string raw pointer manipulation:
string[] FastSplit(string sText, char? cSeparator = null, char? cQuotes = null)
{
string[] oTokens;
if (null == cSeparator)
{
cSeparator = DEFAULT_PARSEFIELDS_SEPARATOR;
}
if (null == cQuotes)
{
cQuotes = DEFAULT_PARSEFIELDS_QUOTE;
}
unsafe
{
fixed (char* lpText = sText)
{
#region Fast array estimatation
char* lpCurrent = lpText;
int nEstimatedSize = 0;
while (0 != *lpCurrent)
{
if (cSeparator == *lpCurrent)
{
nEstimatedSize++;
}
lpCurrent++;
}
nEstimatedSize++; // Add EOL char(s)
string[] oEstimatedTokens = new string[nEstimatedSize];
#endregion
#region Parsing
char[] oBuffer = new char[sText.Length];
int nIndex = 0;
int nTokens = 0;
lpCurrent = lpText;
while (0 != *lpCurrent)
{
if (cQuotes == *lpCurrent)
{
// Quotes parsing
lpCurrent++; // Skip quote
nIndex = 0; // Reset buffer
while (
(0 != *lpCurrent)
&& (cQuotes != *lpCurrent)
)
{
oBuffer[nIndex] = *lpCurrent; // Store char
lpCurrent++; // Move source cursor
nIndex++; // Move target cursor
}
}
else if (cSeparator == *lpCurrent)
{
// Separator char parsing
oEstimatedTokens[nTokens++] = new string(oBuffer, 0, nIndex); // Store token
nIndex = 0; // Skip separator and Reset buffer
}
else
{
// Content parsing
oBuffer[nIndex] = *lpCurrent; // Store char
nIndex++; // Move target cursor
}
lpCurrent++; // Move source cursor
}
// Recover pending buffer
if (nIndex > 0)
{
// Store token
oEstimatedTokens[nTokens++] = new string(oBuffer, 0, nIndex);
}
// Build final tokens list
if (nTokens == nEstimatedSize)
{
oTokens = oEstimatedTokens;
}
else
{
oTokens = new string[nTokens];
Array.Copy(oEstimatedTokens, 0, oTokens, 0, nTokens);
}
#endregion
}
}
// Epilogue
return oTokens;
}

Try this
private string[] GetCommaSeperatedWords(string sep, string line)
{
List<string> list = new List<string>();
StringBuilder word = new StringBuilder();
int doubleQuoteCount = 0;
for (int i = 0; i < line.Length; i++)
{
string chr = line[i].ToString();
if (chr == "\"")
{
if (doubleQuoteCount == 0)
doubleQuoteCount++;
else
doubleQuoteCount--;
continue;
}
if (chr == sep && doubleQuoteCount == 0)
{
list.Add(word.ToString());
word = new StringBuilder();
continue;
}
word.Append(chr);
}
list.Add(word.ToString());
return list.ToArray();
}

This is Chad's answer rewritten with state based logic. His answered failed for me when it came across """BRAD""" as a field. That should return "BRAD" but it just ate up all the remaining fields. When I tried to debug it I just ended up rewriting it as state based logic:
enum SplitState { s_begin, s_infield, s_inquotefield, s_foundquoteinfield };
public static IEnumerable<string> SplitRow(string row, char delimiter = ',')
{
var currentString = new StringBuilder();
SplitState state = SplitState.s_begin;
row = string.Format("{0}{1}", row, delimiter); //We add new cells at the delimiter, so append one for the parser.
foreach (var character in row.Select((val, index) => new { val, index }))
{
//Console.WriteLine("character = " + character.val + " state = " + state);
switch (state)
{
case SplitState.s_begin:
if (character.val == delimiter)
{
/* empty field */
yield return currentString.ToString();
currentString.Clear();
} else if (character.val == '"')
{
state = SplitState.s_inquotefield;
} else
{
currentString.Append(character.val);
state = SplitState.s_infield;
}
break;
case SplitState.s_infield:
if (character.val == delimiter)
{
/* field with data */
yield return currentString.ToString();
state = SplitState.s_begin;
currentString.Clear();
} else
{
currentString.Append(character.val);
}
break;
case SplitState.s_inquotefield:
if (character.val == '"')
{
// could be end of field, or escaped quote.
state = SplitState.s_foundquoteinfield;
} else
{
currentString.Append(character.val);
}
break;
case SplitState.s_foundquoteinfield:
if (character.val == '"')
{
// found escaped quote.
currentString.Append(character.val);
state = SplitState.s_inquotefield;
}
else if (character.val == delimiter)
{
// must have been last quote so we must find delimiter
yield return currentString.ToString();
state = SplitState.s_begin;
currentString.Clear();
}
else
{
throw new Exception("Quoted field not terminated.");
}
break;
default:
throw new Exception("unknown state:" + state);
}
}
//Console.WriteLine("currentstring = " + currentString.ToString());
}
This is a lot more lines of code than the other solutions, but it is easy to modify to add edge cases.

LINQ instead of for loop in wpf?

I am working with the WPF RichTextbox. I have to get all the lines in the RichTextbox. So I am using a for loop to get all the lines, but the RichTextbox contains a large text content. It takes too much time.
So how do I get around a 1000 line loop in less time?
I've tried parallel.for but it gives an exception as it tries to get each line of the RichTextbox text.
Here is my code.
for (Int32 icnt = 0; icnt <= iLineCount; icnt++)
{
LineDetails lnDtls = new LineDetails();
lnDtls.LineText = GetLineText(txtAppendValue.CaretPosition.GetLineStartPosition(icnt));
iCurrentEnd = iCurrentEnd + lnDtls.LineText.Length;
lnDtls.LineLength = iCurrentEnd;
listLines.Add(lnDtls);
}
GetLineText():
String GetLineText(TextPointer TextPointer)
{
tp1 = TextPointer.GetLineStartPosition(0);
if (tp1 == null)
{
return null;
}
else
{
tpNextLine2 = tp1.GetLineStartPosition(1);
if (tr != null)
{
tr = null;
}
if (tpNextLine2 == null)
{
tpNextLine2 = txtAppendValue.Document.ContentEnd;
}
tr = new TextRange(tp1, tpNextLine2);
return tr.Text;
}
}
So can I use LINQ instead of for loop for fast execution?

I don't see why it needs to be this complicated. A few simple line of code would give you all the lines in a rich text box.
string text = new TextRange(richTextBox.Document.ContentStart, richTextBox.Document.ContentEnd).Text;
text.Replace("\r\n", "\n");
var lines = text.Split(new char[] {'\n'});

Problems changing color to a selected text in a richtextbox

I have this code and it's applied to a form. For every word in the richtextbox it looks if it's present in a txt file that i'm using as a dictionary and if not it changes the color of that word to red. I know the code opens and closes the stream for every word and I'm fixing that soon.
private void sottolinea_errori_Click(object sender, EventArgs e)
{
string line;
string[] linea = TextBox_stampa_contenuto.Lines;
if (TextBox_stampa_contenuto.Text != "")
{
foreach (string k in linea)
{
string[] parole = k.Split(new Char[] { ' ', ',', '.', ':', '\t' });
foreach (string s in parole)
{
Regex rgx = new Regex(#"\d");
if (!rgx.IsMatch(s))
{
if (s.Trim() != "")
{
s.Trim();
string path = #"280000parole.txt";
bool esito = true;
StreamReader file = new StreamReader(path);
while ((line = file.ReadLine()) != null && esito == true)
if (string.Compare(line, s) == 0)
esito = false; // i put this false when I find the word in the dictionary file
file.Close();
if (esito) //if true means that the word wasn't found
{
int inizioParola=0, indice; //indice means index, inizio parola is for selectionStart
while ((indice = TextBox_stampa_contenuto.Text.IndexOf(s, inizioParola)) != -1)
{
TextBox_stampa_contenuto.Select(indice, s.Length);
inizioParola = indice + s.Length;
}
TextBox_stampa_contenuto.SelectionStart = inizioParola - s.Length;
TextBox_stampa_contenuto.SelectionLength = s.Length;
TextBox_stampa_contenuto.SelectionColor = Color.Red;
}
TextBox_stampa_contenuto.SelectionLength = 0;
}
}
}
}
}
}
The problems are:
If the first words of the file are the same it changes the color of the last one only
If the last word it's wrong the new text that you input it's going to be red
How can I underline the wrong words like bad spelling from Word?
If you can help me I'll really appreciate!

Here is a working example, added caching of the words so you don't read the file each time, trimmed all the words, put all the words to lower case and optimized the logic. I have added the comments to make the code easy to read and understand.
WordList.txt Contains
Apple
Banana
Computer
private void sottolinea_errori_Click(object sender, EventArgs e)
{
// Get all the lines in the rich text box
string[] textBoxLines = this.TextBox_stampa_contenuto.Lines;
// Check that there is some text
if (this.TextBox_stampa_contenuto.Text != string.Empty)
{
// Create a regular expression match
Regex rgx = new Regex(#"\d");
// Create a new dictionary to hold all the words
Dictionary<string, int> wordDictionary = new Dictionary<string, int>();
// Path to the list of words
const string WordListPath = #"WordList.txt";
// Open the file and read all the words
StreamReader file = new StreamReader(WordListPath);
// Read each file into the dictionary
int i = 0;
while (!file.EndOfStream)
{
// Read each word, one word per line
string line = file.ReadLine();
// Check if the line is empty or null and not in the dictionary
if (!string.IsNullOrEmpty(line) && !wordDictionary.ContainsKey(line))
{
// Add the word to the dictionary for easy lookup add the word to lower case
wordDictionary.Add(line.ToLower(), i);
// Incrament the counter
i++;
}
}
// Close the file
file.Close();
// For each line in the text box loop over the logic
foreach (string textLine in textBoxLines)
{
// Split the text line so we get individual words, remove empty entries and trim all the words
string[] words = textLine.Split(new char[] { ' ', ',', '.', ':', '\t' }, StringSplitOptions.RemoveEmptyEntries).Select(p => p.Trim().ToLower()).ToArray();
// For each word that does not contain a digit
foreach (string word in words.Where(x => !rgx.IsMatch(x)))
{
// Check if the word is found, returns true if found
if (!wordDictionary.ContainsKey(word))
{
// Initialize the text modification variables
int wordStartPosition, seachIndex = 0;
// Find all instances of the current word
while ((wordStartPosition = this.TextBox_stampa_contenuto.Text.IndexOf(word, seachIndex, StringComparison.InvariantCultureIgnoreCase)) != -1)
{
// Select the word in the text box
this.TextBox_stampa_contenuto.Select(wordStartPosition, word.Length);
// Set the selection color
this.TextBox_stampa_contenuto.SelectionColor = Color.Red;
// Increase the search index after the word
seachIndex = wordStartPosition + word.Length;
}
}
}
}
}
}

c# search string in txt file

I want to find a string in a txt file if string compares, it should go on reading lines till another string which I'm using as parameter.
Example:
CustomerEN //search for this string
...
some text which has details about the customer
id "123456"
username "rootuser"
...
CustomerCh //get text till this string
I need the details to work with them otherwise.
I'm using linq to search for "CustomerEN" like this:
File.ReadLines(pathToTextFile).Any(line => line.Contains("CustomerEN"))
But now I'm stuck with reading lines (data) till "CustomerCh" to extract details.

If your pair of lines will only appear once in your file, you could use
File.ReadLines(pathToTextFile)
.SkipWhile(line => !line.Contains("CustomerEN"))
.Skip(1) // optional
.TakeWhile(line => !line.Contains("CustomerCh"));
If you could have multiple occurrences in one file, you're probably better off using a regular foreach loop - reading lines, keeping track of whether you're currently inside or outside a customer etc:
List<List<string>> groups = new List<List<string>>();
List<string> current = null;
foreach (var line in File.ReadAllLines(pathToFile))
{
if (line.Contains("CustomerEN") && current == null)
current = new List<string>();
else if (line.Contains("CustomerCh") && current != null)
{
groups.Add(current);
current = null;
}
if (current != null)
current.Add(line);
}

You have to use while since foreach does not know about index. Below is an example code.
int counter = 0;
string line;
Console.Write("Input your search text: ");
var text = Console.ReadLine();
System.IO.StreamReader file =
new System.IO.StreamReader("SampleInput1.txt");
while ((line = file.ReadLine()) != null)
{
if (line.Contains(text))
{
break;
}
counter++;
}
Console.WriteLine("Line number: {0}", counter);
file.Close();
Console.ReadLine();

With LINQ, you could use the SkipWhile / TakeWhile methods, like this:
var importantLines =
File.ReadLines(pathToTextFile)
.SkipWhile(line => !line.Contains("CustomerEN"))
.TakeWhile(line => !line.Contains("CustomerCh"));

If you whant only one first string, you can use simple for-loop.
var lines = File.ReadAllLines(pathToTextFile);
var firstFound = false;
for(int index = 0; index < lines.Count; index++)
{
if(!firstFound && lines[index].Contains("CustomerEN"))
{
firstFound = true;
}
if(firstFound && lines[index].Contains("CustomerCh"))
{
//do, what you want, and exit the loop
// return lines[index];
}
}

I worked a little bit the method that Rawling posted here to find more than one line in the same file until the end. This is what worked for me:
foreach (var line in File.ReadLines(pathToFile))
{
if (line.Contains("CustomerEN") && current == null)
{
current = new List<string>();
current.Add(line);
}
else if (line.Contains("CustomerEN") && current != null)
{
current.Add(line);
}
}
string s = String.Join(",", current);
MessageBox.Show(s);

Highlighting User Defined Keywords in RichTextBox

I am searching XML files to see if there are contents which match the words inserted in these textboxes txtComKeyword1, txtComKeyword2, txtComKeyword3 and/or txtComKeyword4. The function below is working, but may I know how can I highlight the keywords that user entered in the four textboxes that match that appear in my richComResults richtextbox?
For example, my user will fill in those four textboxes ie. txtComKeyword1, txtComKeyword2, txtComKeyword3 and txtComKeyword4. Then, my code will parse the XML file to see if the nodes contain these four keywords, if yes, the nodes' data will be output on my richComResults, I wanna highlight those four keywords (eg txtComKeyword1=hello, txtComKeyword2=bye, txtComKeyword3=morning, txtComKeyword4=night). These 4 words, if found and appear in richComResults, will be highlighted with color.
I have no clue after searching for a while, my case is much different from other questions. I am a newbie in programming, your help would be much appreciated. Thank you!
My Code:
private void searchComByKeywords()
{
// Process the list of files found in the directory.
string[] fileEntries = Directory.GetFiles(sourceDir);
foreach (string fileName in fileEntries)
{
XmlDocument xmlDoc = new XmlDocument(); //* create an xml document object.
string docPath = fileName;
xmlDoc.Load(docPath); //* load the XML document from the specified file.
XmlNodeList nodeList = xmlDoc.GetElementsByTagName("item");
foreach (XmlNode node in nodeList)
{
XmlElement itemElement = (XmlElement) node;
string itemDescription = itemElement.GetElementsByTagName("description")[0].InnerText;
if (txtComKeyword1.Text != (String.Empty) && itemDescription.ToLower().Contains(txtComKeyword1.Text.ToLower()) ||
txtComKeyword2.Text != (String.Empty) && itemDescription.ToLower().Contains(txtComKeyword2.Text.ToString()) ||
txtComKeyword3.Text != (String.Empty) && itemDescription.ToLower().Contains(txtComKeyword3.Text.ToString()) ||
txtComKeyword4.Text != (String.Empty) && itemDescription.ToLower().Contains(txtComKeyword4.Text.ToString()))
{
string itemTitle = itemElement.GetElementsByTagName("title")[0].InnerText;
string itemDate = itemElement.GetElementsByTagName("pubDate")[0].InnerText;
string itemAuthor = itemElement.GetElementsByTagName("author")[0].InnerText;
richComResults.AppendText("Author: " + itemAuthor + "\nDate: " + itemDate + "\nTitle: " + itemTitle + "\nDescription: " + itemDescription + "\n\n--------\n\n");
}
}
}
}

Try this:
int pointer = 0;
int index = 0;
string keyword = "txtComKeyword1";
while (true)
{
index = richComResults.Text.IndexOf(keyword, pointer);
//if keyword not found
if (index == -1)
{
break;
}
richComResults.Select(index, keyword.Length);
richComResults.SelectionFont = new System.Drawing.Font(richComResults.Font, FontStyle.Bold);
pointer = index + keyword.Length;
}
This searches for the keyword and highlights it. Then it continues the search after the found keyword. The pointer is used to keep track of the search position in your text. The index marks the position of the found keyword.

Jan's answer contains great content, but I shuddered mildly at the while(true) and break aspect! Here's my tweaked (case-insensitive) version...
int nextHigh = RTF.Text.IndexOf(txSearch, 0, StringComparison.OrdinalIgnoreCase);
while (nextHigh >= 0)
{
RTF.Select(nextHigh, txSearch.Length);
RTF.SelectionColor = Color.Red; // Or whatever
RTF.SelectionFont = new Font("Arial", 12, FontStyle.Bold); // you like
nextHigh = RTF.Text.IndexOf(txSearch, nextHigh + txSearch.Length, StringComparison.OrdinalIgnoreCase);
}

try this code :
void ParseLine(string line)
{
Regex r = new Regex("([ \\t{}():;])");
String[] tokens = r.Split(line);
foreach (string token in tokens)
{
// Set the tokens default color and font.
richTextBox1.SelectionColor = Color.Black;
richTextBox1.SelectionFont = new Font("Courier New", 10, FontStyle.Regular);
// Check whether the token is a keyword.
String[] keywords = { "Author", "Date", "Title", "Description", };
for (int i = 0; i < keywords.Length; i++)
{
if (keywords[i] == token)
{
// Apply alternative color and font to highlight keyword.
richTextBox1.SelectionColor = Color.Blue;
richTextBox1.SelectionFont = new Font("Courier New", 10, FontStyle.Bold);
break;
}
}
richTextBox1.SelectedText = token;
}
richTextBox1.SelectedText = "\n";
}
and after fill your string str with your method call my method :
string strRich =
"Author : Habib\nDate : 2012-08-10 \nTitle : mytitle \nDescription : desc\n";
Regex r = new Regex("\\n");
String[] lines = r.Split(strRich);
foreach (string l in lines)
{
ParseLine(l);
}
enjoy.