Develop Reference

Splitting large text field c#

EDIT: i have problem which i cant solve. I have large text file. I want select from this file only special data for me.
My code:
class Program
{
static string ticket = "";
static string openTime = "";
static string type = "";
static float size;
static string item = "";
static float price;
static string closeTime = "";
static float priceC;
static float commission;
static float swap;
static float trade;
static void Main(string[] args)
{
ReadFile.ReadAllFile("..\\..\\..\\File.txt");
}
}
public static class ReadFile
{
public static string ReadAllFile(string file)
{
string content = "";
using (StreamReader sr = new StreamReader(file))
{
content = sr.ReadToEnd();
}
Console.WriteLine(content);
return content;
}
}
One line from text file:
18388699 2021.09.03 14:40:14 buy 0.01 eurusd 1.18720 1.16211 1.17961 1.17201 0.00 -0.69 -12.96
In this text there are spaces. I want split this values to my strings.
This code reads the whole text from this text file. But i need select only data to my string from this file. Is there some method or funkcion which can select only important text passages?
Sorry for previous post, i dont want whole script. I am sreaching for some tips and tricks how to do that :D English is not my native language, then i cant describe my problem perfectly, but i tried my best :D

I would probably do something like this:
static void Main()
{
foreach (var line in File.ReadLines(#"..\..\..\File.txt"))
{
var fields = line.Split();
var ticket = fields[0];
var openTime = DateTime.Parse(fields[1] + " " + fields[2], CultureInfo.InvariantCulture);
var price = decimal.Parse(fields[6], CultureInfo.InvariantCulture);
Console.WriteLine($"{ticket}, {openTime}, {price}");
}
}
Read each line of the file using File.ReadLines().
Split on spaces using String.Split().
Index into the fields to get at the data you want.
ticket is just the first field.
For openTime you need to join the second and third field. I also chose to parse to a DateTime.
For things like prices and quantities I would use a decimal data type. In your code you have a float, I would not use that. float's have very low precision, you might get round off error with those. double's are better, but might still have the same problem. The recommended data type for calculations like these is decimal.

Read string word by word with .Substring?

I'v got the following String string gen = "Action;Adventure;Drama;Horror;
I tried to seperate the string word by word with .substring like: gen.Substring(gen.IndexOf(';')+1, gen.IndexOf(';'))
But my output is just "Advent".
Any help?
Background: The string collects the names of checkboxes that are checked. The string is then saved in a database.
I want to read out the string an check each checkbox on another form.

Just split it:
var parts = gen.Split(';');
(Then you can iterate over that via foreach.)

Split it like this:
public class Example
{
public static void Main()
{
String value = "Action;Adventure;Drama;Horror";
Char delimiter = ';';
String[] substrings = value.Split(delimiter);
foreach (var substring in substrings)
Console.WriteLine(substring);
}
}

Splitting a string which contain multiple symbols to get specific values

I cannot believe I am having trouble with this following string
String filter = "name=Default;pattern=%%;start=Last;end=Now";
This is a short and possibly duplicate question, but how would I split this string to get:
string Name = "Default";
string Pattern = "%%" ;
string start = "Last" ;
string end = "Now" ;
Reason why I ask is my deadline is very soon, and this is literally the last thing I must do. I'm Panicking, and I'm stuck on this basic command. I tried:
pattern = filter.Split(new string[] { "pattern=", ";" },
StringSplitOptions.RemoveEmptyEntries)[1]; //Gets the pattern
startDate = filter.Split(new string[] { "start=", ";" },
StringSplitOptions.RemoveEmptyEntries)[1]; //Gets the start date
I happen to get the pattern which I needed, but as soon as I try to split start, I get the value as "Pattern=%%"
What can I do?
Forgot to mention
The list in this string which needs splitting may not be in any particular order . this is a single sample of a string which will be read out of a stringCollection (reading these filters from Properties.Settings.Filters

Using string.Split this is a two stage process.
In the first case split on ; to get an array of keyword and value pairs:
string[] values = filter.Split(';');
Then loop over the resultant list splitting on = to get the keywords and values:
foreach (string value in values)
{
string[] pair = value.Split('=');
string key = pair[0];
string val = pair[1];
}

String filter = "name=Default;pattern=%%;start=Last;end=Now";
string[] temp = filter.Split('=');
string name = temp[1].Split(';')[0];
string pattern = temp[2].Split(';')[0];
string start = temp[3].Split(';')[0];
string end = temp[4].Split(';')[0];

This should do the trick:
string filter = "name=Default;pattern=%%;start=Last;end=Now";
// Make a dictionary.
var lookup = filter
.Split(';')
.Select(keyValuePair => keyValuePair.Split('='))
.ToDictionary(parts => parts[0], parts => parts[1]);
// Get values out of the dictionary.
string name = lookup["name"];
string pattern = lookup["pattern"];
string start = lookup["start"];
string end = lookup["end"];

The start date ends up at the thrird position in the array:
startDate = filter.Split(new string[] { "start=", ";" }, StringSplitOptions.RemoveEmptyEntries)[2];
Instead of splitting the string once for each value, you might want to split it into the separate key-value pairs, then split each pair:
string[] pairs = filter.Split(';');
string[] values = pairs.Select(pair => pair.Split('=')[1]).ToArray();
string name = values[0];
string pattern = values[1];
string start = values[2];
string end = values[3];
(This code of course assumes that the key-value pairs always come in the same order.)
You could also split the string into intersperced array, so that every other item is a key or a value:
string[] values = filter.Split(new string[] { "=", ";" }, StringSplitOptions.None);
string name = values[1];
string pattern = values[3];
string start = values[5];
string end = values[7];
Edit:
To handle key-values in any order, make a lookup from the string, and pick values from it:
ILookup<string, string> values =
filter.Split(';')
.Select(s => s.Split('='))
.ToLookup(p => p[0], p => p[1]);
string name = values["name"].Single();
string pattern = values["pattern"].Single();
string start = values["start"].Single();
string end = values["end"].Single();
You can use SingleOrDefault if you want to support values being missing from the string:
string name = values["name"].SingleOrDefault() ?? "DefaultName";
The lookup also supports duplicate key-value pairs. If there might be duplicates, just loop through the values:
foreach (var string name in values["name"]) {
// do something with the name
}

Well I tried something like this:
var result = "name=Default;pattern=%%;start=Last;end=Now".Split(new char[]{'=',';'});
for(int i=0;i<result.Length; i++)
{
if(i%2 == 0) continue;
Console.WriteLine(result[i]);
}
and the output is:
Default
%%
Last
Now
Is this what you want?

You see, the thing is now that your Split on filter a second time still starts from the beginning of the string, and it matches against ;, so since the string hasn't changed, you still retrieve previous matches (so your index accessor is off by X).
You could break this down into it's problem parts, such that:
var keyValues = filter.Split(';');
var name = keyValues[0].Split('=')[1];
var pattern = keyValues[1].Split('=')[1];
var start = keyValues[2].Split('=')[1];
var end = keyValues[3].Split('=')[1];
Note that the above code is potentially prone to error, and as such should be properly altered.

You can use the following:
String filter = "name=Default;pattern=%%;start=Last;end=Now";
string[] parts = filter.Split(';');
string Name = parts[0].Substring(parts[0].IndexOf('=') + 1);
string Pattern = parts[1].Substring(parts[1].IndexOf('=') + 1);
string start = parts[2].Substring(parts[2].IndexOf('=') + 1);
string end = parts[3].Substring(parts[3].IndexOf('=') + 1);

Use this:
String filter = "name=Default;pattern=%%;start=Last;end=Now";
var parts = filter.Split(';').Select(x => x.Split('='))
.Where(x => x.Length == 2)
.Select(x => new {key = x[0], value=x[1]});
string name = "";
string pattern = "";
string start = "";
string end = "";
foreach(var part in parts)
{
switch(part.key)
{
case "name":
name = part.value;
break;
case "pattern":
pattern = part.value;
break;
case "start":
start = part.value;
break;
case "end":
end = part.value;
break;
}
}
If you don't need the values in named variables, you only need the second line. It returns an enumerable with key/value pairs.
My solution has the added benefits that the order of those key/value pairs in the string is irrelevant and it silently ignores invalid parts instead of crashing.

I found a simple solution on my own too. Most of your answers would have worked if the list would have been in the same order every single time, but it wont be. the format however, will always stay the same. The solution is a simple iteration using a foreach loop, and then checking if it starts with a certain word, namely, the word I am looking for, like Name, Pattern etc.
Probably not the most cpu efficient way of doing it, but it is C# for dummies level. Really brain-fade level.
Here is my beauty.
foreach (string subfilter in filter.Split(';')) //filter.Split is a string [] which can be iterated through
{
if (subfilter.ToUpper().StartsWith("PATTERN"))
{
pattern = subfilter.Split('=')[1];
}
if (subfilter.ToUpper().StartsWith("START"))
{
startDate = subfilter.Split('=')[1];
}
if (subfilter.ToUpper().StartsWith("END"))
{
endDate = subfilter.Split('=')[1];
}
}

C# Template parsing and matching with text file

Need some ideas how to solve this problem.
I have a template file what describes the line in the text file. For example:
Template
[%f1%]|[%f2%]|[%f3%]"[%f4%]"[%f5%]"[%f6%]
Text file
1234|1234567|123"12345"12"123456
Now i need to read in the fields from the text file. In the template file fields are described with [%some name%]. Allso in the template file there is set what the field separators are, in this example here there are | and ". The lenght of the fields can change through different files but the separators will stay the same. What would be the best way to read in the template and by template read in the text file?
EDIT: Text file has multiple rows, like this:
1234|1234567|123"12345"12"123456"\r\n
1234|field|123"12345"12"asdasd"\r\n
123sd|1234567|123"asdsadf"12"123456"\r\n
45gg|somedata|123"12345"12"somefield"\r\n
EDIT2: Ok, lets make it even harder. Some fields can contain binary data and i know the starting and end position of the binary data field. I should be able to mark those fields in the template and then the parser will know that this field is binary. How to solve this problem?

I would create a regex based on the template and then parse the text file using that:
class Parser
{
private static readonly Regex TemplateRegex =
new Regex(#"\[%(?<field>[^]]+)%\](?<delim>[^[]+)?");
readonly List<string> m_fields = new List<string>();
private readonly Regex m_textRegex;
public Parser(string template)
{
var textRegexString = '^' + TemplateRegex.Replace(template, Evaluator) + '$';
m_textRegex = new Regex(textRegexString);
}
string Evaluator(Match match)
{
// add field name to collection and create regex for the field
var fieldName = match.Groups["field"].Value;
m_fields.Add(fieldName);
string result = "(.*?)";
// add delimiter to the regex, if it exists
// TODO: check, that only last field doesn't have delimiter
var delimGroup = match.Groups["delim"];
if (delimGroup.Success)
{
string delim = delimGroup.Value;
result += Regex.Escape(delim);
}
return result;
}
public IDictionary<string, string> Parse(string text)
{
var match = m_textRegex.Match(text);
var groups = match.Groups;
var result = new Dictionary<string, string>(m_fields.Count);
for (int i = 0; i < m_fields.Count; i++)
result.Add(m_fields[i], groups[i + 1].Value);
return result;
}
}

You can parse the template using regular expressions. An expression like this will match each field definition and separator:
Match m = Regex.Match(template, #"^(\[%(?<name>.+?)%\](?<separator>.)?)+$")
The match will contain two named groups for (name and separator), each of which will contain a number of captures for each time they matched in the input string. In your example, the separator group would have one less capture than the name group.
You can then iterate over the captures, and use the results to extract the fields from the input string and store the values, like this:
if( m.Success )
{
Group name = m.Groups["name"];
Group separator = m.Groups["separator"];
int index = 0;
Dictionary<string, string> fields = new Dictionary<string, string>();
for( int x = 0; x < name.Captures.Count; ++x )
{
int separatorIndex = input.Length;
if( x < separator.Captures.Count )
separatorIndex = input.IndexOf(separator.Captures[x].Value, index);
fields.Add(name.Captures[x].Value, input.Substring(index, separatorIndex - index));
index = separatorIndex + 1;
}
// Do something with results.
}
Obviously in a real program you'd have to account for invalid input and such, which I didn't do here.

I would do this with a few lines of code. Loop through your template row, grabbing all text between "[" as the variable name and everything else as a terminator. Read all the text to the terminal, assign it to the variable name, repeat.

1- Use API for that sscanf(line, format, __arglist) check here
2- Use string split Like:
public IEnumerable<int> GetDataFromLines(string[] lines)
{
//handle the output data
List<int> data = new List<int>();
foreach (string line in lines)
{
string[] seperators = new string[] { "|", "\"" };
string[] results = line.Split(seperators, StringSplitOptions.RemoveEmptyEntries);
foreach (string result in results)
{
data.Add(int.Parse(result));
}
}
return data;
}
Test it with line:
line = "1234|1234567|123\"12345\"12\"123456";
string[] lines = new string[] { line };
GetDataFromLines(lines);
//output list items are:
1234
1234567
123
12345
12
123456

Searching strings in txt file

I have a .txt file with a list of 174 different strings. Each string has an unique identifier.
For example:
123|this data is variable|
456|this data is variable|
789|so is this|
etc..
I wish to write a programe in C# that will read the .txt file and display only one of the 174 strings if I specify the ID of the string I want. This is because in the file I have all the data is variable so only the ID can be used to pull the string. So instead of ending up with the example about I get just one line.
eg just
123|this data is variable|
I seem to be able to write a programe that will pull just the ID from the .txt file and not the entire string or a program that mearly reads the whole file and displays it. But am yet to wirte on that does exactly what I need. HELP!
Well the actual string i get out from the txt file has no '|' they were just in the example. An example of the real string would be: 0111111(0010101) where the data in the brackets is variable. The brackets dont exsist in the real string either.
namespace String_reader
{
class Program
{
static void Main(string[] args)
{
String filepath = #"C:\my file name here";
string line;
if(File.Exists(filepath))
{
StreamReader file = null;
try
{
file = new StreamReader(filepath);
while ((line = file.ReadLine()) !=null)
{
string regMatch = "ID number here"; //this is where it all falls apart.
Regex.IsMatch (line, regMatch);
Console.WriteLine (line);// When program is run it just displays the whole .txt file
}
}
}
finally{
if (file !=null)
file.Close();
}
}
Console.ReadLine();
}
}
}

Use a Regex. Something along the lines of Regex.Match("|"+inputString+"|",#"\|[ ]*\d+\|(.+?)\|").Groups[1].Value
Oh, I almost forgot; you'll need to substitute the d+ for the actual index you want. Right now, that'll just get you the first one.
The "|" before and after the input string makes sure both the index and the value are enclosed in a | for all elements, including the first and last. There's ways of doing a Regex without it, but IMHO they just make your regex more complicated, and less readable.

Assuming you have path and id.
Console.WriteLine(File.ReadAllLines(path).Where(l => l.StartsWith(id + "|")).FirstOrDefault());

Use ReadLines to get a string array of lines then string split on the |

You could use Regex.Split method

FileInfo info = new FileInfo("filename.txt");
String[] lines = info.OpenText().ReadToEnd().Split(' ');
foreach(String line in lines)
{
int id = Convert.ToInt32(line.Split('|')[0]);
string text = Convert.ToInt32(line.Split('|')[1]);
}

Read the data into a string
Split the string on "|"
Read the items 2 by 2: key:value,key:value,...
Add them to a dictionary
Now you can easily find your string with dictionary[key].

first load the hole file to a string.
then try this:
string s = "123|this data is variable| 456|this data is also variable| 789|so is this|";
int index = s.IndexOf("123", 0);
string temp = s.Substring(index,s.Length-index);
string[] splitStr = temp.Split('|');
Console.WriteLine(splitStr[1]);
hope this is what you are looking for.

private static IEnumerable<string> ReadLines(string fspec)
{
using (var reader = new StreamReader(new FileStream(fspec, FileMode.Open, FileAccess.Read, FileShare.Read)))
{
while (!reader.EndOfStream)
yield return reader.ReadLine();
}
}
var dict = ReadLines("input.txt")
.Select(s =>
{
var split = s.Split("|".ToArray(), 2);
return new {Id = Int32.Parse(split[0]), Text = split[1]};
})
.ToDictionary(kv => kv.Id, kv => kv.Text);
Please note that with .NET 4.0 you don't need the ReadLines function, because there is ReadLines
You can now work with that as any dictionary:
Console.WriteLine(dict[12]);
Console.WriteLine(dict[999]);
No error handling here, please add your own

You can use Split method to divide the entire text into parts sepparated by '|'. Then all even elements will correspond to numbers odd elements - to strings.
StreamReader sr = new StreamReader(filename);
string text = sr.ReadToEnd();
string[] data = text.Split('|');
Then convert certain data elements to numbers and strings, i.e. int[] IDs and string[] Strs. Find the index of the given ID with idx = Array.FindIndex(IDs, ID.Equals) and the corresponding string will be Strs[idx]
List <int> IDs;
List <string> Strs;
for (int i = 0; i < data.Length - 1; i += 2)
{
IDs.Add(int.Parse(data[i]));
Strs.Add(data[i + 1]);
}
idx = Array.FindIndex(IDs, ID.Equals); // we get ID from input
answer = Strs[idx];