Develop Reference

Read specific values out of a text-file and put them in a list

I have a text-file with many lines, each line looks like this:
"string string double double" between each value is a space. I'd like to read out the first string and last double of every line and put these two values in a existing list. That is my code so far, but it doesnt really work.
private void bOpen_Click(object sender, RoutedEventArgs e)
{
bool exists = File.Exists(#"C:\Users\p2\Desktop\Liste.txt");
if (exists == true)
{
StringBuilder sb = new StringBuilder();
using (StreamReader sr = new StreamReader(#"C:\Users\p2\Desktop\Liste.txt"))
{
Vgl comp = new Vgl();
comp.name = Abzahlungsdarlehenrechner.zgName;
comp.gErg = Abzahlungsdarlehenrechner.zgErg;
GlobaleDaten.VglDaten.Add(comp);
int i = 0;
string line = File.ReadLines(#"Liste.txt").Skip(0).Take(1).First();
while ((line = sr.ReadLine()) != null)
{
sb.Append((line));
listBox.Items.Add(line);
GlobaleDaten.VglDaten.Add(comp);
i++;
}
}
}
I have already read this, but it didnt help How do I read specific value[...]

You can try Linq:
var source = File
.ReadLines(#"C:\Users\p2\Desktop\Liste.txt")
.Select(line => line.Split(' '))
.Select(items => new Vgl() {
name = items[0],
gErg = double.Parse(items[3])
});
// If you want to add into existing list
GlobaleDaten.VglDaten.AddRange(source);
// If you want to create a new list
//List<Vgl> list = source.ToList();

how about
List<Vgl> Result = File.ReadLines(#"C:\Users\p2\Desktop\Liste.txt")
.Select(x => new Vgl()
{
name = x.Split(' ').First(),
gErg = decimal.Parse(x.Split(' ').Last(), NumberStyles.AllowCurrencySymbol)
})
.ToList();
I would avoid storing money within doulbe values because this could lead to rounding issues. Use decimal instead. Examples here: Is a double really unsuitable for money?

You can use:
string[] splitBySpace = line.Split(' ');
string first = splitBySpace.ElementAt(0);
decimal last = Convert.ToDecimal(splitBySpace.ElementAt(splitBySpace.Length - 1));
Edit : To Handle Currency symbol:
string[] splitBySpace = line.Split(' ');
string pattern = #"[^0-9\.\,]+";
string first = splitBySpace.ElementAt(0);
string last = (new Regex(pattern)).Split(splitBySpace.ElementAt(splitBySpace.Length - 1))
.FirstOrDefault();
decimal lastDecimal;
bool success = decimal.TryParse(last, out lastDecimal);

I agree with #Dmitry and fubo, if you are looking for alternatives, you could try this.
var source = File
.ReadLines(#"C:\Users\p2\Desktop\Liste.txt")
.Select(line =>
{
var splits = line.Split(' '));
return new Vgl()
{
name = splits[0],
gErg = double.Parse(splits[3])
};
}

use string.split using space as the delimiter on line to the string into an array with each value. Then just access the first and last array element. Of course, if you aren't absolutely certain that each line contains exactly 4 values, you may want to inspect the length of the array to ensure there are at least 4 values.
reference on using split:
https://msdn.microsoft.com/en-us/library/ms228388.aspx

Read the whole file as a string.
Split the string in a foreach loop using \r\n as a row separator. Add each row to a list of strings.
Iterate through that list and split again each record in another loop using space as field separator and put them into another list of strings.
Now you have all the four fields containig one row. Now just use First and Last methods to get the first word and the last number.

Unable to Split the string accordingly

I know this question would have been asked infinite number of times, but I'm kinda stuck.
I have a string something like
"Doc1;Doc2;Doc3;12"
it can be something like
"Doc1;Doc2;Doc3;Doc4;Doc5;56"
Its like few pieces of strings separated by semicolon, followed by a number or id.
I need to extract the number/id and the strings separately.
To be exact, I can have 2 strings: one having "Doc1;Doc2;Doc3" or "Doc1;Doc2;Doc3;Doc4" and the other having just the number/id as "12" or "34" or "45" etc.
And yeah I am using C# 3.5
I understand its a pretty easy and witty question, but this guy is stuck.
Assistance required from experts.
Regards
Anurag

string.LastIndexOf and string.Substring are the keys to what you're trying to do.
var str = "Doc1;Doc2;Doc3;12";
var ind = str.LastIndexOf(';');
var str1 = str.Substring(0, ind);
var str2 = str.Substring(ind+1);

One way:
string[] tokens = str.Split(';');
var docs = tokens.Where(s => s.StartsWith("Doc", StringComparison.OrdinalIgnoreCase));
var numbers = tokens.Where(s => s.All(Char.IsDigit));

String docs = s.Substring(0, s.LastIndexOf(';'));
String number = s.Substring(s.LastIndexOf(';') + 1);

One possible approach would be this:
var ids = new List<string>();
var nums = new List<string>();
foreach (var s in input.Split(';'))
{
int val;
if (!int.TryParse(s, out val)) { ids.Add(s); }
else { nums.Add(s); }
}
where input is something like Doc1;Doc2;Doc3;Doc4;Doc5;56. Now, ids will house all of the Doc1 like values and nums will house all of the 56 like values.

you can use StringTokenizer functionality.
http://www.c-sharpcorner.com/UploadFile/pseabury/JavaLikeStringTokenizer11232005015829AM/JavaLikeStringTokenizer.aspx
split string using ";"
StringTokenizer st = new StringTokenizer(src1,";");
collect final String. that will be your ID.

You may try one of two options: (assuming your input string is in string str;
Approach 1
Get LastIndexOf(';')
Split the string based on the index. This will give you string and int part.
Split the string part and process it
Process the int part
Approach 2
Split the string on ;
Run a for loop - for (int i = 0; i < str.length - 2; i++) - this is the string part
Process str[length - 1] separately - this is the int part
Please take this as a starting point as there could be other approaches to implement a solution for this

string actual = "Doc1;Doc2;Doc3;12";
int lstindex = actual.LastIndexOf(';');
string strvalue = actual.Substring(0, lstindex);
string id = actual.Substring(lstindex + 1);

C# Best way to retrieve strings that's in quotation mark?

Suppose I am given a following text (in a string array)
engine.STEPCONTROL("00000000","02000001","02000043","02000002","02000007","02000003","02000008","02000004","02000009","02000005","02000010","02000006","02000011");
if("02000001" == 1){
dimlevel = 1;
}
if("02000001" == 2){
dimlevel = 3;
}
I'd like to extract the strings that's in between the quotation mark and put it in a separate string array. For instance, string[] extracted would contain 00000000, 02000001, 02000043....
What is the best approach for this? Should I use regular expression to somehow parse those lines and split it?

Personally I don't think a regular expression is necessary. If you can be sure that the input string is always as described and will not have any escape sequences in it or vary in any other way, you could use something like this:
public static string[] ExtractNumbers(string[] originalCodeLines)
{
List<string> extractedNumbers = new List<string>();
string[] codeLineElements = originalCodeLines[0].Split('"');
foreach (string element in codeLineElements)
{
int result = 0;
if (int.TryParse(element, out result))
{
extractedNumbers.Add(element);
}
}
return extractedNumbers.ToArray();
}
It's not necessarily the most efficient implementation but it's quite short and its easy to see what it does.

that could be
string data = "\"00000000\",\"02000001\",\"02000043\"".Replace("\"", string.Empty);
string[] myArray = data.Split(',');
or in 1 line
string[] data = "\"00000000\",\"02000001\",\"02000043\"".Replace("\"", string.Empty).Split(',');

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];