Develop Reference

Reading from txt file to array/list<>

I need to read all of .txt file and save data to array/list. File looks like this:
row11 row12 row13
row21 row22 row23
row31 row32 row33
between strings are only spaces.
Next I will insert data from array/list<> to mysql, but it is not problem.
Thanks.
EDIT: I need insert 3 columns to mysql like .txt file.

Use String.Split(Char[], StringSplitOptions) where the first parameter specifies that you want to split your string using spaces and tabs, and the second parameter specifies that you ignore empty entries (for cases where there are multiple spaces between entries)
Use this code:
var lines = System.IO.File.ReadAllLines(#"D:\test.txt");
var data = new List<List<string>>();
foreach (var line in lines)
{
var split = line.Split(new[]{' ', '\t'}, StringSplitOptions.RemoveEmptyEntries);
data.Add(split.ToList());
}

You can use File.ReadLines() to read the lines from the file, and then Regex.Split() to split each line into multiple strings:
static IEnumerable<String> SplitLines(string path, string splitPattern)
{
foreach (string line in File.ReadAllLines(path))
foreach (string part in Regex.Split(line, splitPattern))
yield return part;
}
To split by white space, you can use the regex pattern \s+:
var individualStrings = SplitLines(#"C:\path\to\file.txt", #"\s+");
You can use the ToList() extension method to convert it to a list:
List<string> individualStrings = SplitLines(#"D:\test\rows.txt", #"\s+").ToList();

As long as there are never spaces in the "values", then a simple line-by line parser will work.
A simple example
var reader = new StreamReader(filePath);
var resultList = new List<List<string>>();
string line;
while ((line = reader.ReadLine()) != null)
{
var currentValues = new List<string>();
// You can also use a StringBuilder
string currentValue = String.Empty;
foreach (char c in line)
{
if (Char.IsWhiteSpace(c))
{
if (currentValue.Length > 0)
{
currentValues.Add(currentValue);
currentValue = String.Empty;
}
continue;
}
currentValue += c;
}
resultList.Add(currentValues);
}

Here's a nifty one-liner based off Amadeusz's answer:
var lines = File.ReadAllLines(fileName).Select(l => l.Split(new[] { ' ', '\t' }, StringSplitOptions.RemoveEmptyEntries)).SelectMany(words => words);

Read file, check correctness of column, write file C#

I need to check certain columns of data to make sure there are no trailing blank spaces. At first thought I thought it would be very easy, but after attempting to achieve the goal I have got stuck.
I know that there should be 6-digits in the column I need to check. If there is less I will reject, if there are more I will trim the blank spaces. After doing that for the entire file, I want to write it back to the file with the same delimiters.
This is my attempt:
Everything seems to be working correctly except for writing the file.
if (File.Exists(filename))
{
using (StreamReader sr = new StreamReader(filename))
{
string lines = sr.ReadLine();
string[] delimit = lines.Split('|');
while (delimit[count] != "COLUMN_DATA_TO_CHANGE")
{
count++;
}
string[] allLines = File.ReadAllLines(#filename);
foreach(string nextLine in allLines.Skip(1)){
string[] tempLine = nextLine.Split('|');
if (tempLine[count].Length == 6)
{
checkColumn(tempLine);
writeFile(tempLine);
}
else if (tempLine[count].Length > 6)
{
tempLine[count] = tempLine[count].Trim();
checkColumn(tempLine);
}
else
{
throw new Exception("Not enough numbers");
}
}
}
}
}
public static void checkColumn(string[] str)
{
for (int i = 0; i < str[count].Length; i++)
{
char[] c = str[count].ToCharArray();
if (!Char.IsDigit(c[i]))
{
throw new Exception("A non-digit is contained in data");
}
}
}
public static void writeFile(string[] str)
{
string temp;
using (StreamWriter sw = new StreamWriter(filename+ "_tmp", false))
{
StringBuilder builder = new StringBuilder();
bool firstColumn = true;
foreach (string value in str)
{
if (!firstColumn)
{
builder.Append('|');
}
if (value.IndexOfAny(new char[] { '"', ',' }) != -1)
{
builder.AppendFormat("\"{0}\"", value.Replace("\"", "\"\""));
}
else
{
builder.Append(value);
}
firstColumn = false;
}
temp = builder.ToString();
sw.WriteLine(temp);
}
}
If there is a better way to go about this, I would love to hear it. Thank you for looking at the question.
edit:
file structure-
country| firstname| lastname| uniqueID (column I am checking)| address| etc
USA|John|Doe|123456 |5 main street|
notice the blank space after the 6

var oldLines = File.ReadAllLines(filePath):
var newLines = oldLines.Select(FixLine).ToArray();
File.WriteAllLines(filePath, newLines);
string FixLine(string oldLine)
{
string fixedLine = ....
return fixedLine;
}

The main problem with writing the file is that you're opening the output file for each output line, and you're opening it with append=false, which causes the file to be overwritten every time. A better approach would be to open the output file one time (probably right after validating the input file header).
Another problem is that you're opening the input file a second time with .ReadAllLines(). It would be better to read the existing file one line at a time in a loop.
Consider this modification:
using (StreamWriter sw = new StreamWriter(filename+ "_tmp", false))
{
string nextLine;
while ((nextLine = sr.ReadLine()) != null)
{
string[] tempLine = nextLine.Split('|');
...
writeFile(sw, tempLine);

Reading individual words into an array using streamreader C#

I am trying to get a list of words (below) to be put into an array. I want each word to be in it's own index.
Here is my code that I have so far.
string badWordsFilePath = openFileDialog2.FileName.ToString();
StreamReader sr = new StreamReader(badWordsFilePath);
string line = sr.ReadToEnd();
string[] badWordsLine = line.Split(' ');
int BadWordArrayCount = 0;
foreach (string word in badWordsLine)
{
badWords[BadWordArrayCount] = word;
BadWordArrayCount = BadWordArrayCount + 1;
}
int test = badWords.Length;
MessageBox.Show("Words have been imported!");
BadWordsImported = true;
Here is the list of words I want to import.
label
invoice
post
document
postal
calculations
copy
fedex
statement
financial
dhl
usps
8
notification
n
irs
ups
no
delivery
ticket
If someone could give me an example of how to get this to work, that would be a huge help.

Simplified code:
string badWordsFilePath = openFileDialog2.FileName.ToString();
string[] badWords = File.ReadAllLines(badWordsFilePath);
int test = badWords.Length;
MessageBox.Show("Words have been imported!");
BadWordsImported = true;

If every word starts on a new line then you do not need to create a for loop. The Split method will convert to an array for you.
string badWordsFilePath = openFileDialog2.FileName.ToString();
StreamReader sr = new StreamReader(badWordsFilePath);
string line = sr.ReadToEnd();
string[] badWords = line.Split('\n');

You are splitting on space, but there is a newline between each word. Split on newline instead:
string[] badWordsLine = line.Split(new string[]{ Environment.NewLine }, StringSplitOptions.RemoveEmptyEntries);
Then you have to create the array to put the words in:
badWords = new string[badWordsLine.Length];
However, to loop through a string array just to copy the strings to a string array seems pointless. Just assing the string array to the variable. Also, you forgot to close the stream reader, which is best taken care of with a using block:
string badWordsFilePath = openFileDialog2.FileName.ToString();
string line;
using (StreamReader sr = new StreamReader(badWordsFilePath)) {}
line = sr.ReadToEnd();
}
badWords = line.Split(new string[]{ Environment.NewLine }, StringSplitOptions.RemoveEmptyEntries);
int test = badWords.Length;
MessageBox.Show("Words have been imported!");
BadWordsImported = true;

Maybe try this modification? It allows on splitting on various white spaces.
string badWordsFilePath = openFileDialog2.FileName.ToString();
StreamReader sr = new StreamReader(badWordsFilePath);
string line = sr.ReadToEnd();
string[] badWordsLine = line.Split(new string[] {" ", "\t", "\r\n"}, StringSplitOptions.RemoveEmptyEntries);
int BadWordArrayCount = 0;
foreach (string word in badWordsLine)
{
badWords[BadWordArrayCount] = word;
BadWordArrayCount = BadWordArrayCount + 1;
}
int test = badWords.Length;
MessageBox.Show("Words have been imported!");
BadWordsImported = true;

Do you have to use a StreamReader? If you do not have to, then this code is clearer (in my opinion).
string text = File.ReadAllText(badWordsFilePath);
string[] words = Regex.Split(text, #"\s+");
If you're 100% certain that each word is on its own line and there are no empty lines, this might be overkill; and the File.ReadAllLines suggestion by #Ulugbek Umirov is simpler.

Extract data from text file

I need to extract some data from a text file and insert to columns in excel sheet. I know how to do this if the rows and the length of the string is known.
try
{
using (System.IO.StreamReader sr = new System.IO.StreamReader("test.txt")
{
string line;
while ((line = sr.ReadLine()) != null)
{
listSNR.Items.Add(line.Substring (78,4));
}
}
}
But the particular text file is complex and the starting index or the length cannot be provided. But the starting word (PCPU01) of the row is known.
Eg: PCPU01,T2716,0.00,0.01,0.00,0.00
output:
T2716 0 0.01 0 0
In that case can somebody please let me know how to extract the texts?

using(System.IO.StreamReader sr = new System.IO.StreamReader("test.txt"))
{
string line;
while((line = sr.ReadLine()) != null)
{
string[] split = line.Split(',');
//...
}
}
split[0] will return "PCPU01", split[1] "T2716" and so on.

You can split one string into an array of strings, separated by a given character. This way, you could split the source string by a comma and use the resulting strings to build your output. Example:
string source = "PCPU01,T2716,0.00,0.01,0.00,0.00";
string[] parts = source.Split(',');
StringBuilder result = new StringBuilder();
result.Append(parts[1]); // The second element in the array, i.e. T2716
result.Append(" ");
result.Append(parts[2]); // 0.00
... // And so on...
return result.ToString() // return a string, not a StringBuilder

I hope this helps a little bit. You might have to tweak it to your needs. But this is a higher level code that gives you general idea of extracting data off a notepad.
DialogResult result = openFileDialog.ShowDialog();
Collection<Info> _infoCollection = new Collection<Info>();
Collection<string> listOfSubDomains = new Collection<string>();
string[] row;
string line;
// READ THE FILE AND STORE IT IN INFO OBJECT AND STORE TAHT INFO OBJECT IN COLLECTION
try
{
using (StreamReader reader = new StreamReader(openFileDialog.FileName))
{
while((line = reader.ReadLine()) != null)
{
Info _info = new Info();
row = line.Split(' ');
_info.FirstName = row[0];
_info.LastName = row[1];
_info.Email = row[2];
_info.Id = Convert.ToInt32(row[3]);
_infoCollection.Add(_info);
}
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}

thanks for the answers. What i wanted is to identify the particular line in the text file and split the line into columns. So i was able to do this by calling a GetLine method:
string line15=GetLine(#"test.txt",15);
public string GetLine(string fileName, int line)
{
using (System.IO.StreamReader ssr = new System.IO.StreamReader("test.txt"))
//using (var ssr = new StreamReader("test.txt"))
{
for (int i = 1; i < line; i++)
ssr.ReadLine();
return ssr.ReadLine();
}
}
Then i splitted this line by using the delimiter (,)

This was my approach in C#. It takes a string input (which you can get out of a text file) and an int with which line you want to get. It then separates the string at a given seperator char to a list which in turn is then read out. If the given line number is lower than the count of the created list, the entry is given back.
public string GetLine(string multiline,int line)
{
List<string> lines = new List<string>();
lines = multiline.Split('\n').ToList<string>();
return lines.Count >= line ? lines[line] : "";
}

How to read values from a comma separated file?

I want to read words in a text file of a line separated by commas in c sharp.
For example, I want to read this line:
9/10/2011 10:05,995.4,998.8,995.4,997.5,118000
and get the values: 9/10/2011 10:05, 995.4, 998.8, 995.4, 997.5 and 118000.
Next, I also need to change the format of the date to MMddYYYY, and of the time to HHmmss (e.g. 100500).
I am using this code for reading is there anything wrong
private void button1_Click(object sender, EventArgs e)
{
StreamReader reader1 = File.OpenText(Path1);
string str = reader1.ReadToEnd();
reader1.Close();
reader1.Dispose();
// File.Delete(Path1);
string[] Strarray = str.Split(new char[] { Strings.ChrW(7) });
int abc = Strarray.Length - 1;
int xyz = 0;
bool status = true;
while (xyz <= abc)
{
try
{
status = true;
string[] strarray1 = Strarray[xyz].Split(",".ToCharArray());
string SecName = strarray1[0];
int a2 = 0;
while (status) //If the selected list is empty or the text file has selected name this will execute
{
status = false;
string SecSym = strarray1[1];
int DT = int.Parse(strarray1[2]);
int TM = int.Parse(strarray1[3]);
float O = float.Parse(strarray1[2]);
float H = float.Parse(strarray1[3]);
float L = float.Parse(strarray1[4]);
float C = float.Parse(strarray1[5]);
double OI = double.Parse(Convert.ToString(0));
float V = float.Parse(strarray1[6]);
// string a = string.Concat(SecName, ",",SecSym,",", DT, ",", TM, ",", O, ",", H, ",", L);
//writer.WriteLine(a);
}
}
catch
{ }
}
}
}

.Net comes with a ready CSV parser you can use to get your data. It's a part of VB.net, but you can easily use it in C# by adding a reference to the assembly Microsoft.VisualBasic (it's OK, honesly), and a using statement: using Microsoft.VisualBasic.FileIO;.
The code should be simple to understand:
List<String[]> fileContent = new List<string[]>();
using(FileStream reader = File.OpenRead(#"data.csv")) // mind the encoding - UTF8
using(TextFieldParser parser = new TextFieldParser(reader))
{
parser.TrimWhiteSpace = true; // if you want
parser.Delimiters = new[] { "," };
parser.HasFieldsEnclosedInQuotes = true;
while (!parser.EndOfData)
{
string[] line = parser.ReadFields();
fileContent.Add(line);
}
}
CSV is fairly simple, but it may contain quoted values with commas and newlines, so using Split isn't the best option.

Use the String.Split method to get an array of strings:
string[] ar = line.Split(',')

This should get you started.
using System;
using System.IO;
public class Sample
{
public static void Main() {
using (StreamReader reader = new StreamReader("yourfile.txt")) {
string line = null;
while (null != (line = reader.ReadLine())) {
string[] values = line.Split(',');
DateTime date = DateTime.Parse(values[0];
float[] numbers = new float[values.Length - 1];
for (int i = 1; i < values.Length - 1; i++)
numbers[i - 1] = float.Parse(values[i]);
// do stuff with date and numbers
}
}
}
}
I have also posted a simple CsvReader class which may be helpful for you.

For a quick and simple solution, you can stream through the file and parse each line using String.Split like this:
using (var sr = File.OpenText("myfile.csv"))
{
string line;
while ((line = sr.ReadLine()) != null)
{
var fields = line.Split(',');
var date = DateTime.Parse(fields[0].Trim());
var value1 = fields[0].Trim();
}
}
However, this appraoch if fairly error prone, for a more robust solution check out the CsvReader project, it's excellent for parsing CSV files like this. It will handle field values with commas, trimming spaces before and after fields, and much more.
If you need to parse a date string from a format not recognised by DateTime.Parse, try using DateTime.ParseExact instead.

For 1st part of your task use Split method with , as separator. To convert string datetime from one format to another you need to convert that string to datetime(DateTime.Parse, DateTime.ParseExact) and then convert to final format using DateTime.ToString method.

rows contain your output
StreamReader sStreamReader = new StreamReader("File Path");
string AllData = sStreamReader.ReadToEnd();
string[] rows = AllData.Split(",".ToCharArray());