Develop Reference

Remove Non-ASCII characters from XML file C#

I am trying to write a program to remove open an XML file with Non-ASCII characters and replace those characters with spaces and save and close the file.
Thats basically it, just open the file remove all the non ascii characters and save/close the file.
Here is my code:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Xml;
using System.IO;
using System.Text.RegularExpressions;
namespace RemoveSpecial
{
class Program
{
static void Main(string[] args)
{
string pth_input = string.Empty;
string pth_output = string.Empty;
for (int i = 1; i < args.Length; i++)
{
//input one
string p_input = args[0];
pth_input = p_input;
pth_input = pth_input.Replace(#"\", #"\\");
//output
string p_output = args[2];
pth_output = p_output;
pth_output = pth_output.Replace(#"\", #"\\");
}
//s = Regex.Replace(s, #"[^\u0000-\u007F]+", string.Empty);
string lx;
using (StreamReader sr = new StreamReader(pth_input))
{
using (StreamWriter x = new StreamWriter(pth_output))
{
while ((lx = sr.ReadLine()) != null)
{
string text = sr.ReadToEnd();
Regex.Replace(text, #"[^\u0000-\u007F]+", "", RegexOptions.Compiled);
x.Write(text);
} sr.Close();
}
}
}
}
}
Thanks in advance guys.

According to documentation, the first string is an input parameter (and not passed by reference, so it could not change anyway). The result of the replacement is in the return value, like so:
var result = Regex.Replace(text, #"[^\u0000-\u007F]+", "", RegexOptions.Compiled);
x.Write(result);
Note that RegexOptions.Compiled might decrease performance here. It makes sense only if you reuse the same regular expression instance on multiple strings. You can still do that, if you create the RegEx instance outside of the loop:
var regex = new Regex(#"[^\u0000-\u007F]+", RegexOptions.Compiled);
using (var sr = new StreamReader(pth_input))
{
using (var x = new StreamWriter(pth_output))
{
while ((lx = sr.ReadLine()) != null)
{
var text = sr.ReadToEnd();
var result = regex.Replace(text, String.Empty);
x.Write(result);
}
}
}

Update string at a specific line so it doesn't update duplicates in string?

I know how to go to a specific line but I don't know how to update that specific line in the string. I have tried the Replace functionality but it overwrites the duplicates as well. Any ideas?
static string GetLine(string text, int lineNo)
{
string[] lines = text.Replace("\r", "").Split('\n');
return lines.Length >= lineNo ? lines[lineNo - 1] : null;
}
static void Main(string[] args)
{
string file = "D:\\random.text";
string contents = "";
string text="random";
contents = File.ReadAllText(file);
finale=GetLine(contents,lines);
// Console.ReadLine();
if(finale.Contains(text))
{
finale.Replace(text,"Random");
System.Console.WriteLine(finale);
Console.ReadLine();
}
}

Strings are immutable type which means you cant alter an existing string. string.Replace returns the replaced string and you need to assign it back.
if(finale.Contains(text))
{
finale = finale.Replace(text,"Random"); //<- note here
System.Console.WriteLine(finale);
Console.ReadLine();
}
From there you need to rebuild the string from the string array as noted by Philippe. A complete example (but untested):
static string[] GetLines(string text)
{
return text.Replace("\r", "").Split('\n');
}
static string GetLine(string[] lines, int lineNo)
{
return lines.Length >= lineNo ? lines[lineNo - 1] : null;
}
static void Main(string[] args)
{
string file = "D:\\random.text";
string contents = "";
string text="random";
contents = File.ReadAllText(file);
var lines = GetLines(contents);
finale = GetLine(lines, lineNo);
//Console.ReadLine();
if (finale == null)
return;
if(finale.Contains(text))
{
finale = finale.Replace(text, "Random");
System.Console.WriteLine(finale);
Console.ReadLine();
}
lines[lineNo] = finale;
contents = string.Join('\n', lines);
}
And best of all, you don't need all that split function at all. .NET has that functionality and it does lazily (on demand) which is a bonus.
See for File.ReadLines if you're using .NET 4.0 and above.

The quickest solution would be to keep the array returned by Split and then use String.Join to rebuild what you started with.

Just rebuild the string with string builder as you read the file.
static void Main(string[] args)
{
string file = "D:\\random.txt";
string find = "random";
string replace = "Random";
StringBuilder resultList = new StringBuilder();
using (var stream = File.OpenText(file))
{
while (stream.Peek() >= 0)
{
string line = stream.ReadLine();
if(line == find)
{
line = replace;
}
resultList.AppendLine(line);
}
}
string result = resultList.ToString();
Console.WriteLine(result);
Console.Read();
}

Counting number of words in a text file

I'm trying to count the number of words from a text file, namely this, to start.
This is a test of the word count program. This is only a test. If your
program works successfully, you should calculate that there are 30
words in this file.
I am using StreamReader to put everything from the file into a string, and then use the .Split method to get the number of individual words, but I keep getting the wrong value when I compile and run the program.
using System;
using System.IO;
class WordCounter
{
static void Main()
{
string inFileName = null;
Console.WriteLine("Enter the name of the file to process:");
inFileName = Console.ReadLine();
StreamReader sr = new StreamReader(inFileName);
int counter = 0;
string delim = " ,.";
string[] fields = null;
string line = null;
while(!sr.EndOfStream)
{
line = sr.ReadLine();
}
fields = line.Split(delim.ToCharArray());
for(int i = 0; i < fields.Length; i++)
{
counter++;
}
sr.Close();
Console.WriteLine("The word count is {0}", counter);
}
}

Try to use regular expression, e.g.:
int count = Regex.Matches(input, #"\b\w+\b").Count;

this should work for you:
using System;
using System.IO;
class WordCounter
{
static void Main()
{
string inFileName = null;
Console.WriteLine("Enter the name of the file to process:");
inFileName = Console.ReadLine();
StreamReader sr = new StreamReader(inFileName);
int counter = 0;
string delim = " ,."; //maybe some more delimiters like ?! and so on
string[] fields = null;
string line = null;
while(!sr.EndOfStream)
{
line = sr.ReadLine();//each time you read a line you should split it into the words
line.Trim();
fields = line.Split(delim.ToCharArray(), StringSplitOptions.RemoveEmptyEntries);
counter+=fields.Length; //and just add how many of them there is
}
sr.Close();
Console.WriteLine("The word count is {0}", counter);
}
}

A couple hints.
What if you just have the sentence "hi" what would be your output?
Your counter calculation is: from 0 through fields.Length, increment counter. How are fields.Length and your counter related?

you're probably getting a one off error, try something like this
counter = 0;
while(!sr.EndOfStream)
{
line = sr.ReadLine();
fields = line.Split(delim.ToCharArray());
counter += field.length();
}
there is no need to iterate over the array to count the elements when you can get the number directly

using System.IO;
using System;
namespace solution
{
class Program
{
static void Main(string[] args)
{
var readFile = File.ReadAllText(#"C:\test\my.txt");
var str = readFile.Split(new char[] { ' ', '\n'}, StringSplitOptions.RemoveEmptyEntries);
System.Console.WriteLine("Number of words: " + str.Length);
}
}
}

//Easy method using Linq to Count number of words in a text file
/// www.techhowdy.com
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace FP_WK13
{
static class Util
{
public static IEnumerable<string> GetLines(string yourtextfile)
{
TextReader reader = new StreamReader(yourtextfile);
string result = string.Empty;
string line;
while ((line = reader.ReadLine()) != null)
{
yield return line;
}
reader.Close();
}
// Word Count
public static int GetWordCount(string str)
{
int words = 0;
string s = string.Empty;
var lines = GetLines(str);
foreach (var item in lines)
{
s = item.ToString();
words = words + s.Split(' ').Length;
}
return words;
}
}
}

C# text creation issue

This is whats going on. I have a huge text file that is suppose to be 1 line per entry. The issue is sometimes the line is broken with a new line.
I edit this entire file and wherever the file doesn't begin with ("\"A) i need to append the current line to the previous line ( replacing \n with " "). Everything I come up with keeps appending the line to a new line. Any help is appricated...
CODE:
public void step1a()
{
string begins = ("\"A");
string betaFilePath = #"C:\ext.txt";
string[] lines = File.ReadAllLines(betaFilePath);
foreach (string line in lines)
{
if (line.StartsWith(begins))
{
File.AppendAllText(#"C:\xt2.txt",line);
File.AppendAllText(#"C:\xt2.txt", "\n");
}
else
{
string line2 = line.Replace(Environment.NewLine, " ");
File.AppendAllText(#"C:\xt2.txt",line2);
}
}
}
Example:
Orig:
"\"A"Hero|apple|orange|for the fun of this
"\"A"Hero|apple|mango|lots of fun always
"\"A"Her|apple|fruit|no
pain is the way
"\"A"Hero|love|stackoverflowpeople|more fun
Resulting:
"\"A"Hero|apple|orange|for the fun of this
"\"A"Hero|apple|mango|lots of fun always
"\"A"Her|apple|fruit|no pain is the way
"\"A"Hero|love|stackoverflowpeople|more fun
my problem isnt the finding the if (line.StartsWith(begins)) its the else statement, it appends line2 to a new line

it seems like your string is not well formated...
try this "\"\\\"A\"" instead
public void step1a()
{
string begins = ("\"\\\"A\"");
string betaFilePath = #"C:\ext.txt";
string[] lines = File.ReadAllLines(betaFilePath);
foreach (string line in lines)
{
if (line.StartsWith(begins))
{
File.AppendAllText(#"C:\xt2.txt",line);
File.AppendAllText(#"C:\xt2.txt", "\n");
}
else
{
string line2 = line.Replace(Environment.NewLine, " ");
File.AppendAllText(#"C:\xt2.txt",line2);
}
}
}

This does what you want:
CopyFileRemovingStrayNewlines(#"C:\ext.txt", #"C:\xt2.txt", #"""\""A");
With this method:
public static void CopyFileRemovingStrayNewlines(string sourcePath, string destinationPath, string linePrefix)
{
string[] lines = File.ReadAllLines(sourcePath);
bool firstLine = true;
foreach (string line in lines)
{
if (line.StartsWith(linePrefix))
{
if (!firstLine)
File.AppendAllText(destinationPath, Environment.NewLine);
else
firstLine = false;
File.AppendAllText(destinationPath, line);
}
else
{
File.AppendAllText(destinationPath, " ");
File.AppendAllText(destinationPath, line);
}
}
}
It does have the problem of appending to an existing file, though. I suggest using a StreamWriter rather than AppendAllText. Like this:
public static void CopyFileRemovingStrayNewlines(string sourcePath, string destinationPath, string linePrefix)
{
string[] lines = File.ReadAllLines(sourcePath);
bool firstLine = true;
using (StreamWriter writer = new StreamWriter(destinationPath, false))
{
foreach (string line in lines)
{
if (line.StartsWith(linePrefix))
{
if (!firstLine)
writer.WriteLine();
else
firstLine = false;
writer.Write(line);
}
else
{
writer.Write(" ");
writer.Write(line);
}
}
}
}

Your problem is that the \ is a C# escape code.
Your string is parsed as "A, because \" is the escape code for a single ".
You should make the begins string an #-string, which does not use escape codes.
You will then need to escape the " by doubling it up.
For example:
const string begins = #"\""A";
Note that the best way to do this is to use a StreamWriter, like this:
using(StreamWriter writer = File.Create(#"C:\xt2.txt"))
{
foreach (string line in lines)
{
if (line.StartsWith(begins))
writer.WriteLine(); //Close the previous line
writer.Write(line);
}
}

Based on #SLaks's example here is some code that should do the trick:
public static void step1a()
{
string betaFilePath = #"C:\ext.txt";
string[] lines = File.ReadAllLines(betaFilePath);
using (StreamWriter writer = new StreamWriter(File.Create(#"C:\xt2.txt")))
{
string buffer = null;
foreach (string line in lines)
{
if (!line.StartsWith(begins))
{
writer.WriteLine(buffer + line);
buffer = null;
}
else
{
if (buffer != null)
writer.WriteLine(buffer);
buffer = line;
}
}
if(buffer != null)
Console.Out.WriteLine(buffer);
}
}

C#: How do I prepend text to each line in a string?

What would an implementation of 'MagicFunction' look like to make the following (nunit) test pass?
public MagicFunction_Should_Prepend_Given_String_To_Each_Line()
{
var str = #"line1
line2
line3";
var result = MagicFunction(str, "-- ");
var expected = #"-- line1
-- line2
-- line3";
Assert.AreEqual(expected, result);
}

string MagicFunction(string str, string prepend)
{
str = str.Replace("\n", "\n" + prepend);
str = prepend + str;
return str;
}
EDIT:
As others have pointed out, the newline characters vary between environments. If you're only planning to use this function on files that were created in the same environment then System.Environment will work fine. However, if you create a file on a Linux box and then transfer it over to a Windows box you'll want to specify a different type of newline. Since Linux uses \n and Windows uses \r\n this piece of code will work for both Windows and Linux files. If you're throwing Macs into the mix (\r) you'll have to come up with something a little more involved.

Use .Select on a list of the lines.
private static string MagicFunction(string str, string prefix)
{
string[] lines = str.Split(new[] { '\n' });
return string.Join("\n", lines.Select(s => prefix + s).ToArray());
}

How about:
string MagicFunction(string InputText) {
public static Regex regex = new Regex(
"(^|\\r\\n)",
RegexOptions.IgnoreCase
| RegexOptions.CultureInvariant
| RegexOptions.IgnorePatternWhitespace
| RegexOptions.Compiled
);
// This is the replacement string
public static string regexReplace =
"$1-- ";
// Replace the matched text in the InputText using the replacement pattern
string result = regex.Replace(InputText,regexReplace);
return result;
}

var result = "-- " + str.Replace(Environment.NewLine, Environment.NewLine + "-- ");
if you want it cope with either Windows (\r\n) NewLines or Unix ones (\n) then:
var result = "-- " + str.Replace("\n", "\n-- ");
No need to touch the \r as it is to be left where it was before. If however you want to cross between Unix and Windows then:
var result = "-- " + str.Replace("\r","").Replace("\n", Enviornment.NewLine + "-- ");
Will do it and return the result in the local OS's format

You could do it like that :
public string MagicFunction2(string str, string prefix)
{
bool first = true;
using(StringWriter writer = new StringWriter())
using(StringReader reader = new StringReader(str))
{
string line;
while((line = reader.ReadLine()) != null)
{
if (!first)
writer.WriteLine();
writer.Write(prefix + line);
first = false;
}
return writer.ToString();
}
}

You could split the string by Environment.NewLine, and then add the prefix to each of those string, and then join them by Environment.NewLine.
string MagicFunction(string prefix, string orignalString)
{
List<string> prefixed = new List<string>();
foreach (string s in orignalString.Split(new[]{Environment.NewLine}, StringSplitOptions.None))
{
prefixed.Add(prefix + s);
}
return String.Join(Environment.NewLine, prefixed.ToArray());
}

How about this. It uses StringBuilder in case you are planning on prepending a lot of lines.
string MagicFunction(string input)
{
StringBuilder sb = new StringBuilder();
StringReader sr = new StringReader(input);
string line = null;
using(StringReader sr = new StringReader(input))
{
while((line = sr.ReadLine()) != null)
{
sb.Append(String.Concat("-- ", line, System.Environment.NewLine));
}
}
return sb.ToString();
}

Thanks all for your answers. I implemented the MagicFunction as an extension method. It leverages Thomas Levesque's answer but is enhanced to handle all major environments AND assumes you want the output string to use the same newline terminator of the input string.
I favored Thomas Levesque's answer (over Spencer Ruport's, Fredrik Mork's, Lazarus, and JDunkerley) because it was the best performing. I'll post performance results on my blog and link here later for those interested.
(Obviously, the function name of 'MagicFunctionIO' should be changed. I went with 'PrependEachLineWith')
public static string MagicFunctionIO(this string self, string prefix)
{
string terminator = self.GetLineTerminator();
using (StringWriter writer = new StringWriter())
{
using (StringReader reader = new StringReader(self))
{
bool first = true;
string line;
while ((line = reader.ReadLine()) != null)
{
if (!first)
writer.Write(terminator);
writer.Write(prefix + line);
first = false;
}
return writer.ToString();
}
}
}
public static string GetLineTerminator(this string self)
{
if (self.Contains("\r\n")) // windows
return "\r\n";
else if (self.Contains("\n")) // unix
return "\n";
else if (self.Contains("\r")) // mac
return "\r";
else // default, unknown env or no line terminators
return Environment.NewLine;
}