We Keep Coding

create lines with strings for each blank line until it reaches line 100

I'm new to C# i need help on reading a file that currently has 7 lines of text but I need it to write "Line PlaceHolder" after those 7 lines until it reaches line 100 in the text file. This is what i have so far and i know it's my failed attempt: EDIT: It's good but only issue is an exception is throw that a process is already using the text file, how do I solve this to read/write that file at the same time??
public void ReadFile()
{
if (File.Exists(AccountsFile))
{
using (StreamReader Reader = new StreamReader(AccountsFile))
using (StreamWriter Writer = new StreamWriter((AccountsFile)))
{
for (int i = 0; i < 100; i++)
{
string line;
if ((line = Reader.ReadLine()) == null)
{
Writer.WriteLine("Line Placeholder");
}
}
}
}
else
{
File.Create(AccountsFile);
}
}

You could first read the file contents into an array using File.ReadAllLines, get the array .Length (representing the number of lines in the file), and subtract that number from 100 to see how many lines you need to write. If the number is greater than zero, then create a List<string> with that many empty lines and write those lines to the end of the file using File.AppendAllLines:
// See how many lines we need to add
var newLinesNeeded = 100 - File.ReadAllLines(AccountsFile).Length;
// Add them if needed
if (newLinesNeeded > 0)
{
// Create a list of empty lines
var blankLines = new List<string>();
for(int i = 0; i < newLinesNeeded; i++)
{
blankLines.Add("");
}
// Append them to our file
File.AppendAllLines(AccountsFile, blankLines);
}

Looks like you are just missing an else:
public void ReadFile()
{
if (File.Exists(AccountsFile))
{
using (StreamReader Reader = new StreamReader(AccountsFile))
using (StreamWriter Writer = new StreamWriter((AccountsFile)))
{
for (int i = 0; i < 100; i++)
{
string line;
if ((line = Reader.ReadLine()) == null)
{
Writer.WriteLine("Line Placeholder");
}
else
Writer.WriteLine(line);
}
}
}
else
{
File.Create(AccountsFile);
}
}

this may work if you do not mind opening the file as Read/Write
using (FileStream fileStream = File.Open(AccountsFile, FileMode.OpenOrCreate, FileAccess.ReadWrite))
{
var streamWriter = new StreamWriter(fileStream);
var streamReader = new StreamReader(fileStream);
var i = 0;
// read and count the lines
while (streamReader.ReadLine() != null){
i++;
}
// if any more lines are needed write them
while (i++ < 100)
{
streamWriter.WriteLine("Line Placeholder");
}
streamWriter.Flush();
}

Compare two csv files in C#

I want to compare two csv files and print the differences in a file. I currently use the code below to remove a row. Can I change this code so that it compares two csv files or is there a better way in c# to compare csv files?
List<string> lines = new List<string>();
using (StreamReader reader = new StreamReader(System.IO.File.OpenRead(path)))
{
string line;
while ((line = reader.ReadLine()) != null)
{
if (line.Contains(csvseperator))
{
string[] split = line.Split(Convert.ToChar(scheidingsteken));
if (split[selectedRow] == value)
{
}
else
{
line = string.Join(csvseperator, split);
lines.Add(line);
}
}
}
}
using (StreamWriter writer = new StreamWriter(path, false))
{
foreach (string line in lines)
writer.WriteLine(line);
}
}

Here is another way to find differences between CSV files, using Cinchoo ETL - an open source library
For the below sample CSV files
sample1.csv
id,name
1,Tom
2,Mark
3,Angie
sample2.csv
id,name
1,Tom
2,Mark
4,Lu
METHOD 1:
Using Cinchoo ETL, below code shows how to find differences between rows by all columns
var input1 = new ChoCSVReader("sample1.csv").WithFirstLineHeader().ToArray();
var input2 = new ChoCSVReader("sample2.csv").WithFirstLineHeader().ToArray();
using (var output = new ChoCSVWriter("sampleDiff.csv").WithFirstLineHeader())
{
output.Write(input1.OfType<ChoDynamicObject>().Except(input2.OfType<ChoDynamicObject>(), ChoDynamicObjectEqualityComparer.Default));
output.Write(input2.OfType<ChoDynamicObject>().Except(input1.OfType<ChoDynamicObject>(), ChoDynamicObjectEqualityComparer.Default));
}
sampleDiff.csv
id,name
3,Angie
4,Lu
Sample fiddle: https://dotnetfiddle.net/nwLeJ2
METHOD 2:
If you want to do the differences by id column,
var input1 = new ChoCSVReader("sample1.csv").WithFirstLineHeader().ToArray();
var input2 = new ChoCSVReader("sample2.csv").WithFirstLineHeader().ToArray();
using (var output = new ChoCSVWriter("sampleDiff.csv").WithFirstLineHeader())
{
output.Write(input1.OfType<ChoDynamicObject>().Except(input2.OfType<ChoDynamicObject>(), new ChoDynamicObjectEqualityComparer(new string[] { "id" })));
output.Write(input2.OfType<ChoDynamicObject>().Except(input1.OfType<ChoDynamicObject>(), new ChoDynamicObjectEqualityComparer(new string[] { "id" })));
}
Sample fiddle: https://dotnetfiddle.net/t6mmJW

If you only want to compare one column you can use this code:
List<string> lines = new List<string>();
List<string> lines2 = new List<string>();
try
{
StreamReader reader = new StreamReader(System.IO.File.OpenRead(pad));
StreamReader read = new StreamReader(System.IO.File.OpenRead(pad2));
string line;
string line2;
//With this you can change the cells you want to compair
int comp1 = 1;
int comp2 = 1;
while ((line = reader.ReadLine()) != null && (line2 = read.ReadLine()) != null)
{
string[] split = line.Split(Convert.ToChar(seperator));
string[] split2 = line2.Split(Convert.ToChar(seperator));
if (line.Contains(seperator) && line2.Contains(seperator))
{
if (split[comp1] != split2[comp2])
{
//It is not the same
}
else
{
//It is the same
}
}
}
reader.Dispose();
read.Dispose();
}
catch
{
}

How do I show my data via a loop outside of a StreamReader

So I am trying display my data from a StreamReader outside of the using portion. I am able to display it all INSIDE of the StreamReader however showing it OUTSIDE of the StreamReader is proving more complicated.
I understand that my while loop inside the StreamReader will show all the data I need (and it is). But I need it to show from the for loop that I have at the bottom. (While loop was left in just as a reference).
When I run it through the for loop I either get
"end
end
end
end"
or
"end
of
record
indicator"
I get the "Ends" when i use the array index number in the for loop, and the "end of record indicator" when i use the "i".
How can I get it to display what my while loop is displaying?
class Program
{
static void Main(string[] args)
{
string[] lineOutVar;
using (StreamReader readerOne = new StreamReader("../../FileIOExtraFiles/DataFieldsLayout.txt"))
{
string lineReader = readerOne.ReadLine();
string[] lineOutput = lineReader.Split('\n');
lineOutVar = lineOutput;
while (readerOne.EndOfStream == false)
{
lineOutVar = readerOne.ReadLine().Split();
Console.WriteLine(lineOutVar[0]);
}
}
for (int i = 0; i < lineOutVar.Length; i++)
{
Console.WriteLine(lineOutVar[0]);
}

Use List class.
List<string> lineOutVar = new List<string>();
using (System.IO.StreamReader readerOne = new System.IO.StreamReader("../../FileIOExtraFiles/DataFieldsLayout.txt"))
{
while(readerOne.EndOfStream == false)
{
string lineReader = readerOne.ReadLine();
lineOutVar.Add(lineReader); //add the line to the list of string
}
}
foreach(string line in lineOutVar) //loop through each of the line in the list of string
{
Console.WriteLine(line);
}

to get the content:
string[] lineOutVar;
List<string[]> lst_lineOutVar = new List<string[]>();
using (StreamReader readerOne = new StreamReader("E:\\TEST\\sample.txt"))
{
string lineReader = readerOne.ReadLine();
string[] lineOutput = lineReader.Split('\n');
lineOutVar = lineOutput;
while (readerOne.EndOfStream == false)
{
lineOutVar = new string[1];
lineOutVar = readerOne.ReadLine().Split();
lst_lineOutVar.Add(lineOutVar);
//Console.WriteLine(lineOutVar[0]);
}
String getcontent = string.Empty;
foreach (var getLst in lst_lineOutVar)
{
getcontent = getcontent + "," + getLst[0].ToString();
}
Console.WriteLine(getcontent);
}

You could also just skip the StreamReader and use File.ReadAllLines:
string[] lineOutVar = File.ReadAllLines("../../FileIOExtraFiles/DataFieldsLayout.txt");
Now you have an array of the file lines, and you can loop over them and split them however you like.

Convert .XYZ to .csv using c#

Hi i am using this method to replace " " to "," but is failing when i try to use it on data that have 32 millions lines. Is anyone knows how to modify it to make it running?
List<String> lines = new List<String>();
//loop through each line of file and replace " " sight to ","
using (StreamReader sr = new StreamReader(inputfile))
{
int id = 1;
int i = File.ReadAllLines(inputfile).Count();
while (sr.Peek() >= 0)
{
//Out of memory issuee
string fileLine = sr.ReadLine();
//do something with line
string ttt = fileLine.Replace(" ", ", ");
//Debug.WriteLine(ttt);
lines.Add(ttt);
//lines.Add(id++, 'ID');
}
using (StreamWriter writer = new StreamWriter(outputfile, false))
{
foreach (String line in lines)
{
writer.WriteLine(line+","+id);
id++;
}
}
}
//change extension to .csv
FileInfo f = new FileInfo(outputfile);
f.MoveTo(Path.ChangeExtension(outputfile, ".csv"));
I general i am trying to convert big .XYZ file to .csv format and add incremental field at the end. I am using c# for first time in my life to be honest :) Can you help me?

See my comment above - you could modify your reading / writing as follows :
using (StreamReader sr = new StreamReader(inputfile))
{
using (StreamWriter writer = new StreamWriter(outputfile, false))
{
int id = 1;
while (sr.Peek() >= 0)
{
string fileLine = sr.ReadLine();
//do something with line
string ttt = fileLine.Replace(" ", ", ");
writer.WriteLine(ttt + "," + id);
id++;
}
}
}

Delete specific line from a text file?

I need to delete an exact line from a text file but I cannot for the life of me workout how to go about doing this.
Any suggestions or examples would be greatly appreciated?
Related Questions
Efficient way to delete a line from a text file (C#)

If the line you want to delete is based on the content of the line:
string line = null;
string line_to_delete = "the line i want to delete";
using (StreamReader reader = new StreamReader("C:\\input")) {
using (StreamWriter writer = new StreamWriter("C:\\output")) {
while ((line = reader.ReadLine()) != null) {
if (String.Compare(line, line_to_delete) == 0)
continue;
writer.WriteLine(line);
}
}
}
Or if it is based on line number:
string line = null;
int line_number = 0;
int line_to_delete = 12;
using (StreamReader reader = new StreamReader("C:\\input")) {
using (StreamWriter writer = new StreamWriter("C:\\output")) {
while ((line = reader.ReadLine()) != null) {
line_number++;
if (line_number == line_to_delete)
continue;
writer.WriteLine(line);
}
}
}

The best way to do this is to open the file in text mode, read each line with ReadLine(), and then write it to a new file with WriteLine(), skipping the one line you want to delete.
There is no generic delete-a-line-from-file function, as far as I know.

One way to do it if the file is not very big is to load all the lines into an array:
string[] lines = File.ReadAllLines("filename.txt");
string[] newLines = RemoveUnnecessaryLine(lines);
File.WriteAllLines("filename.txt", newLines);

Hope this simple and short code will help.
List linesList = File.ReadAllLines("myFile.txt").ToList();
linesList.RemoveAt(0);
File.WriteAllLines("myFile.txt"), linesList.ToArray());
OR use this
public void DeleteLinesFromFile(string strLineToDelete)
{
string strFilePath = "Provide the path of the text file";
string strSearchText = strLineToDelete;
string strOldText;
string n = "";
StreamReader sr = File.OpenText(strFilePath);
while ((strOldText = sr.ReadLine()) != null)
{
if (!strOldText.Contains(strSearchText))
{
n += strOldText + Environment.NewLine;
}
}
sr.Close();
File.WriteAllText(strFilePath, n);
}

You can actually use C# generics for this to make it real easy:
var file = new List<string>(System.IO.File.ReadAllLines("C:\\path"));
file.RemoveAt(12);
File.WriteAllLines("C:\\path", file.ToArray());

This can be done in three steps:
// 1. Read the content of the file
string[] readText = File.ReadAllLines(path);
// 2. Empty the file
File.WriteAllText(path, String.Empty);
// 3. Fill up again, but without the deleted line
using (StreamWriter writer = new StreamWriter(path))
{
foreach (string s in readText)
{
if (!s.Equals(lineToBeRemoved))
{
writer.WriteLine(s);
}
}
}

Read and remember each line
Identify the one you want to get rid
of
Forget that one
Write the rest back over the top of
the file

I cared about the file's original end line characters ("\n" or "\r\n") and wanted to maintain them in the output file (not overwrite them with what ever the current environment's char(s) are like the other answers appear to do). So I wrote my own method to read a line without removing the end line chars then used it in my DeleteLines method (I wanted the option to delete multiple lines, hence the use of a collection of line numbers to delete).
DeleteLines was implemented as a FileInfo extension and ReadLineKeepNewLineChars a StreamReader extension (but obviously you don't have to keep it that way).
public static class FileInfoExtensions
{
public static FileInfo DeleteLines(this FileInfo source, ICollection<int> lineNumbers, string targetFilePath)
{
var lineCount = 1;
using (var streamReader = new StreamReader(source.FullName))
{
using (var streamWriter = new StreamWriter(targetFilePath))
{
string line;
while ((line = streamReader.ReadLineKeepNewLineChars()) != null)
{
if (!lineNumbers.Contains(lineCount))
{
streamWriter.Write(line);
}
lineCount++;
}
}
}
return new FileInfo(targetFilePath);
}
}
public static class StreamReaderExtensions
{
private const char EndOfFile = '\uffff';
/// <summary>
/// Reads a line, similar to ReadLine method, but keeps any
/// new line characters (e.g. "\r\n" or "\n").
/// </summary>
public static string ReadLineKeepNewLineChars(this StreamReader source)
{
if (source == null)
throw new ArgumentNullException(nameof(source));
char ch = (char)source.Read();
if (ch == EndOfFile)
return null;
var sb = new StringBuilder();
while (ch != EndOfFile)
{
sb.Append(ch);
if (ch == '\n')
break;
ch = (char)source.Read();
}
return sb.ToString();
}
}

Are you on a Unix operating system?
You can do this with the "sed" stream editor. Read the man page for "sed"

What?
Use file open, seek position then stream erase line using null.
Gotch it? Simple,stream,no array that eat memory,fast.
This work on vb.. Example search line culture=id where culture are namevalue and id are value and we want to change it to culture=en
Fileopen(1, "text.ini")
dim line as string
dim currentpos as long
while true
line = lineinput(1)
dim namevalue() as string = split(line, "=")
if namevalue(0) = "line name value that i want to edit" then
currentpos = seek(1)
fileclose()
dim fs as filestream("test.ini", filemode.open)
dim sw as streamwriter(fs)
fs.seek(currentpos, seekorigin.begin)
sw.write(null)
sw.write(namevalue + "=" + newvalue)
sw.close()
fs.close()
exit while
end if
msgbox("org ternate jua bisa, no line found")
end while
that's all..use #d