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Using a for loop to iterate from an array to a list

I have a text file that is divided up into many sections, each about 10 or so lines long. I'm reading in the file using File.ReadAllLines into an array, one line per element of the array, and I'm then I'm trying to parse each section of the file to bring back just some of the data. I'm storing the results in a list, and hoping to export the list to csv ultimately.
My for loop is giving me trouble, as it loops through the right amount of times, but only pulls the data from the first section of the text file each time rather than pulling the data from the first section and then moving on and pulling the data from the next section. I'm sure I'm doing something wrong either in my for loop or for each loop. Any clues to help me solve this would be much appreciated! Thanks
David
My code so far:
namespace ParseAndExport
{
class Program
{
static readonly string sourcefile = #"Path";
static void Main(string[] args)
{
string[] readInLines = File.ReadAllLines(sourcefile);
int counter = 0;
int holderCPStart = counter + 3;//Changed Paths will be an different number of lines each time, but will always start 3 lines after the startDiv
/*Need to find the start of the section and the end of the section and parse the bit in between.
* Also need to identify the blank line that occurs in each section as it is essentially a divider too.*/
int startDiv = Array.FindIndex(readInLines, counter, hyphens72);
int blankLine = Array.FindIndex(readInLines, startDiv, emptyElement);
int endDiv = Array.FindIndex(readInLines, counter + 1, hyphens72);
List<string> results = new List<string>();
//Test to see if FindIndexes work. Results should be 0, 7, 9 for 1st section of sourcefile
/*Console.WriteLine(startDiv);
Console.WriteLine(blankLine);
Console.WriteLine(endDiv);*/
//Check how long the file is so that for testing we know how long the while loop should run for
//Console.WriteLine(readInLines.Length);
//sourcefile has 5255 lines (elements) in the array
for (int i = 0; i <= readInLines.Length; i++)
{
if (i == startDiv)
{
results = (readInLines[i + 1].Split('|').Select(p => p.Trim()).ToList());
string holderCP = string.Join(Environment.NewLine, readInLines, holderCPStart, (blankLine - holderCPStart - 1)).Trim();
results.Add(holderCP);
string comment = string.Join(" ", readInLines, blankLine + 1, (endDiv - (blankLine + 1)));//in case the comment is more than one line long
results.Add(comment);
i = i + 1;
}
else
{
i = i + 1;
}
foreach (string result in results)
{
Console.WriteLine(result);
}
//csvcontent.AppendLine("Revision Number, Author, Date, Time, Count of Lines, Changed Paths, Comments");
/* foreach (string result in results)
{
for (int x = 0; x <= results.Count(); x++)
{
StringBuilder csvcontent = new StringBuilder();
csvcontent.AppendLine(results[x] + "," + results[x + 1] + "," + results[x + 2] + "," + results[x + 3] + "," + results[x + 4] + "," + results[x + 5]);
x = x + 6;
string csvpath = #"addressforcsvfile";
File.AppendAllText(csvpath, csvcontent.ToString());
}
}*/
}
Console.ReadKey();
}
private static bool hyphens72(String h)
{
if (h == "------------------------------------------------------------------------")
{
return true;
}
else
{
return false;
}
}
private static bool emptyElement(String ee)
{
if (ee == "")
{
return true;
}
else
{
return false;
}
}
}
}

It looks like you are trying to grab all of the lines in a file that are not "------" and put them into a list of strings.
You can try this:
var lineswithoutdashes = readInLines.Where(x => x != hyphens72).Select(x => x).ToList();
Now you can take this list and do the split with a '|' to extract the fields you wanted

The logic seems wrong. There are issues with the code in itself also. I am unsure what precisely you're trying to do. Anyway, a few hints that I hope will help:
The if (i == startDiv) checks to see if I equals startDiv. I assume the logic that happens when this condition is met, is what you refer to as "pulls the data from the first section". That's correct, given you only run this code when I equals startDiv.
You increase the counter I inside the for loop, which in itself also increases the counter i.
If the issue in 2. wouldn't exists then I'd suggest to not do the same operation "i = i + 1" in both the true and false conditions of the if (i == startDiv).
Given I assume this file might actually be massive, it's probably a good idea to not store it in memory, but just read the file line by line and process line by line. There's currently no obvious reason why you'd want to consume this amount of memory, unless it's because of the convenience of this API "File.ReadAllLines(sourcefile)". I wouldn't be too scared to read the file like this:
Try (BufferedReader br = new BufferedReader(new FileReader (file))) {
String line;
while ((line = br.readLine()) != null) {
// process the line.
}
}
You can skip the lines until you've passed where the line equals hyphens72.
Then for each line, you process the line with the code you provided in the true case of (i == startDiv), or at least, from what you described, this is what I assume you are trying to do.

int startDiv will return the line number that contains hyphens72.
So your current for loop will only copy to results for the single line that matches the calculated line number.
I guess you want to search the postion of startDiv in the current line?
const string hyphens72;
// loop over lines
for (var lineNumber = 0; lineNumber <= readInLines.Length; lineNumber++) {
string currentLine = readInLines[lineNumber];
int startDiv = currentLine.IndexOf(hyphens72);
// loop over characters in line
for (var charIndex = 0; charIndex < currentLine.Length; charIndex++) {
if (charIndex == startDiv) {
var currentCharacter = currentLine[charIndex];
// write to result ...
}
else {
continue; // skip this character
}
}
}

There are a several things which could be improved.
I would use ReadLines over File.ReadAllLines( because ReadAllLines reads all the lines at ones. ReadLines will stream it.
With the line results = (readInLines[i + 1].Split('|').Select(p => p.Trim()).ToList()); you're overwriting the previous results list. You'd better use results.AddRange() to add new results.
for (int i = 0; i <= readInLines.Length; i++) means when the length = 10 it will do 11 iterations. (1 too many) (remove the =)
Array.FindIndex(readInLines, counter, hyphens72); will do a scan. On large files it will take ages to completely read them and search in it. Try to touch a single line only ones.
I cannot test what you are doing, but here's a hint:
IEnumerable<string> readInLines = File.ReadLines(sourcefile);
bool started = false;
List<string> results = new List<string>();
foreach(var line in readInLines)
{
// skip empty lines
if(emptyElement(line))
continue;
// when dashes are found, flip a boolean to activate the reading mode.
if(hyphens72(line))
{
// flip state.. (start/end)
started != started;
}
if(started)
{
// I don't know what you are doing here precisely, do what you gotta do. ;-)
results.AddRange((line.Split('|').Select(p => p.Trim()).ToList()));
string holderCP = string.Join(Environment.NewLine, readInLines, holderCPStart, (blankLine - holderCPStart - 1)).Trim();
results.Add(holderCP);
string comment = string.Join(" ", readInLines, blankLine + 1, (endDiv - (blankLine + 1)));//in case the comment is more than one line long
results.Add(comment);
}
}
foreach (string result in results)
{
Console.WriteLine(result);
}

You might want to start with a class like this. I don't know whether each section begins with a row of hyphens, or if it's just in between. This should handle either scenario.
What this is going to do is take your giant list of strings (the lines in the file) and break it into chunks - each chunk is a set of lines (10 or so lines, according to your OP.)
The reason is that it's unnecessarily complicated to try to read the file, looking for the hyphens, and process the contents of the file at the same time. Instead, one class takes the input and breaks it into chunks. That's all it does.
Another class might read the file and pass its contents to this class to break them up. Then the output is the individual chunks of text.
Another class can then process those individual sections of 10 or so lines without having to worry about hyphens or what separates on chunk from another.
Now that each of these classes is doing its own thing, it's easier to write unit tests for each of them separately. You can test that your "processing" class receives an array of 10 or so lines and does whatever it's supposed to do with them.
public class TextSectionsParser
{
private readonly string _delimiter;
public TextSectionsParser(string delimiter)
{
_delimiter = delimiter;
}
public IEnumerable<IEnumerable<string>> ParseSections(IEnumerable<string> lines)
{
var result = new List<List<string>>();
var currentList = new List<string>();
foreach (var line in lines)
{
if (line == _delimiter)
{
if(currentList.Any())
result.Add(currentList);
currentList = new List<string>();
}
else
{
currentList.Add(line);
}
}
if (currentList.Any() && !result.Contains(currentList))
{
result.Add(currentList);
}
return result;
}
}

Replacing Matching File Names in String List

I have a main List of Files Filelist.The Main List Contains Full File Paths and there is a second list copylist it is poupulated by fetching the contents from a directory.I need to replace the File Names in Filelist that matches with the ones in the temporary folder,so i used the following code.
Filelist = new List<string>();
//Code to Populate File List from openfiledialog
try
{
copylist = Directory.GetFiles(temppath + #"\mydir\");
List<string> tempfiles = new List<string>(Filelist);
int x = 0;
foreach (string file in tempfiles)
{
for (int i = 0; i < copylist .Length; i++)
{
if (Path.GetFileName(file) == Path.GetFileName(copylist [i]))
{
MessageBox.Show("Removed: " + file + " \ninserted:" + copylist [i]);
Filelist.RemoveAt(x);
Filelist.Insert(x,copylist [i]);
}
x++;
}
}
}
catch (Exception)
{
}
I tested with 4 files... The File names matched when i checked manually(ie: the same file name in temp folder and in the FileList).The equality check ie:Path.GetFileName(file) == Path.GetFileName(copylist [i]) is satisfied for just 2 files and finally only 1 file is replaced in Filelist even though all 4 files are present in temp folder.
What im i doing wrong.Please advice.

The logic of your program relies on the fact that positions in tempfiles and Filelist are related, and that x corresponds to the position of file in tempfiles. In order for this to work you need to add a break inside the if, and move x++ to the outside loop:
foreach (string file in tempfiles) {
for (int i = 0; i < copylist .Length; i++) {
if (Path.GetFileName(file) == Path.GetFileName(copylist [i])) {
MessageBox.Show($"Removed: {file}\ninserted:{copylist [i])}";
Filelist.RemoveAt(x);
Filelist.Insert(x,copylist[i]);
break; // << Added
}
}
x++; // << Moved
}

Get number of lines in file and add first 40 characters

As part of an assignment -
The User selects a file extension (.txt, .bat, or .xyz)
A list of files from a folder with that extension is shown
The user then selects a file from the list and are shown the first 40 characters of each of its first four lines (or as many lines as present if less than four lines are recorded in the file). If there are more lines left in the file, output a string: “xx more lines are not shown.” (substitute xx with the correct number).
I can't seem to wrap my head around number 3. Any help or pointers are greatly appreciated.
namespace unit9Assignment
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
//add the extensions to the c box.
comboBox1.Items.Add(".txt");
comboBox1.Items.Add(".xyz");
comboBox1.Items.Add(".bat");
//make .txt the default selection
comboBox1.SelectedItem = ".txt";
tabControl1.SelectedIndexChanged += tabControl1_SelectedIndexChanged;
}
/******Tab Click Event********/
private void tabControl1_SelectedIndexChanged(Object sender, EventArgs e)
{
switch ((sender as TabControl).SelectedIndex)
{
case 0:
break;
case 1:
fileName(comboBox1.Text);
break;
case 2:
fileContent(Files.SelectedItem.ToString());
break;
}
}
/******Get Files Based on Selection*******/
public void fileName(string fileExt)
{
List<string> listOfFiles = new List<string>();
string[] fileExtArray = Directory.GetFiles(#"C:\Users\Public", "*" + fileExt);
foreach (string fileExtFile in fileExtArray)
{
listOfFiles.Add(fileExtFile);
}
Files.DataSource = listOfFiles;
}
/******Display 4 Lines # 40 Characters Per Line*********/
public void fileContent(string fileName)
{
int numberOfLines = File.ReadLines(#fileName).Count(),
remainingLines = numberOfLines - 4;
//THIS PRINTS OUT 4 LINES # 40 CHARACTERS PER LINE IF A FILE HAS LESS THAN 5 LINES
if (numberOfLines < 5)
{
foreach (string line in File.ReadLines(fileName))
{
richTextBox1.AppendText(line.Substring(0, 40) + Environment.NewLine);
Console.WriteLine(line.Substring(0, 40));
}
}
// NO CLUE WHAT TO DO
else
{
}
}
}
}

Rather than checking the number of lines in the file, why don't you just go ahead and start printing, and stop after 4 lines? Something like this:
StreamReader fileIn = new StreamReader(fileName);
for(int i=0; i<4 && !fileIn.EndOfStream; ++i)
{
string line = fileIn.ReadLine();
if(line.Length > 40)
richTextBox1.AppendText(line.Substring(0,40) + Environment.NewLine);
else
richTextBox1.AppendText(line + Environment.NewLine);
}
int j;
for(j=0; !fileIn.EndOfStream; ++j)
fileIn.ReadLine();
if(j>0)
richTextBox1.AppendText(j.ToString() + " more lines are not shown.";
fileIn.Close();
... To clarify, this would be your entire fileContent method. You actually do not need to know the number of lines in the file. Of course, this method won't work if you have more lines in your file than an int variable can hold, but I assume you're not working with such long files.

How about this:
public void fileContent(string fileName)
{
var lines = File.ReadLines(#fileName);
foreach (string line in lines.Take(4))
{
richTextBox1.AppendText(line.Substring(0, 40) + Environment.NewLine);
}
var remaining = lines.Count() - 4;
if (remaining > 0)
richTextBox1.AppendText(remaining + " more line(s) are not shown.");
}
The Take() documentation is here.

Giving answers to homework is bad practice. Instead here are some pointers to help you wrap your head around your problem:
//read a file
var lines = File.ReadLines("myfile");
//get the first 4 lines of your file
var first4 = lines.Take(4);
//get the first 40 characters of the first line of your file
var first40Chars = lines.FirstOrDefault().Take(40);
//get the remaining number of lines
var remainingCount = lines.Count() - 4;
Pulling up a dialog to show files is quite easy also. The WinForms FileDialog can help you there.

Auto Incrementing file names?

I have a list of files like so
abc.txt
pas.txt
tempr.txt
What I would like to do is to append english alphabets to theese file names ..
the result should look like this
abc_a.txt
pas_b.txt
tempr_c.txt
This process should continue till the last character (i.e 'z'). if there are more files then the file names would become
abc_a.txt
pas_b.txt
tempr_c.txt
.................
filename_z.txt
anotherfilename_a001.txt
Notice that the counter was again reset to the first character except an integer was attached to it.
This is the code that i have right now. Please note that it is NOT working ..
string alphabets= "abcdefghijklmnopqrstuvwxyz";
List<string> filenames = new List<string>();
filenames.Add("test1.txt");
filenames.Add("newfile.cs");
filenames.Add("test2.txt");
filenames.Add("newfile2.cs");
string currentFileNmae = string.Empty;
foreach(string s in filenames) {
char usedAlphabet = new char();
for(int i = 0;i<=alphabets.Length-1;i+=11) {
usedAlphabet.Dump();
alphabets[i].Dump();
if(usedAlphabet != alphabets[i] )
{
if(currentFileNmae!= s)
{
string.Format("{0}--{1}",s,alphabets[i]).Dump();
usedAlphabet = alphabets[i];
currentFileNmae = s;
}
}
break;
}
}
I am part of a team that's building a file renamer tool for our internal purposes and hence i need this code. This is part of the our enumertation functionality that we have planned.
Please suggest.
thanks

Try starting here:
using System.Diagnostics;
using System.IO;
string filename = #"C:\Foo\Bar.txt";
for (int count = 0; count < 100; count++)
{
char letter = (char)((int)'a' + count % 26);
string numeric = (count / 26) == 0 ? "" : (count / 26).ToString("000");
Debug.Print(Path.GetFileNameWithoutExtension(filename) + "_" + letter + numeric + Path.GetExtension(filename));
}
Substitute your own loop to go through the filenames and use Path to manipulate the pieces/parts of the names.
The renaming, IIRC, can be handled by File.Move. Surround it with a try/catch to implement the name collision logic.

Had no coffee yet, but this should do.
List<string> files = new List<string>();
int charIndex = 0;
int numericIndex = -1;
foreach (var file in files.Select(path => new FileInfo(path)))
{
// Create new Filename - This may needs some tuning
// to really remove only the extension ad the end
// It doesnt take care of things like
// file.bmp.bmp.bmp ...
string newFileName = String.Format("{0}_{1}{2}.{3}",
file.FullName.Replace(file.Extension,String.Empty),
(char)(charIndex++ + 97),
(numericIndex > -1 ? String.Format("{0:D4}", numericIndex) : String.Empty),
file.Extension);
// Rename the File
file.MoveTo(newFileName);
// Increment Counters.
if (charIndex > 25)
{
charIndex = 0;
numericIndex++;
}
}

You can try something like this
const string directory = #"C:\\wherever";
string[] fiNames = new string[]{ "abc", "pas", "etc",};
char[] alphabet = "abcdefghijklmnopqrstuvwxyz".ToCharArray();
int x = 0;
string ending = "";
for(int i = fiNames.Count()-1; i>=0; i--)
{
if(x%26==0)
{
x=0
if( ending=="")
ending="1";
else
ending=(System.Convert.ToInt32(ending)+1).ToString();
}
System.IO.File.Move(directory+fiNames[i], fiNames[i]+alphabet[x].ToString()+ending);
x++;
}

Checking a TXT Doc against anther TXT Doc

I will do what I can to get a snipit of the txt files on here for you to look at. most of them are class and it will take a bit of work for me to do that. The idea is to take a txt file with say a list of over 500 places run them against a list of 50 places and pull out the ones that match. As I said I have tried many diffrent ways, well all the ones I know, and I can not seem to get it to work right. I am trying to take the following code and have it do the above action. Does that help.
InPutBox = Input.Text;
int x = 1;
var lines = Input.Text.Split(new string[] { Environment.NewLine },StringSplitOptions.None);
for (var index = 0; index < lines.Length; index++)
{
var line = lines[index];
do
{
x++;
System.Console.WriteLine("'{0}'", InPutBox);
bool test1 = InPutBox.StartsWith("TAG");
bool test2 = InPutBox.EndsWith("TAG");
if (test1 && test2)
{
int first = InPutBox.IndexOf("TAG");
int last = InPutBox.LastIndexOf("TAG");
InPutBox = InPutBox.Substring(first, last - first);
}
}
while (x < 50);
System.Console.WriteLine("'{0}'", line);
if ((line.StartsWith("TAG") && line.EndsWith("TAG")))
{
MessageBox.Show("These are errors in line" + index + ": " + line);
break;
}
}