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Removing carriage return from specific line in c#

I have this type of data in a text file (csv) :
column1|column2|column3|column4|column5 (\r\n)
column1|column2|column3|column4|column5 (\r\n)
column1|column2 (\r\n)
column2 (\r\n)
column2|column3|column4|column5 (\r\n)
I would like to delete the \r\n that are line 3 and line 4 to have :
column1|column2|column3|column4|column5 (\r\n)
column1|column2|column3|column4|column5 (\r\n)
column1|column2/column2/column2|column3|column4|column5 (\r\n)
My idea is if the row doesn't have 4 column separators ("|") then delete the CRLF, and repeat the operation until you have only correct rows.
This is my code :
String path = "test.csv";
// Read file
string[] readText = File.ReadAllLines(path);
// Empty the file
File.WriteAllText(path, String.Empty);
int x = 0;
int countheaders = 0;
int countlines;
using (StreamWriter writer = new StreamWriter(path))
{
foreach (string s in readText)
{
if (x == 0)
{
countheaders = s.Where(c => c == '|').Count();
x = 1;
}
countlines = 0;
countlines = s.Where(d => d == '|').Count();
if (countlines == countheaders)
{
writer.WriteLine(s);
}
else
{
string s2 = s;
s2 = s2.ToString().TrimEnd('\r', '\n');
writer.Write(s2);
}
}
}
The problem is that i'm reading the file in one pass, so the line break on line 4 is removed and line 4 and line 5 are together...

You could probably do the following (cant test it now, but it should work):
IEnumerable<string> batchValuesIn(
IEnumerable<string> source,
string separator,
int size)
{
var counter = 0;
var buffer = new StringBuilder();
foreach (var line in source)
{
var values = line.Split(separator);
if (line.Length != 0)
{
foreach (var value in values)
{
buffer.Append(value);
counter++;
if (counter % size == 0)
{
yield return buffer.ToString();
buffer.Clear();
}
else
buffer.Append(separator);
}
}
}
if (buffer.Length != 0)
yield return buffer.ToString();
And you'd use it like:
var newLines = batchValuesIn(File.ReadLines(path), "|", 5);
The good thing about this solution is that you are never loading into memory the enitre orignal source. You simply build the lines on the fly.
DISCLAIMER: this may behave weirdly with malfomred input strings.

Is there an equivalent to mmap.mmap.rfind in C#?

While looking at memory-mapped files in C#, there was some difficulty in identifying how to search a file quickly forward and in reverse. My goal is to rewrite the following function in the language, but nothing could be found like the find and rfind methods used below. Is there a way in C# to quickly search a memory-mapped file using a particular substring?
#! /usr/bin/env python3
import mmap
import pathlib
# noinspection PyUnboundLocalVariable
def drop_last_line(path):
with path.open('r+b') as file:
with mmap.mmap(file.fileno(), 0, access=mmap.ACCESS_READ) as search:
for next_line in b'\r\n', b'\r', b'\n':
if search.find(next_line) >= 0:
break
else:
raise ValueError('cannot find any line delimiters')
end_1st = search.rfind(next_line)
end_2nd = search.rfind(next_line, 0, end_1st - 1)
file.truncate(0 if end_2nd < 0 else end_2nd + len(next_line))

Is there a way in C# to quickly search a memory-mapped file using a particular substring?
Do you know of any way to memory-map an entire file in C# and then treat it as a byte array?
Yes, it's quite easy to map an entire file into a view then to read it into a single byte array as the following code shows:
static void Main(string[] args)
{
var sourceFile= new FileInfo(#"C:\Users\Micky\Downloads\20180112.zip");
int length = (int) sourceFile.Length; // length of target file
// Create the memory-mapped file.
using (var mmf = MemoryMappedFile.CreateFromFile(sourceFile.FullName,
FileMode.Open,
"ImgA"))
{
var buffer = new byte[length]; // allocate a buffer with the same size as the file
using (var accessor = mmf.CreateViewAccessor())
{
var read=accessor.ReadArray(0, buffer, 0, length); // read the whole thing
}
// let's try searching for a known byte sequence. Change this to suit your file
var target = new byte[] {71, 213, 62, 204,231};
var foundAt = IndexOf(buffer, target);
}
}
I couldn't seem to find any byte searching method in Marshal or Array but you can use this search algorithm courtesy of Social MSDN as a start:
private static int IndexOf2(byte[] input, byte[] pattern)
{
byte firstByte = pattern[0];
int index = -1;
if ((index = Array.IndexOf(input, firstByte)) >= 0)
{
for (int i = 0; i < pattern.Length; i++)
{
if (index + i >= input.Length ||
pattern[i] != input[index + i]) return -1;
}
}
return index;
}
...or even this more verbose example (also courtesy Social MSDN, same link)
public static int IndexOf(byte[] arrayToSearchThrough, byte[] patternToFind)
{
if (patternToFind.Length > arrayToSearchThrough.Length)
return -1;
for (int i = 0; i < arrayToSearchThrough.Length - patternToFind.Length; i++)
{
bool found = true;
for (int j = 0; j < patternToFind.Length; j++)
{
if (arrayToSearchThrough[i + j] != patternToFind[j])
{
found = false;
break;
}
}
if (found)
{
return i;
}
}
return -1;
}

Parsing a huge text file(around 2GB) with custom delimiters

I have a huge text file around 2GB which I am trying to parse in C#.
The file has custom delimiters for rows and columns. I want to parse the file and extract the data and write to another file by inserting column header and replacing RowDelimiter by newline and ColumnDelimiter by tab so that I can get the data in tabular format.
sample data:
1'~'2'~'3#####11'~'12'~'13
RowDelimiter: #####
ColumnDelimiter: '~'
I keep on getting System.OutOfMemoryException on the following line
while ((line = rdr.ReadLine()) != null)
public void ParseFile(string inputfile,string outputfile,string header)
{
using (StreamReader rdr = new StreamReader(inputfile))
{
string line;
while ((line = rdr.ReadLine()) != null)
{
using (StreamWriter sw = new StreamWriter(outputfile))
{
//Write the Header row
sw.Write(header);
//parse the file
string[] rows = line.Split(new string[] { ParserConstants.RowSeparator },
StringSplitOptions.None);
foreach (string row in rows)
{
string[] columns = row.Split(new string[] {ParserConstants.ColumnSeparator},
StringSplitOptions.None);
foreach (string column in columns)
{
sw.Write(column + "\\t");
}
sw.Write(ParserConstants.NewlineCharacter);
Console.WriteLine();
}
}
Console.WriteLine("File Parsing completed");
}
}
}

As mentioned already in the comments you won't be able to use ReadLine to handle this, you'll have to essentially process the data one byte - or character - at a time. The good news is that this is basically how ReadLine works anyway, so we're not losing a lot in this case.
Using a StreamReader we can read a series of characters from the source stream (in whatever encoding you need) into an array. Using that and a StringBuilder we can process the stream in chunks and check for separator sequences on the way.
Here's a method that will handle an arbitrary delimiter:
public static IEnumerable<string> ReadDelimitedRows(StreamReader reader, string delimiter)
{
char[] delimChars = delimiter.ToArray();
int matchCount = 0;
char[] buffer = new char[512];
int rc = 0;
StringBuilder sb = new StringBuilder();
while ((rc = reader.Read(buffer, 0, buffer.Length)) > 0)
{
for (int i = 0; i < rc; i++)
{
char c = buffer[i];
if (c == delimChars[matchCount])
{
if (++matchCount >= delimChars.Length)
{
// found full row delimiter
yield return sb.ToString();
sb.Clear();
matchCount = 0;
}
}
else
{
if (matchCount > 0)
{
// append previously matched portion of the delimiter
sb.Append(delimChars.Take(matchCount));
matchCount = 0;
}
sb.Append(c);
}
}
}
// return the last row if found
if (sb.Length > 0)
yield return sb.ToString();
}
This should handle any cases where part of your block delimiter can appear in the actual data.
In order to translate your file from the input format you describe to a simple tab-delimited format you could do something along these lines:
const string RowDelimiter = "#####";
const string ColumnDelimiter = "'~'";
using (var reader = new StreamReader(inputFilename))
using (var writer = new StreamWriter(File.Create(ouputFilename)))
{
foreach (var row in ReadDelimitedRows(reader, RowDelimiter))
{
writer.Write(row.Replace(ColumnDelimiter, "\t"));
}
}
That should process fairly quickly without eating up too much memory. Some adjustments might be required for non-ASCII output.

Read the data into a buffer and then do your parsing.
using (StreamReader rdr = new StreamReader(inputfile))
using (StreamWriter sw = new StreamWriter(outputfile))
{
char[] buffer = new char[256];
int read;
//Write the Header row
sw.Write(header);
string remainder = string.Empty;
while ((read = rdr.Read(buffer, 0, 256)) > 0)
{
string bufferData = new string(buffer, 0, read);
//parse the file
string[] rows = bufferData.Split(
new string[] { ParserConstants.RowSeparator },
StringSplitOptions.None);
rows[0] = remainder + rows[0];
int completeRows = rows.Length - 1;
remainder = rows.Last();
foreach (string row in rows.Take(completeRows))
{
string[] columns = row.Split(
new string[] {ParserConstants.ColumnSeparator},
StringSplitOptions.None);
foreach (string column in columns)
{
sw.Write(column + "\\t");
}
sw.Write(ParserConstants.NewlineCharacter);
Console.WriteLine();
}
}
if(reamainder.Length > 0)
{
string[] columns = remainder.Split(
new string[] {ParserConstants.ColumnSeparator},
StringSplitOptions.None);
foreach (string column in columns)
{
sw.Write(column + "\\t");
}
sw.Write(ParserConstants.NewlineCharacter);
Console.WriteLine();
}
Console.WriteLine("File Parsing completed");
}

The problem you have is that you are eagerly consuming the whole file and placing it in memory. Attempting to split a 2GB file in memory is going to be problematic, as you now know.
Solution? Consume one lime a time. Because your file doesn't have a standard line separator you'll have to implement a custom parser that does this for you. The following code does just that (or I think it does, I haven't tested it). Its probably very improvable from a performance perspective but it should at least get you started in the right direction (c#7 syntax):
public static IEnumerable<string> GetRows(string path, string rowSeparator)
{
bool tryParseSeparator(StreamReader reader, char[] buffer)
{
var count = reader.Read(buffer, 0, buffer.Length);
if (count != buffer.Length)
return false;
return Enumerable.SequenceEqual(buffer, rowSeparator);
}
using (var reader = new StreamReader(path))
{
int peeked;
var rowBuffer = new StringBuilder();
var separatorBuffer = new char[rowSeparator.Length];
while ((peeked = reader.Peek()) > -1)
{
if ((char)peeked == rowSeparator[0])
{
if (tryParseSeparator(reader, separatorBuffer))
{
yield return rowBuffer.ToString();
rowBuffer.Clear();
}
else
{
rowBuffer.Append(separatorBuffer);
}
}
else
{
rowBuffer.Append((char)reader.Read());
}
}
if (rowBuffer.Length > 0)
yield return rowBuffer.ToString();
}
}
Now you have a lazy enumeration of rows from your file, and you can process it as you intended to:
foreach (var row in GetRows(inputFile, ParserConstants.RowSeparator))
{
var columns = line.Split(new string[] {ParserConstants.ColumnSeparator},
StringSplitOptions.None);
//etc.
}

I think this should do the trick...
public void ParseFile(string inputfile, string outputfile, string header)
{
int blockSize = 1024;
using (var file = File.OpenRead(inputfile))
{
using (StreamWriter sw = new StreamWriter(outputfile))
{
int bytes = 0;
int parsedBytes = 0;
var buffer = new byte[blockSize];
string lastRow = string.Empty;
while ((bytes = file.Read(buffer, 0, buffer.Length)) > 0)
{
// Because the buffer edge could split a RowDelimiter, we need to keep the
// last row from the prior split operation. Append the new buffer to the
// last row from the prior loop iteration.
lastRow += Encoding.Default.GetString(buffer,0, bytes);
//parse the file
string[] rows = lastRow.Split(new string[] { ParserConstants.RowSeparator }, StringSplitOptions.None);
// We cannot process the last row in this set because it may not be a complete
// row, and tokens could be clipped.
if (rows.Count() > 1)
{
for (int i = 0; i < rows.Count() - 1; i++)
{
sw.Write(new Regex(ParserConstants.ColumnSeparator).Replace(rows[i], "\t") + ParserConstants.NewlineCharacter);
}
}
lastRow = rows[rows.Count() - 1];
parsedBytes += bytes;
// The following statement is not quite true because we haven't parsed the lastRow.
Console.WriteLine($"Parsed {parsedBytes.ToString():N0} bytes");
}
// Now that there are no more bytes to read, we know that the lastrow is complete.
sw.Write(new Regex(ParserConstants.ColumnSeparator).Replace(lastRow, "\t"));
}
}
Console.WriteLine("File Parsing completed.");
}

Late to the party here, but in case anyone else want to know easy way to load such large CSV file with custom delimiters, Cinchoo ETL does the job for you.
using (var parser = new ChoCSVReader("CustomNewLine.csv")
.WithDelimiter("~")
.WithEOLDelimiter("#####")
)
{
foreach (dynamic x in parser)
Console.WriteLine(x.DumpAsJson());
}
Disclaimer: I'm the author of this library.

Stream read line

I have a stream reader line by line (sr.ReadLine()). My code counts the line-end with both line endings \r\n and/or \n.
StreamReader sr = new System.IO.StreamReader(sPath, enc);
while (!sr.EndOfStream)
{
// reading 1 line of datafile
string sLine = sr.ReadLine();
...
How to tell to code (instead of universal sr.ReadLine()) that I want to count new line only a full \r\n and not the \n?

It is not possible to do this using StreamReader.ReadLine.
As per msdn:
A line is defined as a sequence of characters followed by a line feed
("\n"), a carriage return ("\r"), or a carriage return immediately
followed by a line feed ("\r\n"). The string that is returned does not
contain the terminating carriage return or line feed. The returned
value is null if the end of the input stream is reached.
So yoг have to read this stream byte-by-byte and return line only if you've captured \r\n
EDIT
Here is some code sample
private static IEnumerable<string> ReadLines(StreamReader stream)
{
StringBuilder sb = new StringBuilder();
int symbol = stream.Peek();
while (symbol != -1)
{
symbol = stream.Read();
if (symbol == 13 && stream.Peek() == 10)
{
stream.Read();
string line = sb.ToString();
sb.Clear();
yield return line;
}
else
sb.Append((char)symbol);
}
yield return sb.ToString();
}
You can use it like
foreach (string line in ReadLines(stream))
{
//do something
}

you cannot do it with ReadLine, but you can do instead:
stream.ReadToEnd().Split(new[] {"\r\n"}, StringSplitOptions.None)

For simplification, let's work over a byte array:
static int NumberOfNewLines(byte[] data)
{
int count = 0;
for (int i = 0; i < data.Length - 1; i++)
{
if (data[i] == '\r' && data[i + 1] == '\n')
count++;
}
return count;
}
If you care about efficiency, optimize away, but this should work.
You can get the bytes of a file by using System.IO.File.ReadBytes(string filename).

How to read last "n" lines of log file [duplicate]

This question already has answers here:
Get last 10 lines of very large text file > 10GB
(21 answers)
Closed 1 year ago.
need a snippet of code which would read out last "n lines" of a log file. I came up with the following code from the net.I am kinda new to C sharp. Since the log file might be
quite large, I want to avoid overhead of reading the entire file.Can someone suggest any performance enhancement. I do not really want to read each character and change position.
var reader = new StreamReader(filePath, Encoding.ASCII);
reader.BaseStream.Seek(0, SeekOrigin.End);
var count = 0;
while (count <= tailCount)
{
if (reader.BaseStream.Position <= 0) break;
reader.BaseStream.Position--;
int c = reader.Read();
if (reader.BaseStream.Position <= 0) break;
reader.BaseStream.Position--;
if (c == '\n')
{
++count;
}
}
var str = reader.ReadToEnd();

Your code will perform very poorly, since you aren't allowing any caching to happen.
In addition, it will not work at all for Unicode.
I wrote the following implementation:
///<summary>Returns the end of a text reader.</summary>
///<param name="reader">The reader to read from.</param>
///<param name="lineCount">The number of lines to return.</param>
///<returns>The last lneCount lines from the reader.</returns>
public static string[] Tail(this TextReader reader, int lineCount) {
var buffer = new List<string>(lineCount);
string line;
for (int i = 0; i < lineCount; i++) {
line = reader.ReadLine();
if (line == null) return buffer.ToArray();
buffer.Add(line);
}
int lastLine = lineCount - 1; //The index of the last line read from the buffer. Everything > this index was read earlier than everything <= this indes
while (null != (line = reader.ReadLine())) {
lastLine++;
if (lastLine == lineCount) lastLine = 0;
buffer[lastLine] = line;
}
if (lastLine == lineCount - 1) return buffer.ToArray();
var retVal = new string[lineCount];
buffer.CopyTo(lastLine + 1, retVal, 0, lineCount - lastLine - 1);
buffer.CopyTo(0, retVal, lineCount - lastLine - 1, lastLine + 1);
return retVal;
}

Had trouble with your code. This is my version. Since its' a log file, something might be writing to it, so it's best making sure you're not locking it.
You go to the end. Start reading backwards until you reach n lines. Then read everything from there on.
int n = 5; //or any arbitrary number
int count = 0;
string content;
byte[] buffer = new byte[1];
using (FileStream fs = new FileStream("text.txt", FileMode.Open, FileAccess.Read, FileShare.ReadWrite))
{
// read to the end.
fs.Seek(0, SeekOrigin.End);
// read backwards 'n' lines
while (count < n)
{
fs.Seek(-1, SeekOrigin.Current);
fs.Read(buffer, 0, 1);
if (buffer[0] == '\n')
{
count++;
}
fs.Seek(-1, SeekOrigin.Current); // fs.Read(...) advances the position, so we need to go back again
}
fs.Seek(1, SeekOrigin.Current); // go past the last '\n'
// read the last n lines
using (StreamReader sr = new StreamReader(fs))
{
content = sr.ReadToEnd();
}
}

A friend of mine uses this method (BackwardReader can be found here):
public static IList<string> GetLogTail(string logname, string numrows)
{
int lineCnt = 1;
List<string> lines = new List<string>();
int maxLines;
if (!int.TryParse(numrows, out maxLines))
{
maxLines = 100;
}
string logFile = HttpContext.Current.Server.MapPath("~/" + logname);
BackwardReader br = new BackwardReader(logFile);
while (!br.SOF)
{
string line = br.Readline();
lines.Add(line + System.Environment.NewLine);
if (lineCnt == maxLines) break;
lineCnt++;
}
lines.Reverse();
return lines;
}

Does your log have lines of similar length? If yes, then you can calculate average length of the line, then do the following:
seek to end_of_file - lines_needed*avg_line_length (previous_point)
read everything up to the end
if you grabbed enough lines, that's fine. If no, seek to previous_point - lines_needed*avg_line_length
read everything up to previous_point
goto 3
memory-mapped file is also a good method -- map the tail of file, calculate lines, map the previous block, calculate lines etc. until you get the number of lines needed

Here is my answer:-
private string StatisticsFile = #"c:\yourfilename.txt";
// Read last lines of a file....
public IList<string> ReadLastLines(int nFromLine, int nNoLines, out bool bMore)
{
// Initialise more
bMore = false;
try
{
char[] buffer = null;
//lock (strMessages) Lock something if you need to....
{
if (File.Exists(StatisticsFile))
{
// Open file
using (StreamReader sr = new StreamReader(StatisticsFile))
{
long FileLength = sr.BaseStream.Length;
int c, linescount = 0;
long pos = FileLength - 1;
long PreviousReturn = FileLength;
// Process file
while (pos >= 0 && linescount < nFromLine + nNoLines) // Until found correct place
{
// Read a character from the end
c = BufferedGetCharBackwards(sr, pos);
if (c == Convert.ToInt32('\n'))
{
// Found return character
if (++linescount == nFromLine)
// Found last place
PreviousReturn = pos + 1; // Read to here
}
// Previous char
pos--;
}
pos++;
// Create buffer
buffer = new char[PreviousReturn - pos];
sr.DiscardBufferedData();
// Read all our chars
sr.BaseStream.Seek(pos, SeekOrigin.Begin);
sr.Read(buffer, (int)0, (int)(PreviousReturn - pos));
sr.Close();
// Store if more lines available
if (pos > 0)
// Is there more?
bMore = true;
}
if (buffer != null)
{
// Get data
string strResult = new string(buffer);
strResult = strResult.Replace("\r", "");
// Store in List
List<string> strSort = new List<string>(strResult.Split('\n'));
// Reverse order
strSort.Reverse();
return strSort;
}
}
}
}
catch (Exception ex)
{
System.Diagnostics.Debug.WriteLine("ReadLastLines Exception:" + ex.ToString());
}
// Lets return a list with no entries
return new List<string>();
}
const int CACHE_BUFFER_SIZE = 1024;
private long ncachestartbuffer = -1;
private char[] cachebuffer = null;
// Cache the file....
private int BufferedGetCharBackwards(StreamReader sr, long iPosFromBegin)
{
// Check for error
if (iPosFromBegin < 0 || iPosFromBegin >= sr.BaseStream.Length)
return -1;
// See if we have the character already
if (ncachestartbuffer >= 0 && ncachestartbuffer <= iPosFromBegin && ncachestartbuffer + cachebuffer.Length > iPosFromBegin)
{
return cachebuffer[iPosFromBegin - ncachestartbuffer];
}
// Load into cache
ncachestartbuffer = (int)Math.Max(0, iPosFromBegin - CACHE_BUFFER_SIZE + 1);
int nLength = (int)Math.Min(CACHE_BUFFER_SIZE, sr.BaseStream.Length - ncachestartbuffer);
cachebuffer = new char[nLength];
sr.DiscardBufferedData();
sr.BaseStream.Seek(ncachestartbuffer, SeekOrigin.Begin);
sr.Read(cachebuffer, (int)0, (int)nLength);
return BufferedGetCharBackwards(sr, iPosFromBegin);
}
Note:-
Call ReadLastLines with nLineFrom starting at 0 for the last line and nNoLines as the number of lines to read back from.
It reverses the list so the 1st one is the last line in the file.
bMore returns true if there are more lines to read.
It caches the data in 1024 char chunks - so it is fast, you may want to increase this size for very large files.
Enjoy!

This is in no way optimal but for quick and dirty checks with small log files I've been using something like this:
List<string> mostRecentLines = File.ReadLines(filePath)
// .Where(....)
// .Distinct()
.Reverse()
.Take(10)
.ToList()

Something that you can now do very easily in C# 4.0 (and with just a tiny bit of effort in earlier versions) is use memory mapped files for this type of operation. Its ideal for large files because you can map just a portion of the file, then access it as virtual memory.
There is a good example here.

As #EugeneMayevski stated above, if you just need an approximate number of lines returned, each line has roughly the same line length and you're more concerned with performance especially for large files, this is a better implementation:
internal static StringBuilder ReadApproxLastNLines(string filePath, int approxLinesToRead, int approxLengthPerLine)
{
//If each line is more or less of the same length and you don't really care if you get back exactly the last n
using (FileStream fs = new FileStream(filePath, FileMode.Open, FileAccess.Read, FileShare.ReadWrite))
{
var totalCharsToRead = approxLengthPerLine * approxLinesToRead;
var buffer = new byte[1];
//read approx chars to read backwards from end
fs.Seek(totalCharsToRead > fs.Length ? -fs.Length : -totalCharsToRead, SeekOrigin.End);
while (buffer[0] != '\n' && fs.Position > 0) //find new line char
{
fs.Read(buffer, 0, 1);
}
var returnStringBuilder = new StringBuilder();
using (StreamReader sr = new StreamReader(fs))
{
returnStringBuilder.Append(sr.ReadToEnd());
}
return returnStringBuilder;
}
}

Most log files have a DateTime stamp. Although can be improved, the code below works well if you want the log messages from the last N days.
/// <summary>
/// Returns list of entries from the last N days.
/// </summary>
/// <param name="N"></param>
/// <param name="cSEP">field separator, default is TAB</param>
/// <param name="indexOfDateColumn">default is 0; change if it is not the first item in each line</param>
/// <param name="bFileHasHeaderRow"> if true, it will not include the header row</param>
/// <returns></returns>
public List<string> ReadMessagesFromLastNDays(int N, char cSEP ='\t', int indexOfDateColumn = 0, bool bFileHasHeaderRow = true)
{
List<string> listRet = new List<string>();
//--- replace msFileName with the name (incl. path if appropriate)
string[] lines = File.ReadAllLines(msFileName);
if (lines.Length > 0)
{
DateTime dtm = DateTime.Now.AddDays(-N);
string sCheckDate = GetTimeStamp(dtm);
//--- process lines in reverse
int iMin = bFileHasHeaderRow ? 1 : 0;
for (int i = lines.Length - 1; i >= iMin; i--) //skip the header in line 0, if any
{
if (lines[i].Length > 0) //skip empty lines
{
string[] s = lines[i].Split(cSEP);
//--- s[indexOfDateColumn] contains the DateTime stamp in the log file
if (string.Compare(s[indexOfDateColumn], sCheckDate) >= 0)
{
//--- insert at top of list or they'd be in reverse chronological order
listRet.Insert(0, s[1]);
}
else
{
break; //out of loop
}
}
}
}
return listRet;
}
/// <summary>
/// Returns DateTime Stamp as formatted in the log file
/// </summary>
/// <param name="dtm">DateTime value</param>
/// <returns></returns>
private string GetTimeStamp(DateTime dtm)
{
// adjust format string to match what you use
return dtm.ToString("u");
}