Issue to C# code

Question

Issue to C# code

Peter_1985 2,806

Hi,

What is wrong below?

                var lines = File.ReadAllLines(@fileName);

                string lastLine = lines.Last();

                if (!lastLine.EndsWith("\r\n"))

                {

                    using (StreamWriter sw = new StreamWriter(@d0, true, Encoding.ASCII))

                    {

                        if (!b_err3)

                        {

                            sw.WriteLine($"Please check the lines having the issues below in the file - '" + fileName + "'.");

                            sw.WriteLine();

                        }

                        sw.WriteLine("It is missing CR and LF to the line below:");

                        sw.WriteLine(lastLine);  // ✅ Only the actual line

                        sw.WriteLine();

                        b_err3 = true;

                    }

                }

The above codes does claim no CR LF to this file

https://1drv.ms/u/c/17ec75244bac022f/ETMjfHBk_UJAu0CuAmFxVhEBffhquLVWYCtjCn9vd_88Pg?e=29fClN

But there is the proper CR LF on the last line of the file. Please help.

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Answer 1

Ravi Teja M 540

Hello Peter,

According to Microsoft Learn documentation, the File.ReadAllLines method removes line terminators (\r, \n, or \r\n) when reading lines into a string array, meaning the lines.Last() call will always return a string without the end-of-line characters, causing the code's condition to always evaluate as true. To accurately check for the presence of a newline at the end of a file, the content must be read in a way that preserves line endings, such as using File.ReadAllText which reads the entire file into a single string. For more details, visit Microsoft Learn.

Regards,

Raviteja M.

Peter_1985 2,806 Reputation points

2025-10-23T08:35:08.87+00:00

How to read every line and detect any missing CR (or LF) on each line? Further to this

var lines = File.ReadAllText(@fileName);

how to get each line including the last one, and check it line by line?

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Issue to C# code

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