Develop Reference

C# File.AppendText(path) Access to path denied

I know this is a common problem with a lot of related topics on here. But none of them seem to work for me.
I have code that works on a production system that I've copied across to my local home computer:
private static void WriteToLog(string logText, string logPath)
{
try
{
using (StreamWriter outputFile = File.AppendText(logPath))
{
outputFile.WriteLine(DateTime.Now.ToString() + "|| " + Regex.Replace(logText, #"\t|\n|\r", ""));
}
}
catch (IOException ex)
{
//what do?
throw ex;
}
}
The line using (StreamWriter outputFile = File.AppendText(logPath)) throws the classic exception:
System.UnauthorizedAccessException: 'Access to the path
'C:\Users\Jaso\Documents\DataChecker_Logs\schema_a-academic_attainment.txt'
is denied.'
At runtime the path variable contains "C:\\Users\\Jaso\\Documents\\DataChecker_Logs\\schema_a-academic_attainment.txt"
The Security of the folder in question looks like this:
When I find the user the process is run under using WindowsIdentity.GetCurrent().Name;, the value returned is "DESKTOP-LMMBET3\\Jaso" which according to the folder's settings (above screenshot) is a principal with full control!!
Windows 10 machine.
GRRR!!!

Check the permission of the file itself not the folder
if you don't have the permission to access the file this error will be thrown
System.UnauthorizedAccessException

The given path's is not supported C#

I have an strange problem I have an app that scan a directory and gets a list of files. it processes each file by reading it and doing some stuff. it works fine in the development computer but when I deploy it to the client it gives me the error. Here is the code
public void ProcessIMFiles()
{
DirectoryInfo di = new DirectoryInfo(Globals.ITMDIR);
FileInfo[] Files = di.GetFiles("*.txt");
foreach(FileInfo file in Files)
{
try
{
processThisIMFile(file.FullName);
movefile(file.FullName);
}
catch (Exception ex)
{
MessageBox.Show("error : " + ex.Message);
}
}
}
The error happens in the call to processThisIMFile(file.FullName) see below.
Globals.ITMDIR is a valid path.
private void processThisIMFile(string FileName)
{
string[] Fields = null;
setconnection();
DataTable dt = null;
try
{
string[] Lines = System.IO.File.ReadAllLines(FileName);
foreach (string line in Lines)
{
Fields = line.Split(Globals.delimiter);
if (Fields.Length == 7)
{
//stuff happens here
}
}//Try
catch (Exception e)
{
if (Interactive)
{
MessageBox.Show("Error in the Path: ->" + FileName);
writeToLog(true, "error opening file " + FileName);
}
}
}//end of processThisItemFile
the error happens in the "string[] Lines = System.IO.File.ReadAllLines(FileName)"
line. FileName comes from the di.GetFiles("*.txt"); when I show the actual path it looks ok to me. I have tried with UNC paths and with drive letters path as in C:\tmp\filename.txt or \\server\tmp\filename.txt both fail in the deplopyment machine with "The given path's is not supported" but it works fine in the development machine.
What is going on?

I'm wondering if this could be related to file.fullname somehow altering the file path string and giving an unacceptable result. Can you troubleshoot by using processThisIMFile(Path.GetFullPath(file))? Also, use messagebox.show(file.FullName) prior to processthisimfile to confirm that the result is as expected.

How to prevent Directory.GetFiles to "check" recycle bin and other "unsafe" places?

So guys, I have a function in my application which to search for certain file in certain directory using GetFiles method
System.IO.Directory.GetFiles(string path, string searchPattern, System.IO.SearchOption)
It works fine, until when I choose drive directory (D:\ or C:\ and such) to be searched, because it's also accessing the Recycle Bin, and then restricted
Access to the path 'D:\$RECYCLE.BIN\S-1-5-21-106145493-3722843178-2978326776-1010' is denied.
It's also need to be able to search subfolders (SearchOption.AllDirectories) too.
How to SKIP such place to be searched? Because there may be any other folder which access also denied.
I capitalize SKIP because if I use try catch and an exception caught, then the entire search will also fail.
Thanks. Please clarify anything you need.

EDITed for more clarity.
When recursively scanning a directory tree, say using a recursive method which takes the directory to start with as a parameter, you can get the attributes of the directory. Then check whether it's a system directory AND NOT a root directory like "C:\" - in that case you want to skip that directory, as it may be, for instance, the recycle bin.
Here's some code that does this, and also catches some common exceptions which occurred when I fiddled with directory scanning.
void scan_dir(string path)
{
// Exclude some directories according to their attributes
string[] files = null;
string skipReason = null;
var dirInfo = new DirectoryInfo( path );
var isroot = dirInfo.Root.FullName.Equals( dirInfo.FullName );
if ( // as root dirs (e.g. "C:\") apparently have the system + hidden flags set, we must check whether it's a root dir, if it is, we do NOT skip it even though those attributes are present
(dirInfo.Attributes.HasFlag( FileAttributes.System ) && !isroot) // We must not access such folders/files, or this crashes with UnauthorizedAccessException on folders like $RECYCLE.BIN
)
{ skipReason = "system file/folder, no access";
}
if ( null == skipReason )
{ try
{ files = Directory.GetFiles( path );
}
catch (UnauthorizedAccessException ex)
{ skipReason = ex.Message;
}
catch (PathTooLongException ex)
{ skipReason = ex.Message;
}
}
if (null != skipReason)
{ // perhaps do some error logging, stating skipReason
return; // we skip this directory
}
foreach (var f in files)
{ var fileAttribs = new FileInfo( f ).Attributes;
// do stuff with file if the attributes are to your liking
}
try
{ var dirs = Directory.GetDirectories( path );
foreach (var d in dirs)
{ scan_dir( d ); // recursive call
}
}
catch (PathTooLongException ex)
{ Trace.WriteLine(ex.Message);
}
}

Process.Start() and PATH environment variable

I have the following trivial C# application that simply attempts to launch "jconsole.exe", which on my machine is located in C:\Programs\jdk16\bin.
using System;
using System.Diagnostics;
namespace dnet {
public class dnet {
static void Main( string[] args ) {
try {
Process.Start("jconsole.exe");
Console.WriteLine("Success!");
} catch (Exception e) {
Console.WriteLine("{0} Exception caught.", e);
}
}
}
}
If my PATH environment variable is set to
c:\windows;c:\windows\sytem32;c:\programs\jdk16\bin
it works perfectly. However, if the PATH environment variable is set to
c:\windows;c:\windows\sytem32;c:\\programs\jdk16\bin
(note the two backslashes between "c:" and "programs"), it fails with a win32 exception.
System.ComponentModel.Win32Exception (0x80004005): The system cannot find the file specified
at System.Diagnostics.Process.StartWithShellExecuteEx(ProcessStartInfo startInfo)
at System.Diagnostics.Process.Start(ProcessStartInfo startInfo)
at dnet.dnet.Main(String[] args)
Interestingly, in the same command prompt where I run the .NET program and get the exception, I can simply type "jconsole.exe", and the program will start. Windows appears to have no trouble finding the executable with the double backslash in the PATH, but Process.Start() does.
Why is the extra backslash in the PATH causing problems, and how I can get around the problem? I don't know where the executable I want to call will be located at runtime, so I'd rather rely on the PATH variable.

Not quite sure why the problem occurs. Though, I can think of one solution that works on my machine:
var enviromentPath = System.Environment.GetEnvironmentVariable("PATH");
Console.WriteLine(enviromentPath);
var paths = enviromentPath.Split(';');
var exePath = paths.Select(x => Path.Combine(x, "mongo.exe"))
.Where(x => File.Exists(x))
.FirstOrDefault();
Console.WriteLine(exePath);
if (string.IsNullOrWhiteSpace(exePath) == false)
{
Process.Start(exePath);
}
I did find one para which gave me the idea for this solution. From the documentation for Process.Start
If you have a path variable declared in your system using quotes, you
must fully qualify that path when starting any process found in that
location. Otherwise, the system will not find the path. For example,
if c:\mypath is not in your path, and you add it using quotation
marks: path = %path%;"c:\mypath", you must fully qualify any process
in c:\mypath when starting it.
The way I read it, even though the PATH variable contained a valid path that Windows is able to use, Process.Start is unable to use it and needs the fully qualified path .

You can solve it if you first create a ProcessStartInfo.
ProcessStartInfo psi = new ProcessStartInfo("jconsole.exe");
StringDictionary dictionary = psi.EnvironmentVariables;
// Manipulate dictionary...
psi.EnvironmentVariables["PATH"] = dictionary.Replace(#"\\", #"\");
Process.Start(psi);
You'll have to find out yourself how to manipulate the PATH to let it work for you. But this should solve any issues you might have with your PATH variable.

The accepted answer is incorrect.
cmd.exe will find applications with executable extensions first.
So when you have the files puma and puma.bat in C:\Ruby\bin\, then puma.bat will take precedence over puma.
If you start c:\ruby\bin\puma.bat from c:\redmine, it will start puma with current working directory c:\ruby\bin, and your web application will work.
However, if you start c:\ruby\bin\puma directly, it will start puma with the current working directory in c:\redmine and will subsequently fail.
So a corrected version looks more or less like this:
// FindAppInPathDirectories("ruby.exe");
public string FindAppInPathDirectories(string app)
{
string enviromentPath = System.Environment.GetEnvironmentVariable("PATH");
string[] paths = enviromentPath.Split(';');
foreach (string thisPath in paths)
{
string thisFile = System.IO.Path.Combine(thisPath, app);
string[] executableExtensions = new string[] { ".exe", ".com", ".bat", ".sh", ".vbs", ".vbscript", ".vbe", ".js", ".rb", ".cmd", ".cpl", ".ws", ".wsf", ".msc", ".gadget" };
foreach (string extension in executableExtensions)
{
string fullFile = thisFile + extension;
try
{
if (System.IO.File.Exists(fullFile))
return fullFile;
}
catch (System.Exception ex)
{
Log("{0}:\r\n{1}",
System.DateTime.Now.ToString(m_Configuration.DateTimeFormat, System.Globalization.CultureInfo.InvariantCulture)
, "Error trying to check existence of file \"" + fullFile + "\""
);
Log("Exception details:");
Log(" - Exception type: {0}", ex.GetType().FullName);
Log(" - Exception Message:");
Log(ex.Message);
Log(" - Exception Stacktrace:");
Log(ex.StackTrace);
} // End Catch
} // Next extension
} // Next thisPath
foreach (string thisPath in paths)
{
string thisFile = System.IO.Path.Combine(thisPath, app);
try
{
if (System.IO.File.Exists(thisFile))
return thisFile;
}
catch (System.Exception ex)
{
Log("{0}:\r\n{1}",
System.DateTime.Now.ToString(m_Configuration.DateTimeFormat, System.Globalization.CultureInfo.InvariantCulture)
, "Error trying to check existence of file \"" + thisFile + "\""
);
Log("Exception details:");
Log(" - Exception type: {0}", ex.GetType().FullName);
Log(" - Exception Message:");
Log(ex.Message);
Log(" - Exception Stacktrace:");
Log(ex.StackTrace);
} // End Catch
} // Next thisPath
return app;
} // End Function FindAppInPathDirectories

Trouble Moving files in C#?

I am making a software that will move files from the downloads folder to a specific sub folder in a directory. The sub folder is selected by the user by a combobox. I keep getting this error: System.IO.IOException: Cannot create a file when that file already exists. Also, these error come up on people's computer who install my program...exceptions and things. How do i turn it off. Also, why do i get this error? Here is my code:
string pathUser4 = Environment.GetFolderPath(Environment.SpecialFolder.UserProfile);
string pathDownload4 = (pathUser4 + #"\Downloads\");
string sourceFile = pathDownload4 + listBox1.Text;
string pathdoc5 = Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments);
string pathDownload5 = (pathdoc5 + #"\iracing\setups\");
string destinationFile = pathDownload5 + comboBox1.Text;
File.Move(sourceFile, destinationFile);
if (comboBox1.Text == "Select File Destination")
{
MessageBox.Show("Please Select A Destination Folder", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
}

Each File.Move should be wrapped in a try/catch block as you can never expect an IO operation to execute without error. It could be something as simple as the user having a file handle open, or the file existing in the destination folder, either way, you don't want a single file to throw an exception that stops the entire operation. You will want to catch the exceptions and log them either to an error log file or to the event log, this way you can see the errors that occurred but it will not interrupt anything.
Secondly, for any desktop application I would add global error handling to log any uncaught errors. You can do this by putting this code at the beginning of your program,
AppDomain.CurrentDomain.UnhandledException += (a, exception) => File.AppendAllText("errorlog.txt", exception.ToString() + "\n"
This will keep the user from ever seeing ugly exceptions being thrown. Also be sure you are not giving the users the .pdb files as this will cause exceptions to contain paths of the computer it was compiled on which can contain your username and other sensitive information you wouldn't want a client to see.
You can register the global exception handling when the main window is initialized, you want it to be the first thing you do before any thing else because again you never know when an exception will be thrown so you have to think defensively.
public partial class MainWindow : Window
{
public MainWindow()
{
AppDomain.CurrentDomain.UnhandledException += (a, exception) => File.AppendAllText("errorlog.txt", exception.ToString() + "\n");
InitializeComponent();
}
}
C# uses exceptions extensively so it will be good concept for you to study up on if you are not familiar with this type of error handling. All exceptions derive from the Exception class so when you write catch (Exception e) this will catch all exceptions (because a base reference can hold an object of a derived type), however if you know the specific exception a method will throw you can catch a more specific exception (always before the more general catch) and handle it in a specific way. In this example you may have an IOException from the File.Move() that you want to catch and handle differently.
try
{
string pathUser4 = Environment.GetFolderPath(Environment.SpecialFolder.UserProfile);
string pathDownload4 = (pathUser4 + #"\Downloads\");
string sourceFile = pathDownload4 + listBox1.Text;
string pathdoc5 = Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments);
string pathDownload5 = (pathdoc5 + #"\iracing\setups\");
string destinationFile = pathDownload5 + comboBox1.Text;
File.Move(sourceFile, destinationFile);
if (comboBox1.Text == "Select File Destination")
{
MessageBox.Show("Please Select A Destination Folder", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
}
}
catch (Exception e)
{
File.AppendAllText("ErrorLog.txt", e.ToString() + "\n");
}

The example code from MSDN for File.Move should get you pointed at the various things you need to deal with, such as an already existing file and basic error handling.
using System;
using System.IO;
class Test
{
public static void Main()
{
string path = #"c:\temp\MyTest.txt";
string path2 = #"c:\temp2\MyTest.txt";
try
{
if (!File.Exists(path))
{
// This statement ensures that the file is created,
// but the handle is not kept.
using (FileStream fs = File.Create(path)) {}
}
// Ensure that the target does not exist.
if (File.Exists(path2))
File.Delete(path2);
// Move the file.
File.Move(path, path2);
Console.WriteLine("{0} was moved to {1}.", path, path2);
// See if the original exists now.
if (File.Exists(path))
{
Console.WriteLine("The original file still exists, which is unexpected.");
}
else
{
Console.WriteLine("The original file no longer exists, which is expected.");
}
}
catch (Exception e)
{
Console.WriteLine("The process failed: {0}", e.ToString());
}
}
}

The error may caused by your code, or by some invalid input.
As #Despertar mentioned, I suggest all the program include error handling and log features in your code. It will be very helpful for your debug.
But I suggest use open source log library, not do it by yourself. For example, log4net, NLog, etc.